RU2806318C2 - Coil frame, inductive component and method for adjusting inductance - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: coil frame (1) for the inductive component (7) contains a main element (2), some areas of which are wrapped with electrically insulating foil (3). The coil frame (1) is designed as a holder for the winding wire (8). The inductive component (7) includes a winding (9) containing a winding wire (8), which is wound around a coil frame (1) such that the foil (3) is located between the winding wire (8) and the main element (2). The electrically insulating foil (3) extends over no more than two thirds of the maximum possible effective length of the foil (3) in which the electrically insulating foil (3) is present under the entire winding (9) so that in some areas the winding conductor (8) rests on top of the foil (3), in some areas the winding wire was located directly on the main element (2), and the diameter of the winding (9) in the area in which the winding wire is located on top of the foil (3) was increased. In the inductance adjustment method, the length of the foil (3) is selected depending on the target inductance value.

EFFECT: increase of the accuracy of adjustment of the inductive component.

10 cl, 3 dwg

Description

The present invention relates to a coil frame for an inductive component and to an inductive component comprising a coil frame with a wire winding. This could be an air core coil, i.e. coil without a magnetic core. This inductive component is used, among other things, in stereo systems.

In many applications, it is desirable to finely control the value of a component's inductance, at least within the statistical average of a batch of inductors. In particular, resonance-related applications require very precise inductance adjustment.

Geometric dimensions greatly influence the inductance of electrical components, particularly in the case of air-core coils. Highly accurate inductance values can only be achieved within certain physical limits and require precise geometry control. For inductors with or without a ferrite core, changes in material properties and operating temperature will also change the inductance value. Correcting deviations of the finished component's inductance value from the desired target value is called "adjustment" or "tuning".

The documents DE 36 18 122 A1, DE 39 26 231 A1, DE 199 52 192 A1 and DE 10 2008 063 312 A1 describe adjustable inductive components. Adjustment is usually accomplished by pushing a core of soft magnetic material into or out of the inside of the winding, or by pushing the winding apart or contracting it.

It is an object of the present invention to provide an improved coil frame, an improved inductive component, and a method for adjusting the inductance of the inductive component.

According to the first aspect of the present invention, the coil frame is configured as a holder for a winding wire of an inductive component. The coil frame contains a main element, at least some areas of which are wrapped with electrically insulating foil. The diameter of the coil frame is selectively increased by wrapping it with foil. In this way, the inductance can be specifically adjusted after winding the winding wire onto the coil frame and over at least some portions of the foil.

In one embodiment, the main element of the coil frame is made of a non-magnetic material. For example, it could be a plastic material. Thus, the inductive component can be designed as an air-core coil, i.e., without a magnetic core around which the winding wire is wound. Thus, the coil frame functions solely as a holder for the winding wire and does not direct magnetic flux. In such an embodiment, the inductance is particularly dependent on the geometry, in particular the diameter of the coil, which allows precise fine tuning by changing the diameter.

For example, the thickness of the foil is significantly less than 1 mm. For example, the maximum foil thickness is 100 microns. In particular, the thickness of the foil can be from 10 to 40 microns.

In an alternative embodiment, the main element may be made of magnetic material. For example, it could be a ferrite core.

For example, the foil is wrapped spirally around the main element. Thus, the length of the foil and, with a fixed winding geometry, also the number of turns of the foil around the main element, can be determined depending on the target inductance value. For example, the number of revolutions varies from one to four revolutions.

In particular, the foil is arranged such that a winding wire wrapper can be placed over the foil wrapper. The geometry of the foil wrapper, in particular, corresponds to the geometry of the wire wrapper, with the foil wrapper preferably being shorter than the wire wrapper. The wire wrap can cover the entire length of the foil and extend beyond the foil. The winding wire can also cover the entire width of the foil.

Further in the text, the maximum possible effective length is the length of the foil at which the foil is present under the entire winding. Thus, the entire winding is applied to a larger diameter.

For example, in the first step, the foil is applied to half the maximum effective length possible, and then the winding is applied and the inductance of the component is measured. The length of the foil is then reduced or increased to produce the following components depending on the measured inductance value. Initially applying the foil over only a portion of the maximum possible length, such as over half, is intended to provide flexibility for fine adjustment of the length of the foil.

For example, the foil in the resulting component does not extend over the entire length of the main element, in particular, not over the maximum possible effective length of the foil. For example, the foil extends over no more than two-thirds of the length of the main element or the maximum possible effective length. For example, the foil extends over at least a third of the length of the main element or the maximum possible effective length. It is also possible that the foil may extend over the entire maximum possible effective length at first or in a configured component, or the foil may be missing.

Alternatively or optionally, it is also possible to adjust the diameter and thus the inductance by changing the thickness of the foil or the number of foil layers. The foil can be applied to the main element in one layer. However, to further vary the thickness, the foil can also be applied in multiple layers. For example, to adjust inductance, a certain number of foil layers are initially present, and then one or more layers are removed or added depending on the measured inductance value. The foil can also come in different thicknesses, and the thickness of the foil can be varied for fine tuning. For example, the foil always extends over the maximum effective length. In an alternative embodiment, a combination of changing the length and changing the number of layers or thickness of the foil is also possible.

In one embodiment, the foil is made of a non-magnetic material. For example, it could be a plastic material. The foil may contain the same material as the coil frame. Thus, the foil serves only to increase the diameter of the coil frame, and not to direct the magnetic flux.

The coil frame may include a recess in which the foil is located. The recess is configured to accurately accommodate the foil and/or accurately accommodate the winding wire.

For example, the recess is annular. In particular, the recess extends helically around the main element. The recess may extend only circumferentially around the main element in sections or extend circumferentially continuously around the main element. For example, the recess contains at least two turns, in particular continuous turns. For example, the recess extends at least along the entire length of the foil. The recess is preferably configured to not only accommodate the foil, but also accommodate the winding wire. The recess preferably extends over most of the length of the main element.

The recess contains transverse stops configured to guide the foil and/or winding wire, preventing them from sliding in a direction perpendicular to their travel in the direction of the main passage. The transverse stops may be formed from the material of the base element. The recesses can be formed, in particular, directly during the manufacture of the base element, for example during the injection molding process. It is also possible to have only one side stop for positioning.

For example, the foil is only slightly wider than the recess. The foil can also be the same width as the recess or be slightly wider than the recess. In this case, the foil can be fixed in the recess by clamping.

In accordance with a further aspect of the present invention, the inductive component includes a previously described coil frame and a winding wire wound around the coil frame. In at least some areas, in particular over some area of the length of the winding wire, the foil is located between the winding wire and the main element. Consequently, at least some areas of the outer diameter of the coil frame and thus the inner diameter of the winding are increased. This results in an increase in the inductance of the component.

For example, the winding wire is designed as a flat wire. In an alternative embodiment, the winding wire can also be designed as a round wire. It could be copper wire.

For example, the component inductance ranges from 1 to 1000 nH. For example, depending on the design, by changing the length of the foil, the inductance can be adjusted up to 10% of the inductance in steps of 0.1%.

The winding wire preferably extends over the entire length of the foil and, for example, also extends beyond the length of the foil. The foil and the winding wire are, in particular, made in the form of two homogeneous windings located one on top of the other. The winding wire being wound is preferably longer than the foil. Thus, the winding wire covers only part of the foil in the main direction of the foil. For example, the ends of the winding wire extend beyond the foil on both sides.

The winding wire preferably contains more turns than the foil. For example, the number of turns of the foil is no more than two-thirds of the number of turns of the winding wire. For example, the winding wire has eight turns, and the foil has five turns. Thus, there is sufficient flexibility to fine-tune the inductance.

Therefore, the diameter of the wire winding may vary in different areas. In particular, the diameter is larger in those places where the winding wire is located on top of the foil.

In accordance with one embodiment, the inductive component includes a coil frame with a recess, with at least some areas of foil and winding wire located within the recess. The recess can in particular be made as already described above for the coil frame. The recess may in particular be spiral and contain at least two turns. The winding wire may be slightly narrower than the recess. The winding wire can also be the same width as the recess or be slightly wider than the recess. In this case, the winding wire can be fixed in the recess by clamping.

in an alternative embodiment, the foil may also be adhered to the main element. For example, foil is self-adhesive. The foil can also be attached to the main element by means of applied adhesive. Likewise, the winding wire can be glued to the main element. It is also possible to first attach the foil to the winding wire, for example by gluing it to the winding wire, and then position and secure the winding wire to the main element along with the foil.

In an alternative embodiment, the winding wire and/or foil may also be attached to the main element by hot caulking. During the process, after placing the foil and winding wire in the recess, the radially protruding areas of the stoppers can be expanded using pressure and heat so that the stoppers at least partially cover the foil and winding wire. In this case also, the foil can be first attached by gluing, and then the winding wire can be attached by hot caulking.

In accordance with another aspect of the present invention, there is provided a method for adjusting the inductance value of an inductive component. In this case, at least some areas of the main element of the coil frame are wrapped in foil. The length of the foil is selected depending on the target inductance value. With a fixed geometry, the length corresponds to a certain number of turns of the foil.

The coil frame is then wrapped with winding wire such that the foil is positioned between the main member and the winding wire in at least some areas, particularly along some area of the winding wire. For example, the coil frame and the inductive component are configured as described above.

For example, to adjust the length of the foil, the inductance of an inductive component of the same design is measured. Inductance can also be measured indirectly, i.e. through another parameter, which is a measure of inductance. The foil length for the other inductive element can then be changed depending on the deviation of the measured value from the target value.

For example, the length is increased or decreased in discrete steps until the desired target value is achieved. For example, the number of revolutions is varied in the range from 1.00 to 4.00 revolutions. The increment in length change is less than one revolution, for example, 0.01 revolution.

In accordance with another aspect of the present invention, the coil frame for the inductive component includes a stop for positioning the winding wire.

The limiter is in particular configured to guide a section of winding wire in a central region of the winding; that is, at least one more turn of the winding wire is adjacent to this section on both sides. Therefore, this is not an edge section of the winding. For example, this section is guided on both sides by two limiters. Thus, the stops form a recess for receiving at least one section of winding wire.

In particular, the stop or recess extends helically around the main element of the coil frame. For example, the stop or recess contains at least two turns. The recess can be made in the main element of the coil frame. The recess may also be configured to position the foil as described above. However, the coil frame may also not contain foil. Otherwise, the frame can be made as described above.

In accordance with another aspect of the present invention, the inductive component includes such a coil frame with a recess in which the winding wire is located. For example, the winding wire is designed as a flat wire. The foil may be located between the winding wire and the main element of the coil frame. Also, such foil may be missing. Alternatively, the inductive component may be configured as described above. The winding wire is attached to the main element as described above, for example, by clamping, gluing or hot caulking.

The description of the objects provided herein is not limited to any particular embodiment. On the contrary, features of individual embodiments may be combined with each other based on technical feasibility.

The objects described herein are explained in more detail below with reference to schematic design examples.

The graphic materials show:

in Fig. 1 shows an embodiment of a coil frame (side view);

in Fig. 2 shows a side view of an embodiment of an inductive component;

in Fig. 3A to 3E are schematic illustrations of a method for adjusting inductance.

In the following figures, like reference numerals preferably refer to functionally or structurally equivalent parts of different embodiments.

In FIG. 1 shows a coil frame 1 for an inductive component. The coil frame 1 is designed as a holder for the winding wire.

In particular, the coil frame 1 is designed for an air-core coil, that is, a coil that does not have a magnetic core. The coil frame 1 is non-magnetic. The coil frame 1 may comprise a main element 2 made of plastic. For example, the coil frame 1 is manufactured by an injection molding process. The inductance of an air-core coil is largely determined by the geometry of the winding.

In one alternative embodiment, the coil frame 1 may also be made in the form of a magnetic core, for example, a ferrite core, or a magnetic core may be present in the coil frame 1.

The main element 2 in this case has a cylindrical shape. The main element 2 may also have a different shape, for example a cuboid shape. The main element 2 may also be part of a larger element, for example a ring element. The main element 2 can be made in the form of a hollow element.

Some areas of the main element 2 are wrapped with foil 3. The foil 3 serves to selectively increase the diameter of the main element 2.

The foil 3 is thin, allowing fine adjustment of the diameter of the main element 2 and thus the inductance of the component after winding the winding wire onto the foil 3. For example, the thickness of the foil 3 is from 10 μm to 40 μm. For example, the thickness of foil 3 is 25 μm. In this case, foil 3 is applied in one layer.

Foil 3 contains non-magnetic material. The foil 3 may contain plastic material or be made of plastic material. For example, the coil frame 1 and the foil 3 may be made of the same material. In other embodiments, the foil 3 may contain magnetic material.

By selectively changing the length of the foil 3 corresponding to the number of revolutions k, the region with an increased diameter can be selectively adjusted, thereby allowing the inductance of the resulting component to be adjusted. In this case, foil 3 passes through k=2.00 turns. For example, the number of revolutions of the foil 3 varies in the range k=1.00 to 4.00 revolutions. The variation is performed, for example, with an increment of 0.01 revolutions.

The coil frame 1 additionally contains a recess 4, which is configured to accurately position the foil 3 and/or the winding wire 8. The more precisely the foil 3 and/or the winding wire 8 can be positioned on the coil frame 1, the more precisely the inductance of the component can be adjusted.

The recess 4 extends circumferentially around the main element 2. In particular, the recess 4 extends helically around the main element 2 of the coil frame 1. The recess 4 is limited on both sides perpendicular to the circumferential direction by stops 5, 6. The stops 5, 6 similarly extend around the main element 2. Thus, the recess 4 is made in the form of a guide groove/channel along the circumference. In other words, the recess 4 is made in the form of a thread of a screw thread, and the stops 5, 6 are made in the form of sidewalls of a thread.

Foil 3 is placed in recess 4. The width of foil 3 is close to the width of recess 4. Foil 3 can be slightly narrower than recess 4. Foil 3 can also be the same width or slightly wider than recess 4 and be fixed in recess 4 by clamping or gluing.

The width of the winding wire 8 (see Fig. 2) can also be close to the width of the recess 4. For example, the width b of the recess 4 is no more than 25% greater than the width B of the winding wire.

Recess 4 contains n turns, in this case n=8. There may also be more or less than eight turns present. The recess preferably contains at least two turns.

In an alternative embodiment, the coil frame 1 does not have a recess 4 for positioning the winding wire, but contains a foil 3.

In another alternative embodiment, the coil frame 1 does not have a foil to increase the diameter, but contains a recess 4 for precise positioning of the winding wire.

In FIG. 2 shows an inductive component 7 comprising a coil frame 1 and a winding wire 8 wound around it, which thereby forms a winding 9. The coil frame 1 may be constructed in accordance with FIG. 1.

In this case, the winding wire 8 is made in the form of a flat wire. The main surface of the winding wire 8 lies on the main element 2 of the coil frame 1. In an alternative embodiment, the winding wire 8 can also be designed as a round wire. For example, this is a copper wire.

Wire 8 of the winding in this case contains m=7.50 turns. Thus, the maximum possible effective length of foil 3 is also 7.50 turns. Winding wire 8 can also have more or less turns.

The winding wire 8 includes two ends 10, 11. The ends 10, 11 extend, for example, to connect the component 7 to a contact pad (not shown) or are provided with another contact connector (not shown).

Some areas of the winding wire 8 are located on top of the foil 3. Thus, the foil 3 is located between the main member 2 of the coil frame 1 and the winding wire 8. In the area in which the winding wire 8 is located on top of the foil 3, the diameter of the winding 9 is increased. Thus, the winding wire 8 is located in some areas on top of the foil 3, and in some areas directly on the main element 2 depending on the length or number of turns k of the foil 3. Consequently, the diameter D of the winding 9 is increased only in some areas. The inductance of component 7 is increased depending on the size of the area with increased diameter.

Winding wire 8 is located in recess 4 for precise positioning. The width B of the winding wire 8 can be only slightly smaller than the width b of the recess 4. Thus, the position of the winding wire 8 is precisely determined by the recess 4. The width B of the winding wire 8 can also be slightly larger than the width b of the recess 2, so that the winding wire 8 is fixed between the stops 5, 6 by clamping. The winding wire 8 can also be fixed in the recess 2 by hot caulking. The radial end regions of the stops 5, 6 are in particular expanded by hot caulking in such a way that these end regions at least partially cover the winding wire 8 in a radially outward direction.

In one embodiment, the inductive component 6 does not have recesses in the coil frame 1 for positioning the wire of the winding 8, but contains foil, as shown in FIG. 1.

In this case, winding wire 8 is wound on coil frame 1 in one layer. In other embodiments, the winding wire 8 may also be wound onto the coil frame 1 in multiple layers.

In an alternative embodiment, the inductive component 7 has no foil between the main element 2 and the winding wire 8, but has a recess 4 for precise positioning of the winding wire 8. In this case, the diameter D of the winding 9 is uniform. Instead of a recess 4 with two stops 5, 6, there can also be only one stop 5, 6 for positioning on one side. In addition, the recess 4 or limiter 5, 6 can only be made in sections.

In FIG. 3A to 3E show steps of a method for adjusting the inductance of an inductive component.

According to FIG. 3A provide 1 coil frame. The coil frame 1 can be constructed similarly to the coil frame 1 shown in FIG. 1. The coil frame 1 may, but does not necessarily contain, a recess 4.

According to FIG. 3B, the length l of the foil 3 is determined, for example, depending on the target value, based on the input measured value M. This information can be obtained from the measured inductance value of the identical inductive component. If the measured inductance is less than the desired target value, select foil 3 with a longer length than the component that was used for measurement. If the measured inductance is less than the desired target value, select foil 3 with a shorter length than the component that was used for measurement.

The length l of foil 3 corresponds to the number of revolutions k for a given coil frame 1 and a given winding geometry. The number of revolutions k is varied, for example, with an increment of 0.01 revolutions. For example, the number of revolutions is adjusted in the range from 1.00 to 4.00 revolutions.

According to FIG. 3C, the foil 3 is wrapped around the main element 2. In this case, the predetermined number of turns is approximately 2.05. You can first wrap the foil 3 and then cut it to the desired length l. For precise positioning, the coil frame 1 may include a spiral recess 4 (see FIG. 1), and the foil 3 may be placed in the recess 4.

According to FIG. The 3D winding wire 8 is wound around the frame 1 to form a winding 9. The foil 3 selectively increases the diameter D of the winding 9, as shown schematically herein. The diameter of the component 7 varies depending on the thickness of the foil 3, in particular in the range of microns. The winding wire 8 is in this case significantly longer than the foil 3. The winding wire 8 contains at least one more turn than the foil 3. For example, the number of turns of the winding wire 8 is at least one third more than the number of turns k of the foil 3 .This provides a greater degree of freedom to adjust the inductance.

According to FIG. 3E, the measured inductance value M is determined after application of the winding 9. If the inductance is sufficiently close to the target value, the length l of the foil 3 is set for the group of components. If the target value has not yet been reached, the length l of the foil 3 is further changed based on the measured value M.

By adjusting the number of revolutions of the foil 3, a very precise adjustment of the inductance of the component 7 can be achieved. For example, depending on the design, the inductance can be adjusted very precisely in increments of 0.1%, over a range of up to 10%. For example, the target inductance of a component is 1 to 1000 nH.

List of item numbers

1 - coil frame

2 - main element

3 - foil

4 - recess

5 - limiter

6 - limiter

7 - inductive component

8 - winding wire

9 - winding

10 - end of the winding wire

11 - end of the winding wire

b - recess width

B - winding wire width

k - number of foil revolutions

n - number of revolutions of the recess

m - number of turns of the winding wire

D - winding diameter

M - measured value.

Claims (16)

1. An inductive component containing: coil frame, wherein coil frame (1) is made in the form of a holder for winding wire (8), wherein coil frame (1) contains a main element (2); electrically insulating foil (3), with some areas of the main element (2) wrapped in electrically insulating foil (3); a winding (9) containing a winding wire (8), which is wound around a coil frame (1) in such a way that the foil (3) is located between the winding wire (8) and the main element (2), wherein the electrically insulating foil (3) extends over no more than two-thirds of the maximum possible effective length of the foil (3), in which the electrically insulating foil (3) is present under the entire winding (9) so that in some areas the winding wire (8) is located on top of the foil (3), in some areas the winding wire was located directly on the main member (2), and the diameter of the winding (9) in the area where the winding wire is located on top of the foil (3) was increased. 2. An inductive component according to claim 1, wherein the main element (2) is made of a non-magnetic material. 3. An inductive component according to any of the previous paragraphs, wherein the foil (3) is made of a non-magnetic material. 4. An inductive component according to any of the previous paragraphs, wherein the thickness of the foil (3) is not more than 100 μm. 5. The inductive component according to any of the previous paragraphs, in which the coil frame (1) includes a recess (4), and the foil (3) is located in the recess (4). 6. Inductive component according to claim 5, in which the recess (4) is helical and contains at least two turns. 7. Inductive component according to any one of paragraphs. 5 or 6, characterized in that the winding wire (8) is located in the specified recess (4). 8. An inductive component according to any of the previous paragraphs, characterized in that the foil (3) is wrapped spirally around the main element (2), and the number of turns (k) of the foil (3) is not more than two thirds of the number of turns (m) of the wire (8) windings. 9. A method for adjusting the inductance value for a group of inductive components of the same design, characterized in that at least some areas of the main element (2) of the coil frame (1) are wrapped with electrically insulating foil (3), and the length of the foil (3) is selected depending on target inductance value, and then the coil frame (1) is wrapped with the winding wire (8) such that the foil (3) is located in at least some areas between the winding wire (8) and the main element (2), and the inductance of the component (7) is measured after the wire (8) is wrapped around the winding, and, if the target value has not yet been achieved, the length of the foil (3) for the additional inductive component (7) is changed depending on the deviation of the measured value from the target value, and if the measured inductance is less than the required target value, the foil (3) with a longer length is selected than that of the component being measured, for an additional inductive component (7), or, if the measured inductance is greater than the required target value, select foil (3) with a shorter length than that of the component being measured, or otherwise, if the target value is achieved, the length of the foil (3) is determined for the group of inductive components. 10. The method according to claim 9, characterized in that the foil (3) is wrapped spirally around the main element and the length (l) of the foil (3) is changed in increments less than one turn of the foil (3) around the coil frame (1).

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