JP7445900B2 - choke coil - Google Patents

Description

The present invention belongs to the technical field of choke coils.

Choke coils as electronic components are widely used in various devices. A noise filter including such a choke coil is described, for example, in Patent Document 1 listed below. The noise filter disclosed in Patent Document 1 below includes a magnetic core, a ground conductor, and two coils. Each of the coils has a coil portion wound around a magnetic core and two terminals drawn out from the coil portion. The ground conductor has a conductor main portion spaced apart from the coil portion and a ground terminal drawn out from the conductor main portion. The circuit board is provided with four electrodes connected to two terminals, respectively, and a ground electrode connected to a ground terminal. The combined capacitance Cp+Cw of the pattern capacitance Cp between each electrode and the winding capacitance Cw of the coil is 0.29×Cg-3 in relation to the ground capacitance Cg between the ground conductor and the coil. 06 or more and 0.29×Cg+2.15 or less.

JP 2020-9900 (Figure 2, etc.)

However, in view of the recent demands for improvements in electronic components such as miniaturization, higher output, and higher performance, further miniaturization, higher output, and higher performance are needed from the choke coil disclosed in Patent Document 1. It is hoped that the

The present invention has been made in view of the above-mentioned demands, and one example of the problem is to provide a choke coil that can be further downsized, have higher output, and have higher performance than conventional choke coils.

In order to solve the above problem, the invention according to claim 1 provides two first shafts each having a coil wound thereon via an insulating bobbin, the first shafts being parallel to each other and facing each other. a first shaft arranged in a columnar shape, and two second shafts arranged parallel to each other and facing each other, each in a columnar shape, and around which no coil is wound; Parallel second axes, the ends of each of the first axes, and the ends of each of the second axes corresponding to the ends are connected to a line connecting the first axes and each of the second axes. a plate-shaped connection part that connects the axes so that the lines intersect with each other, the connection part for passing the magnetic flux generated by the current flowing through each of the coils to the first axis and the second axis; two cores each having a core, two bobbins through which each of the first shafts is passed inside and the coil is wound on the outside, and each of the first shafts is wound around the first shaft via the bobbin. and the connecting portion is made of a ferrite material, both of the first shafts are made of a dust-based material, and both of the second shafts are made of the ferrite material, or both of the second shafts are made of the ferrite material. The magnetic permeability μ1 of the ferrite material and the magnetic permeability μ2 of the dust-based material have a relationship of μ1:μ2=100:1.

According to the invention set forth in claim 1 , in the choke coil including a core consisting of a first shaft, a second shaft, and a connecting portion, the connecting portion is made of a ferrite material, and the first shaft is made of a dust-based material. Since the second shaft is made of either a ferrite material or a dust-based material, it is possible to use a large current as a choke coil by improving DC superimposition characteristics. Therefore, for example, it is possible to make the transformer smaller, to be able to handle high output, and to improve performance. Furthermore, since the relationship between the magnetic permeability of the ferrite material and the magnetic permeability of the dust-based material is 100:1, the DC superimposition characteristics as a choke coil can be further improved.

In order to solve the above problem, the invention according to claim 2 provides the choke coil according to claim 1 , in which one of the cores includes each of the first shafts and each of the second shafts, which are separate from each other. A total volume v2 that is the sum of the volume v1 of one first shaft that is composed of a shaft and the connecting part and that constitutes one of the cores, and the volume of two second shafts that constitute the core, and The relationship between the volume v3 of the connecting portion and the connecting portion is configured to be v1:v2:v3=1:1.3 or more and 1.4 or less:2.6 or more and 2.8 or less.

According to the invention set forth in claim 2 , in addition to the effect of the invention set forth in claim 1 , one core is made up of mutually separate first shafts, second shafts, and connection parts, The relationship between the total volume of the volume of one first axis constituting one core, the volume of two second axes constituting the core, and the volume of the connection part constituting the core is 1 : 1.3 or more and 1.4 or less: 2.6 or more and 2.8 or less, so the DC superimposition characteristics as a choke coil can be further improved.

In order to solve the above problem, the invention according to claim 3 provides a choke coil according to claim 1 or 2 , in which the bobbin is connected to a body part around which the coil is wound, and a body part around which the coil is wound. flanges at both ends of the body that define a range of the body to be wound, one of the flanges and the body being integrally molded, and the other flange forming the coil with respect to the body. and a structure that is connected to the body after winding.

According to the invention set forth in claim 3 , in addition to the effect of the invention set forth in claim 1 or claim 2 , one flange constituting the bobbin and the body of the bobbin are integrally molded, and the other flange and the body of the bobbin are integrally formed. Since the flange is connected to the body after the coil is wound around the body, the coil can be easily wound around the bobbin regardless of whether the cross section of the winding is circular or square. .

In order to solve the above problem, the invention according to claim 4 provides a choke coil according to claim 1 or 2 , in which the bobbin is connected to a body portion around which the coil is wound, and a body portion around which the coil is wound. flanges at both ends of the body defining a winding range; a first external terminal portion to which a winding having a circular cross section is attached; and a second external terminal portion to which a winding having a rectangular cross section is attached. and a second external terminal section provided side by side with the first external terminal section.

According to the invention set forth in claim 4 , in addition to the effect of the invention set forth in claim 1 or claim 2 , since the second external terminal section is provided alongside the first external terminal section, a different Cost reduction can be achieved by standardizing parts for windings having cross-sectional shapes.

According to the present invention , in a choke coil having a core including a first shaft, a second shaft, and a connecting portion, the connecting portion is made of a ferrite material, the first shaft is made of a dust-based material, The second shaft is made of either a ferrite material or a dust-based material.

Therefore, it becomes possible to use a large current as a choke coil by improving DC superimposition characteristics. This makes it possible, for example, to reduce the size of the transformer, support high output, and improve performance. Furthermore, since the relationship between the magnetic permeability of the ferrite material and the magnetic permeability of the dust-based material is 100:1, the DC superimposition characteristics as a choke coil can be further improved.

1 is an external perspective view showing the structure of a choke coil according to a first embodiment, (a) is an external perspective view showing the structure of a core used in the choke coil, and (b) is an overall structure of the choke coil. FIG. 1 is an external perspective view showing the structure of a bobbin used in the choke coil of the first embodiment, (a) is an external upper perspective view showing the structure of one bobbin, and (b) is a structure of one bobbin. FIG. FIG. 2 is an exploded perspective view showing the structure of the choke coil of the first embodiment. FIG. 7 is a diagram showing the structure of a choke coil according to a second embodiment, in which (a) is an external perspective view showing the overall structure of the choke coil, and (b) is an exploded view showing the structure of the choke coil. FIG. 6 is a diagram showing the structure of a bobbin used in a choke coil according to a second embodiment, in which (a) is an external perspective view showing the structure when a set of the bobbins is combined, and (b) is a perspective view of the structure of one bobbin. FIG. 3B is an upper perspective view of the outer appearance showing the structure of one bobbin, and FIG. FIG. 3 is a diagram showing the effects of the choke coil of the first embodiment and the choke coil of the second embodiment, in which (a) is an equivalent circuit of a conventional choke coil, and (b) is an equivalent circuit of the choke coil of the first embodiment and the choke coil of the second embodiment. FIG. 7C is an equivalent circuit of each of the choke coils of the second embodiment, and (c) is a drive current-inductance characteristic diagram of each of the choke coils of the first embodiment and the choke coil of the second embodiment. It is a figure which shows the structure of the choke coil of 3rd Embodiment, (a) is an external perspective view which shows the structure of the said choke coil as a whole, (b) is an exploded view which shows the structure of the said choke coil. It is a figure which shows the structure of the choke coil of 4th Embodiment, (a) is an external perspective view which shows the structure of the said choke coil as a whole, (b) is an exploded view which shows the structure of the said choke coil. FIG. 7 is a drive current-inductance characteristic diagram for each of the choke coil of the third embodiment and the choke coil of the fourth embodiment.

Next, embodiments of the present invention will be described based on the drawings. Note that each embodiment described below applies to a choke coil for noise reduction (corresponding to the first embodiment and the second embodiment) or a choke coil for a transformer (corresponding to the third embodiment and the fourth embodiment). This is an embodiment in which the present invention is applied.

(I) First embodiment
First, a choke coil according to a first embodiment of the present invention will be described using FIGS. 1 to 3. Note that FIG. 1 is an external perspective view showing the structure of the choke coil of the first embodiment, FIG. 2 is an external perspective view showing the structure of a bobbin used in the choke coil, and FIG. 3 is an external perspective view showing the structure of the choke coil. FIG.

As shown in FIGS. 1 to 3, in the choke coil CK1 of the first embodiment, there is a core C11 whose appearance is shown in FIG. 1(a), and a core C11 whose appearance is shown in FIG. For example, the cores C12 shown in FIG. In the following description, when describing matters common to the core C11 and the core C12 of the first embodiment, these will be simply referred to as "core C11 etc.".

Here, the material forming each core C11 etc. is determined based on the oscillation frequency of the choke coil CK1 in which the core C11 etc. is used (in other words, the required magnetic permeability of the core C11 etc.) and manufacturing cost. More specifically, for example, a ferrite material is used.

As shown in an external perspective view in FIG. 1(a), the core C11 of the first embodiment has a flat top surface 5, a winding shaft 1 and a winding shaft 2 each having a columnar shape, and a common shaft 3 and a common shaft. 4 and are integrally formed. On the other hand, the core C12 of the first embodiment also has the same shape as the core C11 and is formed by integral molding, and specifically includes a flat top surface 5C, a columnar winding shaft 1C, and The winding shaft 2C, the common shaft 3C, and the common shaft 4C are integrally formed. As shown in FIGS. 1 and 3, the corresponding axes of the core C11, etc. (i.e., the respective end faces of the winding shaft 1 and the winding shaft 2, the common shaft 3 and the common shaft 4 shown in FIG. 1, and the core C12) The core C11 and the core C12 are combined vertically, for example, so that the end surfaces of the corresponding winding shafts 1C, 2C, and common shafts 3C and 4C face each other, so that the choke of the first embodiment Used for coil CK1.

In addition, in the above-mentioned structure, the winding shaft 1, the winding shaft 2, the winding shaft 1C, and the winding shaft 2C correspond to an example of the "first shaft" of the present invention, and the common shaft 3, the common shaft 4, the common shaft 3C, and the common shaft The shaft 4C corresponds to an example of the "second shaft" of the present invention, and the top surface 5 and the top surface 5C correspond to an example of the "connection part" of the present invention.

In the core C11 of the first embodiment, the positions of the common shaft 3 and the common shaft 4 are line-symmetrical with the line segment connecting the positions of the central axes of the winding shaft 1 and the winding shaft 2 as an axis of symmetry ( That is, they are formed at positions spaced apart from the line segment in mutually opposite directions. In other words, as shown in FIGS. 1 to 3, the common shaft 3 and the common shaft 4 and the winding shaft 1 and the winding shaft 2 have a cross shape when viewed from above (that is, a cross shape when the top surface 5 is viewed from above). diagonally across the book). On the other hand, also in the core C12 of the first embodiment, the positions of the common shaft 3C and the common shaft 4C are line-symmetrical with the line segment connecting the positions of the central axes of the winding shaft 1C and the winding shaft 2C as the axis of symmetry. It is formed to be. That is, as shown in FIGS. 1 to 3, the common shaft 3C and the common shaft 4C, and the winding shaft 1C and the winding shaft 2C are cross-shaped in plan view (i.e., two cross-shaped when the top surface 5C is viewed in plan). diagonally). Note that the positions of the common shaft 3 and the common shaft 4 in the core C11 etc. of the first embodiment in the planar view are not limited to the positions illustrated in FIGS. 1 to 3, and the positions of the winding shaft 1 and the winding shaft 2 In addition, if the coils shown in FIGS. 1 to 3 can be wound around the winding shaft 1C and the winding shaft 2C by the required number of turns, the cross-shaped shape in plan view in the range of the top surface 5 and the range of the top surface 5C is provided. Any position is acceptable.

Next, when the core C11 and the core C12 of the first embodiment are used in the choke coil CK1 while facing each other, as shown in FIG. 4T and the end surface 4CT of the common axis 4C of the core C12 opposite to the top surface 5C, the lengths of the common shaft 4 and the common shaft 4C are adjusted so that a gap G4 is provided between is shorter than the respective lengths of the winding shaft 1 and the winding shaft 1C and the winding shaft 2 and the winding shaft 2C. Similarly, between an end surface 3T of the common axis 3 of the core C11 opposite to the top surface 5 and an end surface 3CT of the common axis 3C of the core C12 opposite to the top surface 5C, which is opposite to the end surface 3T. The lengths of the common shaft 3 and the common shaft 3C are shorter than the respective lengths of the winding shaft 1 and the winding shaft 1C and the winding shaft 2 and the winding shaft 2C so that a gap G3 is also provided. In the core C11 and the core C12 of the first embodiment, the length of the gap G3 and the gap G4 in the central axis direction of the common axis 4 and the common axis 4C, and the common axis 3 and the common axis 3C, respectively (i.e., the length of the gap G3 and the length of the gap G4) are set in advance in accordance with the size of the normal mode inductance that the choke coil CK1 of the first embodiment should have. The relationship between the length of the gap and the corresponding normal mode inductance at this time will be explained later using FIG. 6 as an experimental result.

On the other hand, the shape of the cross section of the winding shaft 1 and the winding shaft 2 in the first embodiment is circular, oval, or rectangular because the coil is wound as described later, but the shape is common to the first embodiment. The shape of the cross section of the shaft 3 and the common shaft 4 can be freely changed, for example, to a square or an ellipse, depending on the installation position, etc., as long as the common shaft 3 and the common shaft 4 are the same. Further, the cross-sectional shapes of the winding shaft 1C and the winding shaft 2C of the first embodiment are also circular, oval, or rectangular because the coils are wound as described later, but they are common to the first embodiment. The shape of the cross section of the shaft 3C and the common shaft 4C can be freely changed to, for example, a square or an ellipse depending on the installation position, etc., as long as the common shaft 3C and the common shaft 4C are the same.

Next, in the choke coil CK1 of the first embodiment, between the winding shaft 1 and the winding shaft 1C and the coil CL11 wound around them, and between the winding shaft 2 and the winding shaft 2C and the coil CL12 wound around them. The structure of the bobbin of the first embodiment inserted between the two will be explained using FIG. 2.

In the choke coil CK1 of the first embodiment, a bobbin B11 whose structure is illustrated in FIG. 2 and a bobbin B12 (see FIGS. 1 and 3) having the same shape as the bobbin B11 have respective meshing portions that will be described later. They are used in combination so that they interlock with each other. At this time, the bobbin B11 is inserted between the winding shaft 1 and the winding shaft 1C and the coils wound around them, and the bobbin B12 is inserted between the winding shaft 2 and the winding shaft 2C and the coils wound around them. be done. In the following description, when describing matters common to the bobbin B11 and bobbin B12 of the first embodiment, these will be simply referred to as "bobbin B11 etc.".

As shown in an external perspective view in FIG. 2, the bobbin B11 of the first embodiment has a cylindrical body through which the winding shaft 1 and the winding shaft 1C are passed, and around which the coil CL11 is wound. 15, a flange 16 and a flange 17 that define a range in which the coil CL11 is wound in the body 15, a base 10, and the engaging portion 11 for opposing and engaging the bobbin B11 and the bobbin B12. It is formed by integral molding. As described above, the bobbin B12 of the first embodiment also has the same shape as the bobbin B11 shown in FIG. 2 and is formed by integral molding. Further, as the material of the bobbin B11 and the like, for example, resin such as plastic is used. Then, as shown in FIG. 3, the bobbin B11 and the bobbin B12 are combined so that the meshing part 11 of the bobbin B11 and the meshing part 11 of the bobbin B12 face each other and mesh with each other, and the winding shaft 1 is inserted into each body 15. and the winding shaft 1C, the winding shaft 2, and the winding shaft 2C are passed through, and the coil CL11 and the coil CL12 are wound around the respective outer peripheries while their positions are defined by the respective flanges 16 and flange 17. It is used in the choke coil CK1 of the embodiment.

On the other hand, as described above, the core C11 and the core C12 of the first embodiment having the above-described structure are connected to the winding shaft 1, the winding shaft 2, the common shaft 3, and the common shaft 4, respectively, in the choke coil CK1 of the first embodiment. The end faces and the end faces of the winding shaft 1C, the winding shaft 2C, the common shaft 3C, and the common shaft 4C are combined so as to face each other. At this time, the respective end surfaces of the winding shaft 1 and the winding shaft 2 and the respective end surfaces of the winding shaft 1C and the winding shaft 2C are combined so as to butt each other as illustrated in FIG. 1(a). On the other hand, the end surface 3T of the common shaft 3 and the end surface 3CT of the common shaft 3C, and the end surface 4T of the common shaft 4 and the end surface 4CT of the common shaft 4C, respectively, have a gap G3 and a gap G3 as illustrated in FIG. 1(a). They are combined to form G4 respectively.

The winding shaft 1 and the winding shaft 1C facing each other are inserted into the body 15 of the bobbin B11 in which the flange 16 and the flange 17 are formed. A circular winding W11 is wound the required number of turns. Further, the winding shaft 2 and the winding shaft 2C facing each other are inserted into the body 15 of the bobbin B12 on which the flanges 16 and 17 are similarly formed, and a coil CL12 is formed on the outer periphery of the bobbin B12. A winding wire W12 having a circular cross section is wound the required number of turns. Copper is used as the material for these windings W11 and W12, for example. Both ends of the winding W11 facing the outside of the choke coil CK1 are connected to the outside of the choke coil CK1 via an external connection terminal TW11. Further, both ends of the winding W12 facing the outside of the choke coil CK1 are connected to the outside of the choke coil CK1 via an external connection terminal TW12. For these reasons, a plurality of grooves TG into which the external connection terminals TW11 and TW12 are fitted are formed in the base 10 of each of the bobbin B11 and the bobbin B12. Furthermore, it is preferable that the number of turns of the winding W11 in the coil CL11 and the number of turns of the winding W12 in the coil CL12 are mutually the same.

As described above, in the choke coil CK1 of the first embodiment, a gap G3 is provided between the common shaft 3 and the common shaft 3C, and a gap G4 is provided between the common shaft 4 and the common shaft 4C. It is being At this time, when the choke coil CK1 of the first embodiment is used as one of the parts for a vehicle, for example, if the gaps G3 and G4 remain open, the parts may be damaged due to vibrations applied from the outside. It may be affected by changes in characteristics or changes in characteristics. For this reason, as shown in FIG. 3, the buffer member SP may be configured to be sandwiched between positions corresponding to the gaps G3 and G4. Possible materials for the buffer member SP include, for example, plastic and insulating rubber.

Note that the effects of the structure of the choke coil CK1 of the first embodiment described above will be explained later together with the effects of the structure of the choke coil of the second embodiment, which will be described later.

(II) Second embodiment
Next, a choke coil according to a second embodiment, which is another embodiment of the present invention, will be described using FIGS. 4 to 6. 4 is a diagram showing the structure of the choke coil of the second embodiment, FIG. 5 is a diagram showing the structure of a bobbin used in the choke coil, and FIG. 6 is a diagram showing the structure of the choke coil of the first embodiment and the second embodiment. It is a figure showing the effect of each choke coil of an embodiment. Further, in FIGS. 4 and 5, the same members as those of the choke coil CK1 of the first embodiment are given the same member numbers, and detailed explanations are omitted.

Each of the windings W11 and W12 used in the choke coil CK1 of the first embodiment described above had a circular cross-sectional shape. On the other hand, the cross-sectional shape of the winding used in the choke coil of the second embodiment is rectangular. That is, the winding used in the choke coil of the second embodiment is a so-called flat wire. Further, in accordance with this, the shape of the bobbin used in the choke coil of the second embodiment is made into a structure suitable for using a rectangular wire as the winding wire.

As shown in FIGS. 4 and 5, in the choke coil CK2 of the second embodiment, the cores C11 and C12 having the same structure as the core C11 and the core C12 of the choke coil CK1 of the first embodiment are different from each other. They are used in the same manner as the choke coil CK1, for example, by being combined vertically. At this time, as in the case of the choke coil CK1 of the first embodiment, a gap G3 is provided between the common shaft 3 and the common shaft 3C with the buffer member SP in between, and the common shaft 4 and the common shaft 4C, a gap G4 is provided with a buffer member SP in between.

Next, in the choke coil CK2 of the second embodiment, between the winding shaft 1 and the winding shaft 1C and the coil CL21 wound around them (that is, the coil CL21 consisting of the winding W21 which is a rectangular wire), and the winding shaft 2 The structure of the bobbin of the second embodiment, which is inserted between the winding shaft 2C and the coil CL22 (that is, the coil CL22 made of the winding W22, which is a rectangular wire) wound thereon, will be explained with reference to FIG. do.

In the choke coil CK2 of the second embodiment, a bobbin B21, the structure of which is illustrated in FIG. It will be done. At this time, the bobbin B21 is inserted between the winding shaft 1 and the winding shaft 1C and the coil CL21 (winding W21) wound around them, and the bobbin B22 is wound around the winding shaft 2 and the winding shaft 2C. It is inserted between the coil CL22 (winding W22). In addition, in the following description, when explaining matters common to the bobbin B21 and bobbin B22 of the second embodiment, these will be simply referred to as "bobbin B21 etc.".

As shown in external perspective views in FIG. 5, the bobbin B21 of the second embodiment has a cylindrical body through which the winding shaft 1 and the winding shaft 1C are passed, and around which the coil CL21 is wound. 15, the flange 16A and flange 17 that define the range in which the coil CL21 is wound in the body 15, the base 10, and the bobbin B21 and the bobbin B22 are engaged with each other in two upper and lower places to face each other and engage with each other. 11A. At this time, while the body 15 and the flange 17 on the base 10 side are integrally formed, the body 15 and the flange 16A are separate members. Then, after the coil CL21 made of the winding wire W21, which is a rectangular wire, is wound around the body 15, the flange 16A is joined to the body 15, thereby completing the bobbin 21 around which the coil CL21 is wound. ing.

As described above, the bobbin B22 of the second embodiment also has the same structure as the bobbin B21 shown in FIG. Further, as the material of the bobbin B21 and the like, for example, resin such as plastic is used. Then, as shown in FIG. 5, the bobbin B21 and the bobbin B22 are combined so that the meshing portion 11A of the bobbin B21 and the meshing portion 11A of the bobbin B22 face each other and mesh with each other. 1 and the winding shaft 1C, the winding shaft 2 and the winding shaft 2C are passed through, and the coil CL21 and the coil CL22 are wound around the respective outer peripheries while the positions are defined by the respective flanges 16A and flange 17. It is used in the choke coil CK1 of one embodiment.

On the other hand, as described above, in the choke coil CK2 of the second embodiment, the core C11 and the core C12 having the above-described structure are combined in the same manner as the choke coil CK1 of the first embodiment. The winding shaft 1 and the winding shaft 1C facing each other are inserted into the body 15 of the bobbin B21, which includes a flange 16A and a flange 17, and a rectangular wire constituting the coil CL21 is provided on the outside of the bobbin B21. The winding W21 is wound the required number of turns. The opposing winding shaft 2 and winding shaft 2C are similarly inserted into the body 15 of the bobbin B22, which is provided with a flange 16A and a flange 17. The barrel winding W22 is wound the required number of turns. Copper, for example, is also used as the material for these windings W21 and W22. Both ends of the winding W21 facing the outside of the choke coil CK1 are connected to the outside of the choke coil CK2 via an external connection terminal TW21. Further, both ends of the winding W22 facing the outside of the choke coil CK2 are connected to the outside of the choke coil CK2 via an external connection terminal TW22. For these reasons, in the base portion 10 of each of the bobbin B21 and bobbin B22, a flat wire groove TGH into which the external connection terminal TW21 and the external connection terminal TW22 are fitted is provided. It is attached to. Furthermore, it is preferable that the number of turns of the winding W21 in the coil CL21 and the number of turns of the winding W22 in the coil CL22 are mutually the same. Note that the groove TG corresponds to an example of the "first external terminal part" of the present invention, and the flat wire groove TGH corresponds to an example of the "second external terminal part" of the present invention.

As explained above, according to the structure of the choke coil CK1 of the first embodiment and the structure of the choke coil CK2 of the second embodiment, a gap G3 is provided between the common shaft 3 and the common shaft 3C that face each other. A gap G4 is provided between the common shaft 4 and the common shaft 4C, which also face each other. The length of each of the gap G3 and the gap G4 (gap length) is a length corresponding to the size of the normal mode inductance that the choke coil CK1 of the first embodiment or the choke coil CK2 of the second embodiment should have. It is said that Therefore, by being able to generate both normal mode inductance and common mode inductance with one choke coil (choke coil CK1 of the first embodiment or choke coil CK2 of the second embodiment), inductance of each mode can be generated. The choke coil can be made smaller. Therefore, when the structure of the choke coil CK1 of the first embodiment and the choke coil CK2 of the second embodiment are used, for example, as a member of a noise filter, it is possible to make the noise filter smaller, higher output, and higher performance. .

Further, according to the structure of the bobbin B21 and bobbin B22 of the second embodiment, one flange 17 and the body part 15 constituting them are integrally molded, and the other flange 16A is connected to the coil CL21 or the body part 15. Since the coil CL22 is connected to the body 15 after winding (see FIG. 5(b) or 5(c)), even if the winding wire wound around the coil is a wire with a circular cross section, Even if the coil is a rectangular flat wire, the coil can be easily wound around the bobbin B21 or the bobbin B22.

Furthermore, according to the structure of the bobbin B21 and the bobbin B22 of the second embodiment, the groove TG and the dedicated flat groove TGH are provided in the base portion 10 constituting the bobbin, so that parts can be used in common for windings with different cross-sectional shapes. It is possible to realize cost reduction by

Here, experimental results (simulation results) by the inventors of the present application will be shown regarding the effects of providing the gap G3 and the gap G4 described above in the choke coil CK1 of the first embodiment and the choke coil CK2 of the second embodiment. This will be explained in more detail using FIG. 6. In the experiment whose results are shown in FIG. 6, a ferrite material with a magnetic permeability of 7,000 microHenry was used as the material of the core C11 used in the choke coil CK1 of the first embodiment and the choke coil CK2 of the second embodiment. , coil CL11, etc. are each wound 13 times.

That is, when reducing noise over a wide frequency band (several kilohertz to about 30 megahertz) using an input filter circuit including an AC input section IN, fuse F, capacitor CD1, and capacitor CD2 illustrated in FIG. 6(a), When attempting to generate both normal mode inductance and common mode inductance, conventionally, normal mode choke coil CKX1, normal mode choke coil CKX2, and common mode choke coil CKX3 as illustrated in FIG. 6(a) are used. Three choke coils were required. On the other hand, in the case of the choke coil CK1 of the first embodiment or the choke coil CK2 of the second embodiment, by providing the gap G3 and the gap G4, as illustrated in FIG. 6(b), one By simply providing choke coil CK1 or choke coil CK2, a necessary value of normal mode inductance can be obtained in addition to common mode inductance. This makes it possible to downsize the choke coil that can generate two modes of inductance.

The relationship between the respective lengths of the gap G3 and the gap G4 (gap length) and the value of the normal mode inductance obtained therefrom is illustrated in FIG. 6(c) by the inventors of the present application. Experimental results have been obtained. According to the experimental results, it can be seen that when there is a gap G3 and a gap G4, a normal mode inductance with good flatness with respect to the drive current is generated. The maximum normal mode inductance (67.1 microhenries) is obtained when the lengths of the gaps G3 and G4 are each 2 mm. This indicates that a desired normal mode inductance can be obtained by changing the lengths of the gap G3 and the gap G4.

(III) Third embodiment
Next, a choke coil according to a third embodiment, which is still another embodiment of the present invention, will be described using FIG. 7. Note that FIG. 7 is a diagram showing the structure of a choke coil according to the third embodiment. Further, in FIG. 7, the same members as the choke coil CK1 of the first embodiment or the choke coil CK2 of the second embodiment are given the same member numbers, and detailed explanations are omitted.

The core C11 and the like used in the choke coil CK1 of the first embodiment described above are entirely formed of the same material (for example, ferrite material). On the other hand, in the core used in the choke coil of the third embodiment and the choke coil of the fourth embodiment described later, the top surface, the winding axis, and the common axis are formed of multiple types of materials. At this time, the choke coil of the third embodiment and the choke coil of the fourth embodiment are choke coils through which currents controlled by an interleave control method are respectively passed, and are, for example, choke coils used as inductors for transformers. be.

That is, as shown in FIG. 7, in the choke coil CK3 of the third embodiment, a core C31 and a core C32 having the same shape as the core C31 are arranged vertically, for example, so that the end surfaces of their respective shafts face each other. Used in combination. In the following description, when describing matters common to the core C31 and core C32 of the third embodiment, these will be simply referred to as "core C31 etc.".

In particular, as shown in the external perspective view in FIG. 7(b), the core C31 of the third embodiment has a substantially flat top surface 25 and a common shaft 23 and a common shaft 24, each of which is formed integrally. has been formed. On the other hand, as shown in FIG. 7, the core C32 of the third embodiment also has the same shape as the core C31 and is formed by integral molding, and specifically includes a substantially flat top surface 25C, A common shaft 23C and a common shaft 24C each having a columnar shape are integrally formed. At this time, the core C31 and the core C32 are made of the same ferrite material as a whole. Further, the top surface 25 and the top surface 25C have substantially the same shape as the top surface 5 and the top surface 5C of the first embodiment, respectively (excluding the recessed portions where the winding shaft 21 and the winding shaft 22 are abutted, respectively). are doing. On the other hand, the common shaft 23 and the common shaft 24 have the same cross sections as the common shaft 3 and the common shaft 4 of the first embodiment, respectively, but have the same length. It is longer than the shaft 3 and the common shaft 4. Further, the common shaft 23C and the common shaft 24C have the same cross sections as the common shaft 3C and the common shaft 4C of the first embodiment, respectively, but the lengths of the common shaft 3C and longer than the common shaft 4C. Due to these, when the core C31 and the core C32 are used as the choke coil CK3 of the third embodiment, the gaps G3 and G4 of the first embodiment (see FIG. 1, etc.) are not formed as shown in FIG. , the end surface of the common shaft 23 and the end surface of the common shaft 23C abut each other, and the end surface of the common shaft 24 and the end surface of the common shaft 24C also abut each other.

On the other hand, in the choke coil CK3 of the third embodiment, the winding shaft 21 and the winding shaft 22 are separate members from the core C31 and the core C32, and the winding shaft 21 and the winding shaft 22 are made of, for example, a dust-based material. ing. As shown in FIG. 7, the corresponding axes of the core C31 and the like (that is, the end faces of the common shaft 23 and the common shaft 24 shown in FIG. 7, and the corresponding common shafts 23C and 24C of the core C32) In the choke of the third embodiment, the core C31 and the core C32 are combined vertically, for example, so that the winding shaft 21 and the winding shaft 22 are sandwiched between the core C31 and the core C32, so that the end surfaces thereof face each other and the winding shaft 21 and the winding shaft 22 are sandwiched between the core C31 and the core C32. Used for coil CK3. At this time, the positions of the common shafts 23 and 24 and the winding shafts 21 and 22 with respect to the top surface 25 are the same as those of the common shafts 3 and 4 and the winding shafts 1 and 1 of the choke coil CK1 of the first embodiment. This is the same as the position of each of the two with respect to the top surface 5. Further, the positions of the common shaft 23C, the common shaft 24C, the winding shaft 21, and the winding shaft 22 with respect to the top surface 25C are the common shaft 3C, the common shaft 4C, the winding shaft 1C, and the winding shaft 2C of the choke coil CK1 of the first embodiment. It is the same as the position with respect to each top surface 5C. Further, the winding shaft 21 and the winding shaft 22 are sandwiched so as to butt into the recesses of the top surface 25 of the core C31 and the top surface 25C of the core C32, respectively.

Here, the magnetic permeability of the ferrite material that is the material of the core C31 consisting of the top surface 25 and the common shafts 23 and 24, and the core C32 consisting of the top surface 25C and the common shafts 23C and 24C is 2,000 microHenries. On the other hand, the magnetic permeability of the dust-based material that is the material of the winding shaft 21 and the winding shaft 22 is between 20 microhenry and 30 microhenry. That is, the ratio of the magnetic permeability of the ferrite material to the magnetic permeability of the dust-based material is 100:1.

Furthermore, as the choke coil CK3 of the third embodiment, for each volume of the core C31, the core C32, the winding shaft 21, and the winding shaft 22, the volume of one winding shaft 21 or the winding shaft 22 is v1. The combined volume of the common shaft 23 and the common shaft 23C and the common shaft 24 and the common shaft 24C (that is, the volume of the common shaft 23 and the common shaft 23C and the common shaft 24 and the common shaft 24C in the entire choke coil CK3 is When the total) is set as v2, and the volume of either the top surface 25 or the top surface 25C is set as v3, the relationship shown in the following equation (1) is established.
v1: v2: v3 = 1: 1.3 or more and 1.4 or less: 2.6 or more and 2.8 or less (1)
It is to be noted that the above volume ratio is more preferably in the following relationship: v1: v2: v3 = 1:1.3:2.6.

On the other hand, the bobbin used in the choke coil CK3 of the third embodiment has the same configuration as the bobbin B21 and bobbin B22 used in the choke coil CK2 of the second embodiment. A coil CL11 made of a winding W11 is wound around the bobbin B21 on the outside of the body 15, and a winding shaft 21 is passed through the inside of the body 15. On the other hand, a coil CL12 made of a winding W12 is wound around the outside of the body 15 of the bobbin B22, and the winding shaft 22 is passed through the inside of the body 15.

The effects of the structure of the choke coil CK3 of the third embodiment described above will be explained later together with the effects of the structure of the choke coil of the fourth embodiment, which will be described later.

(IV) Fourth embodiment
Finally, a choke coil according to a fourth embodiment, which is still another embodiment of the present invention, will be described with reference to FIGS. 8 and 9. Note that FIG. 8 is a diagram showing the structure of the choke coil of the fourth embodiment, and FIG. 9 is a current-inductance characteristic diagram of each of the choke coil CK3 of the third embodiment and the choke coil of the fourth embodiment. Further, in FIG. 8, the same members as any of the choke coil CK1 of the first embodiment to the choke coil CK3 of the third embodiment are given the same member numbers, and detailed explanations are omitted.

In the choke coil CK3 of the third embodiment described above, the top surface 25, the common shaft 23, and the common shaft 24 are integrally molded using a ferrite material, and the top surface 25C, the common shaft 23C, and the common shaft 24C are made of ferrite. It was molded in one piece using the same material. Furthermore, the winding shaft 21 and the winding shaft 22 are formed as separate parts using a dust-based material. On the other hand, the top surface of the core C4 used in the choke coil of the fourth embodiment is made of a ferrite material, and the winding shaft and the common shaft are both made of a dust-based material.

That is, as shown in FIG. 8, in the choke coil CK4 of the fourth embodiment, the common shafts 33 and 34 made of dust-based material and the winding shaft 21 are provided between the top surface 35 and the top surface 35C made of ferrite material. A core C4 as a choke coil CK4 is formed with the winding shaft 22 sandwiched therebetween. At this time, the shapes of the common shaft 33 and the common shaft 34 are the same as the shapes of the winding shaft 21 and the winding shaft 22, respectively.

On the other hand, the top surface 35 and the top surface 35C have substantially the same shape as the top surface 5 and the top surface 5C of the first embodiment, respectively (the winding shaft 21 and the winding shaft 22 and the common shaft 33 and the common shaft 34 are butted, respectively). (excluding recesses). At this time, the positions of the common shaft 33 and the common shaft 34 and the winding shaft 21 and the winding shaft 22 with respect to the top surface 35 and the top surface 35C are the same as those of the common shaft 3 and the common shaft 4 and the winding shaft of the choke coil CK1 of the first embodiment. 1 and the winding shaft 2 with respect to the top surface 5, or the positions of the common shaft 3C and the common shaft 4C, and the winding shaft 1C and the winding shaft 2C with respect to the top surface 5C. Further, the winding shaft 21, the winding shaft 22, the common shaft 33, and the common shaft 34 are sandwiched so as to butt into the recessed portions of the top surface 35 and the top surface 35C, respectively.

Further, the ratio of the magnetic permeability of the ferrite material that is the material of the top surface 35 and the top surface 35C to the magnetic permeability of the tast-based material that is the material of the winding shaft 21 and the winding shaft 22 and the common shaft 33 and the common shaft 34 is as follows. This is the same as the ratio of the magnetic permeability of the ferrite material and the magnetic permeability of the dust-based material used in the choke coil CK3 of the third embodiment. In addition, the volume of either the winding shaft 21 or the winding shaft 22, the volume of the common shaft 33, and the volume of the common shaft 34 (that is, the volume of the two common shafts), and the volume of the top surface 35 or the top surface The volume ratio of either one of the surfaces 35C is also the same as the volume ratio of the top surface 25 and the like in the choke coil CK3 of the third embodiment.

On the other hand, the bobbin used in the choke coil CK4 of the fourth embodiment has the same configuration as the bobbin B21 and bobbin B22 used in the choke coil CK2 of the second embodiment. A coil CL21 made of a rectangular wire winding W21 is wound around the bobbin B21 on the outside of the body 15, and the winding shaft 21 is passed through the inside of the body 15. On the other hand, a coil CL22 made of a rectangular wire winding W32 is wound on the outside of the body 15 of the bobbin B22, and the winding shaft 22 is passed through the inside of the body 15.

As explained above, according to the structure of the choke coil CK3 of the third embodiment and the structure of the choke coil CK4 of the fourth embodiment, the top surface 25 and the top surface 25C and the top surface 35 and the top surface 35C are made of ferrite material. The winding shaft 21 and the winding shaft 22 are made of a dust-based material, the common shaft 24C and the common shaft 24 of the third embodiment, and the common shaft 23C and the common shaft 23 are made of a ferrite material, while the common shaft of the fourth embodiment is made of a ferrite material. Since the shaft 33 and the common shaft 34 are made of a dust-based material, it is possible to use a large current as a choke coil by improving DC superimposition characteristics. Therefore, for example, when the choke coil CK3 of the third embodiment and the choke coil CK4 of the fourth embodiment are used as a member of a transformer, the transformer can be made smaller, capable of high output, and improved in performance.

Furthermore, since the relationship between the magnetic permeability of the ferrite material and the magnetic permeability of the dust-based material used in the choke coil CK3 of the third embodiment or the choke coil CK4 of the fourth embodiment is 100:1, the choke coil CK3 of the third embodiment or the choke coil CK4 of the fourth embodiment has a relationship of 100:1. The DC superimposition characteristics of can be further improved.

Furthermore, in the choke coil CK3 of the third embodiment, the volume v1 of either one of the winding shafts 21 or 22 is combined with the volumes of the common shafts 23 and 23C, and the common shafts 24 and 24C. The ratio of the volume v2 and the volume v3 of either the top surface 25 or the top surface 25C is v1:v2:v3=1:1.3 or more and 1.4 or less:2.6 or more and 2.8 or less. Therefore, the DC superimposition characteristics as a choke coil can be further improved. Note that this point is the same in the choke coil CK4 of the fourth embodiment.

Regarding the relationship between the differences in the materials of the top surface 25 and the like used in the choke coil CK3 of the third embodiment and the DC superimposition characteristics obtained therefrom, the inventors of the present application have shown experimental results illustrated in FIG. 9. is obtained. In FIG. 9, the graph indicated by the "□" mark shows the drive current and inductance when using the choke coil CK3 of the third embodiment (the thickness of the top surface 25 and the top surface 25C is 9.6 mm). The graph indicated by the "▲" mark shows the relationship between the drive current and the inductance when the thickness of the top surface 25 and the top surface 25C is half of that of the choke coil CK3 of the third embodiment. It shows a relationship. Furthermore, the graph indicated by the mark "◆" shows the relationship between the drive current and inductance when using the choke coil CK4 of the fourth embodiment (the thickness of the top surface 35 and the top surface 35C is 9.6 mm). The graph indicated by the "●" mark is a comparative example in which the entire core (including the top surface, common shaft, and winding shaft) constituting the choke coil is made of dust-based material, and the thickness of the top surface is It shows the relationship between drive current and inductance when the value is the same as in the graph indicated by the "▲" mark. According to the experimental results shown in FIG. 9, the structure of the choke coil CK4 of the fourth embodiment is the most desirable in terms of desired DC superimposition characteristics, and the structure of the choke coil CK3 of the third embodiment is the second most desirable. I understand. On the other hand, if all the cores constituting the choke coil are made of dust-based material, the desired DC superposition characteristics cannot be obtained due to a decrease in inductance value when compared with the same number of windings. I understand.

As explained above, the present invention can be used in the field of choke coils, and especially when applied to the field of choke coils aimed at miniaturization and high performance, particularly remarkable effects can be obtained. .

1, 1C, 2, 2C, 21, 22 Winding shaft 3, 3C, 4, 4C, 23, 23C, 24, 24C, 33, 34 Common shaft 3T, 4T, 3CT, 4CT End face 5, 5C, 25, 25C, 35, 35C Top surface 10 Base 11, 11A Engagement part 15 Body 16, 16A, 17 Flange F Fuse CK1, CK2, CK3, CK4 Choke coil C11, C12, C31, C32, C4 Core G3, G4 Gap CL11, CL12, CL21, CL22 Coil B11, B12, B21, B22 Bobbin W11, W12, W21, W22 Winding TW11, TW12, TW21, TW22 External connection terminal TG Groove SP Buffer member TGH Flat wire groove IN AC input section CD1, CD2 Capacitor CKX1 , CKX2 Normal mode choke coil CKX3 Common mode choke coil

Claims (4)

two first shafts each having a coil wound thereon via an insulating bobbin, the first shafts being arranged parallel to each other and facing each other, each having a columnar shape;
two second axes arranged parallel to each other and facing each other, each having a columnar shape, and around which no coil is wound, the second axis being parallel to the first axis;
The end of each of the first shafts and the end of each of the second shafts corresponding to the end are connected by a line connecting the first shafts and a line connecting the second shafts. a plate-shaped connection part that connects to cross each other and allows magnetic flux generated by the current flowing through each of the coils to pass through the first axis and the second axis;
Two cores each with
the two bobbins, each of which the first shaft is passed through inside and the coil is wound outside;
the coils respectively wound around the first shaft via the bobbin;
Equipped with
the connecting portion is made of ferrite material,
Each of the first shafts is made of a dust-based material,
Either each of the second shafts is made of the ferrite material, or both of the second shafts are made of the dust-based material,
The relationship between the magnetic permeability μ1 of the ferrite material and the magnetic permeability μ2 of the dust-based material is,
A choke coil characterized in that μ1:μ2=100:1 . The choke coil according to claim 1,
One of the cores includes each of the first shafts, each of the second shafts, and the connection portion that are separate from each other,
A total volume v2 of the volume v1 of one first axis constituting one core, a volume v2 of two second axes constituting the core, and a volume v3 of the connection part constituting the core. The relationship between
v1: v2: v3 = 1: 1.3 or more and 1.4 or less: 2.6 or more and 2.8 or less
A choke coil characterized by : The choke coil according to claim 1 or 2,
The bobbin is
a body portion around which the coil is wound;
flanges at both ends of the body defining a range of the body around which the coil is wound;
Equipped with
one of the flange and the body portion are integrally molded;
A choke coil characterized in that the other flange is connected to the body after the coil is wound around the body . The choke coil according to claim 1 or 2 ,
The bobbin is
a body portion around which the coil is wound;
flanges at both ends of the body defining a range around which the coil is wound;
a first external terminal portion to which a winding having a circular cross section is attached;
a second external terminal portion to which a winding having a rectangular cross section is attached, the second external terminal portion being provided alongside the first external terminal portion;
A choke coil characterized by comprising :

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