JP2002252126A - Inductance element and snubber circuit using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of the joint part being separated, when an impact is given in the conventional method for fixing a magnetic thin band in an inductance element and the inductance is reduced because the magnetic thin band becomes loose from winding. SOLUTION: This inductance element is comprised of a coil part, in which a winding whose number of windings (N) per 10 mm in length is >=20 and <=500, is formed in an insulator bobbin having flanges on both ends, and a single layer or multiple layers of magnetic thin band whose thickness is >=4 μm and <=50 μm and width is >=1 mm and <=40 mm, and it is provided with a core of closed magnetic circuit, in which at least a part is arranged inside the insulator bobbin and an insulation tape for fixing the magnetic thin band. The ratio (N/n) of the number of windings (N) in the coil to the number of layers (n) in the magnetic thin band is >=20 and <=500, and an angle formed by the insulation tape in the lengthwise direction and the magnetic thin band in the lengthwise direction is 60 to 120 degrees.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an inductance element used for a snubber circuit and a delay element of a switching power supply, and a snubber circuit using the same.

[0002]

2. Description of the Related Art Inductance elements are used in various electric circuits. For example, in a switching power supply such as an RCC system, a MOS-F which is a switching element is used.
An inductance element (saturable inductor) is used as a current delay element that delays the gate signal of ET. This current delay element causes the snubber capacitor to function as a resonance capacitor and causes the MOS-FET to perform zero volt switching.

As a conventional inductance element, for example, an element having a toroidal core formed by winding or laminating a soft magnetic alloy ribbon is mainly used. When such an inductance element is applied to the current delay element as described above, a predetermined characteristic can be obtained by winding an insulated wire (winding) a plurality of times around a toroidal core having a closed magnetic circuit structure. I have.

[0004] An inductance element having a toroidal core is advantageous in obtaining inductance based on its closed magnetic circuit structure. However, in the case of a toroidal core made of a magnetic ribbon, a wire is wound around an insulating bobbin in advance, like a sintered core made of a ferrite sintered body, and the divided sintered cores are joined together to form a closed magnetic circuit. The configuration of forming cannot be easily applied.

For this reason, when a conventional toroidal core made of a magnetic ribbon is used, an inductance element is generally formed by directly winding a winding on the toroidal core. However, with such a structure, the work efficiency of winding to the toroidal core is low, and it is difficult to automate the winding process. As a result, the manufacturing cost of the inductance device is increased.

In order to improve the work efficiency of the winding and to automate the winding, recently, a structure in which a winding is applied to a bobbin and a magnetic ribbon is arranged in the bobbin has been proposed. Has been proposed.

[0007]

As described above, by forming a winding on a bobbin and then arranging a magnetic ribbon in the bobbin, the working efficiency of the winding can be improved and the winding can be improved. Automation is possible.

However, when a closed magnetic circuit structure is formed in the above-described inductance element, after inserting the magnetic ribbon into the bobbin, both ends of the magnetic ribbon are bent outside the bobbin and overlapped. It was fixed with insulating tape. In this case, the insulating tape may be peeled off due to the stress that tends to return the magnetic ribbon.

In order to fix the magnetic ribbon more securely, the both ends of the magnetic ribbon are bent outside the bobbin as shown in FIG. In some cases, the band is wound around the whole of the band including the magnetic ribbon and the bobbin in the same direction as the longitudinal direction of the band. However, when the insulating tape is wound in the same direction as the longitudinal direction of the magnetic ribbon, automation by a machine is difficult, and when the bobbin has a flange, the distance (S) between the magnetic ribbon and the winding is determined by the flange. And the inductance characteristics cannot be improved.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an inductance element in which a magnetic ribbon is hardly detached by an impact or the like and whose characteristics are improved. Another object of the present invention is to provide a snubber circuit having excellent characteristics and reliability by using such an inductance element.

[0011]

According to the inductance element of the present invention, the number of turns (N) per 10 mm length is 20 or more and 5 or more.
And a single-layer or plural-layer magnetic ribbon having a thickness of 4 μm or more and 50 μm or less and a width of 1 mm or more and 40 mm or less. An inductance element comprising: a core portion having a closed magnetic circuit structure disposed inside the insulator bobbin; and an insulating tape for fixing the magnetic ribbon, wherein the number of turns (N) of the coil and the magnetic thin film The ratio (N / n) to the number of layers (n) in the belt is 20 or more and 500 or less,
Further, an angle formed between the longitudinal direction of the insulating tape and the longitudinal direction of the magnetic ribbon is 60 degrees to 120 degrees.

By setting the angle between the longitudinal direction of the insulating tape and the longitudinal direction of the magnetic ribbon within the range of 60 to 120 degrees, the distance between the magnetic ribbon and the winding is reduced to improve the inductance characteristics. Can be. Further, since the longitudinal direction of the insulating tape and the longitudinal direction of the magnetic ribbon are not the same, it is possible to assemble the inductance element by a machine. The angle between the longitudinal direction of the insulating tape and the longitudinal direction of the magnetic ribbon is more preferably 90 degrees.

It is preferable that the insulating tape is formed so as to make at least one round around the insulating bobbin. By forming at least one round around the insulating bobbin, peeling of the insulating tape can be suppressed, and the distance between the magnetic ribbon fixed by the insulating tape and the winding can be shortened, and the inductance can be reduced. The characteristics can be improved.

Preferably, the width (W _t ) of the insulating tape is 0.4 or more and 1.0 or less of the length (L _b ) of the winding portion of the insulating bobbin. By setting the width of the insulating tape within the above range, the magnetic ribbon can be securely fixed, and wrinkles and the like can be suppressed from being generated in the insulating tape.

It is preferable that the distance between the winding at the center of the winding portion of the insulating bobbin and the magnetic ribbon be within 1 mm. Preferably, the winding and the magnetic ribbon are in contact with at least one or more locations. By setting the distance at least at the center of the winding portion to within 1 mm, the inductance characteristics can be improved. Also,
By bringing the winding into contact with the magnetic ribbon, the inductance characteristics can be further improved.

The height of the flange of the insulating bobbin is preferably higher than the height (thickness) of the coil portion. More preferably, the height is 1.1 times or more higher than the height of the coil portion.
By increasing the height of the flange in this way, it is possible to prevent the winding wound around the insulating bobbin from falling off the insulating bobbin. If the flange is too large, the size of the element is increased.
1-2 times is a more preferable range. When the thickness of the coil portion is not uniform, the thickest (highest) portion is used as a reference.

The magnetic ribbon used in the inductance element of the present invention is preferably a magnetic ribbon that has not been heat-treated. By using the magnetic ribbon that has not been subjected to the heat treatment, for example, when the magnetic ribbon is processed into an annular shape, it is possible to suppress the occurrence of cracks and the like in the curved portion.

Further, the snubber circuit of the present invention is one in which the inductance element having excellent workability and characteristics as described above is connected to the drive circuit of the switching element.
By using such an inductance element, circuit efficiency and the like can be improved.

[0019]

Embodiments of the present invention will be described below. FIG. 1 is an external view showing an inductance element 1 of the present invention. FIG. 2 is a sectional view of the inductance element 1 shown in FIG.

The insulating bobbin 2 is formed with a hollow portion whose both ends are open, and a flange 3 is provided at each end to prevent the winding from falling off. Further, a lead 4 is provided below the insulating bobbin 2. A winding 6 whose both ends are electrically connected to the lead 4 is wound around the winding 5 of the insulating bobbin 2 to form a coil.

In the hollow portion of the insulating bobbin 2, a magnetic ribbon 7 is provided.
Are inserted, and both end portions of the magnetic ribbon 7 protruding from the hollow portion are overlapped on the winding 6 to form a closed magnetic circuit structure. Furthermore, the winding part 5 of the insulating bobbin 2 provided with the magnetic ribbon 7 forming the closed magnetic circuit structure has an angle between the longitudinal direction of the magnetic ribbon 7 and the longitudinal direction of the insulating tape 8 of 60 degrees or more.
An insulating tape 8 is wound so as to be within a range of 120 degrees to fix the magnetic ribbon 7.

The longitudinal direction of the magnetic ribbon 7 is the direction indicated by the arrow 9 shown in FIG. 3, and the longitudinal direction of the insulating tape 8 is the direction indicated by the arrow 10 in FIG. The angle between them is represented by θ in FIG.

In the present invention, the insulating tape 8 is wound so that the angle θ between the longitudinal direction of the magnetic ribbon 7 and the longitudinal direction of the insulating tape 8 is in the range of 60 to 120 degrees.
As compared with the case where the magnetic tape is wound in the same direction (θ = 0 °) as the longitudinal direction of the magnetic ribbon, it is possible to prevent the insulating tape from coming off due to impact or the like, and to prevent the overlapping portion of the magnetic ribbon from being moved. .

By setting the angle θ in the range of 60 to 120 degrees, the magnetic ribbon 7 can be fixed close to the winding 6, and the inductance characteristics can be improved. In particular, when the flange 3 is formed on the insulating bobbin 2, the magnetic ribbon 7 is wound over the winding 6 more than the height of the flange 3.
, And the inductance characteristic is significantly improved.

Further, it has been difficult to automate the machine by winding the insulating tape in the same direction as the longitudinal direction of the magnetic ribbon. However, when the insulating tape is wound at the angle θ as described above, the automation by the machine is also required. It becomes possible. On the other hand, when the angle θ is 6
If it is less than 0 degrees or more than 120 degrees, there are problems that wrinkles are likely to be generated in the insulating tape and it is difficult to shorten the distance between the winding and the magnetic ribbon.

The angle θ between the longitudinal direction of the magnetic ribbon 7 and the longitudinal direction of the insulating tape 8 is preferably 90 degrees. By setting the angle θ to 90 degrees, wrinkling of the insulating tape 8 can be suppressed, and the magnetic ribbon 7 can be more reliably fixed.

It is preferable that the insulating tape 8 is wound around the winding part 5 at least once. At least one
By causing the magnetic ribbon 7 to rotate, the magnetic ribbon 7 can be reliably fixed, and the overlapping portion of the magnetic ribbon 7 can be prevented from coming off. More preferably, at least 1.5 turns, both ends of the insulating tape 8 can be overlapped,
It can be fixed more reliably.

FIG. 4 shows an enlarged cross section of the inductance element 1 of the present invention. In such a case, the width (W _t ) of the insulating tape 8 is equal to the length (L
Preferably, _b ) is 0.4 or more and 1.0 or less. If the width (W _t ) of the insulating tape 8 is less than 0.4 of the length (L _b ) of the winding portion 5, the range in which the magnetic ribbon 7 can be fixed becomes narrow, and the strength of the insulating tape 8 is insufficient. To do
The overlapping portion of the magnetic ribbon 7 is likely to come off. Further, when the width (W _t ) of the insulating tape 8 exceeds 1.0 of the length (L _b ) of the winding portion 5, the insulating tape 8 is insulated because the both end portions are caught on the flange 3. Tape 8
Wrinkles are formed, and the adhesion between the winding portion 5 and the magnetic ribbon 7 is reduced, which causes a decrease in inductance characteristics. It is preferable that the width (W _t ) of the insulating tape 8 is not less than 0.5 and not more than 0.8 of the length (L _b ) of the winding portion 5 from the viewpoint of manufacturability, strength and the like.

In the present invention, the shortest distance (S) between the winding 6 and the magnetic ribbon 7 at the center of the winding 5 is preferably within 1 mm. By setting the shortest distance (S) at least at the center to within 1 mm, sufficient inductance characteristics can be obtained. In the present invention, the shortest distance (S) between the winding 6 and the magnetic ribbon 7 is as small as possible.
It is more preferable that the winding 6 and the magnetic ribbon 7 are in contact with each other.

The height (H _b ) of the flange 3 formed at both ends of the insulating bobbin 2 is preferably higher than the height of the coil portion so that the winding 6 does not fall off the insulating bobbin 2.
In the present invention, since the angle θ between the longitudinal direction of the magnetic ribbon 7 and the longitudinal direction of the insulating tape 8 is set to 60 degrees to 120 degrees, even if the flange 3 having such a height is formed, the winding 6 The shortest distance (S) between the flange 3 and the magnetic ribbon 7 can be equal to or less than the height ( _Hb ) of the flange 3.

In the present invention, the flange 3 does not necessarily need to be provided so as to make one round around the outer periphery of the insulating bobbin 2.
For example, as shown in FIG. 5, the flanges 3 may be provided only on both side ends of the insulating bobbin 2, and the portion where the magnetic ribbon is arranged may have no flange. In the insulating bobbin having such a shape, the gap between the magnetic ribbon and the winding is not widened by the flange, and the inductance is easily improved.

In the present invention, the magnetic ribbon may be fixed using, for example, a U-shaped or U-shaped clip instead of the insulating tape. In this case, as in the case of using the insulating tape, the angle formed by the opening of the U-shaped or U-shaped clip with the longitudinal direction of the magnetic ribbon is 60 to 120 degrees, preferably 90 degrees. It is better to do.

Next, the coil portion of the inductance element of the present invention will be described in detail. The winding 6 is, for example, an insulated conductor. Such a winding 6 has a coil length of 10
The bobbin 2 is wound around the winding portion 5 such that the number of turns (N) per mm is 20 or more and 500 or less.

In such a coil, a length of 10 mm
If the number of turns per unit (N) is less than 20, sufficient magnetic properties cannot be obtained when a magnetic ribbon having a very small cross-sectional area is used as the core. On the other hand, if the number of turns (N) per 10 mm length exceeds 500, the density of the windings 6 becomes too large, the stray capacitance between the windings 6 increases, and the function as an inductance element becomes saturated, and the efficiency increases. No improvement can be seen. In addition, since the number of turns of the coil is large, the thickness of the portion where the coil is wound becomes large, and it is difficult to reduce the size of the element.

The magnetic ribbon 7 has a thickness of 4 μm to 50 μm.
m and a width of 1 mm or more and 40 mm or less.
If the thickness of the magnetic ribbon 7 exceeds 50 μm, eddy current loss and the like increase, and loss particularly in a high frequency region increases. On the other hand, when the thickness of the magnetic ribbon 7 is less than 4 μm, the productivity is reduced,
There is a possibility that the smoothness of the surface is degraded, and that pinholes and the like increase. The thickness of the magnetic ribbon 7 is 10 μm or more and 30
It is more preferable that the thickness be not more than μm.

Further, by setting the width of the magnetic ribbon 7 within the above-mentioned range, problems such as bending at the time of bobbin insertion are reduced, the handling efficiency is improved, the production efficiency is improved, and the high-frequency loss is further reduced. An inductance element can be obtained.

According to the present invention, the magnetic ribbon 7 is effective enough even with a single layer.
It is also possible to laminate them. When a plurality of layers of the magnetic ribbon 7 are used, the shape of each magnetic ribbon 7 is set within the above-mentioned numerical range.

In the inductance element according to the present invention, the ratio (N / n) of the number of turns (N) per 10 mm length of the coil to the number of laminations (n) of the magnetic ribbon 7 is 20 or more and 5 or more.
00 or less. By setting the relationship between the number of turns (N) of the coil and the number of laminations (n) of the magnetic ribbon 7 within the above-described range of the N / n ratio, the magnetic ribbon 7 having a thickness of 4 μm or more and 50 μm or less can be obtained. For example, when a single layer is used, sufficient magnetic characteristics can be obtained.

That is, when the N / n ratio is less than 20,
In the inductance element of the present invention having the magnetic ribbon 7 having a small cross-sectional area as a core, sufficient magnetic characteristics cannot be secured. On the other hand, if the N / n ratio exceeds 500, the density of the windings 6 increases and lap winding is required, and the stray capacitance between the windings 6 increases, and the function of the element is saturated.

The number (n) of stacked magnetic ribbons 7 is N
The ratio is not particularly limited as long as it satisfies the range of the / n ratio. However, it is preferable to use three layers or less in order to reduce the size of the inductance element.

The material of the magnetic ribbon 7 used in the present invention includes a crystalline soft magnetic alloy, an amorphous soft magnetic alloy, and a soft magnetic alloy having a microcrystalline structure (hereinafter, referred to as a microcrystalline soft magnetic alloy). Various soft magnetic materials can be applied. Among them, in the present invention, it is particularly preferable to use an amorphous soft magnetic alloy or a microcrystalline soft magnetic alloy. Examples of the crystalline soft magnetic alloy include a permalloy. Specifically, 55 to 85% by mass of Ni and 7% of Mo
It is preferable to use a permalloy alloy containing not more than 2% by mass of Cu, 2 to 27% by mass of Cu, and the balance substantially consisting of Fe. The magnetic ribbon 7 made of a permalloy is obtained, for example, by forming an alloy thin plate by a melting method, performing hot rolling and cold rolling on the alloy thin plate to form a ribbon having a predetermined thickness (4 to 50 μm). Can be The magnetic properties of the obtained ribbon are adjusted by heat treatment in a magnetic field.

When the magnetic ribbon 7 is made of an amorphous soft magnetic alloy, a Co-based amorphous alloy, a Fe-based amorphous alloy,
-It is preferable to use a Ni-based amorphous alloy or the like. Co
As an amorphous alloy of a base group and a Fe group, a general formula: (M _1-a M ′ _a ) _100-x X _x (where M is at least one selected from Fe and Co)
M ′ is Ti, V, Cr, Mn, Ni, C
u, Zr, Nb, Mo, Ta, W, etc., at least one element selected from X, X represents at least one element selected from B, Si, C, P, etc., and a and x each represent 0 ≦ a ≦ 0.5, 10 ≦ x ≦ 35 at%) are exemplified.

Fe and Co as M elements have a magnetic flux density,
The composition ratio is adjusted in accordance with required magnetic properties such as iron loss and sensitivity to minute current. The M 'element is an element added for the purpose of controlling thermal stability, corrosion resistance, crystallization temperature and the like, and it is particularly preferable to use Cr, Mn, Zr, Nb, Mo, or the like. Element X is an essential element for obtaining an amorphous alloy. B is an element effective for making the alloy amorphous, and Si is an element effective for promoting the formation of an amorphous phase and increasing the crystallization temperature.

[0044] As the Fe-Ni based amorphous alloys, the general _{formula: (Ni 1-b Fe b} ) 100-yzw M "y Si z B w ( wherein, M" is V, Cr, Mn, Co, Nb, Mo, T
a, W, at least one element selected from Zr and the like, and b, y, z and w each represent 0.2 ≦ b ≦ 0.
5,005 ≦ y ≦ 10 at%, 4 ≦ z ≦ 12 at%, 5 ≦
(the number satisfies w ≦ 20 at%, 15 ≦ z + w ≦ 30 at%).

The Fe—Ni-based amorphous alloy should be manufactured at a lower cost than the above-mentioned Co-based amorphous alloy after obtaining good magnetic properties by using Ni-rich Fe—Ni as a base. Is made possible. The M ″ element is an element added for controlling thermal stability, corrosion resistance, and crystallization temperature, and it is particularly preferable to use Cr, Mn, Co, Nb, or the like.

The magnetic ribbon 7 made of an amorphous soft magnetic alloy is
For example, it is produced by a liquid quenching method. Specifically, it can be obtained by rapidly cooling an alloy material adjusted to a predetermined composition ratio from a molten state at a cooling rate of 10 ⁵ ° C / sec or more. By such a liquid quenching method, an amorphous alloy ribbon having a thickness in the range of 4 to 50 μm can be obtained.

[0047] The microcrystalline soft magnetic alloy be applied to the magnetic ribbons 7, the general _{formula: Fe 100-cdef Cu c A} d Si e B f ( wherein, A is Ti, Zr, Hf, V, Nb, Ta , C
represents at least one element selected from r, Mo, W, Mn, Ni, Co and Al, where c, d, e and f are respectively 0.01 ≦ c ≦ 4 atomic%, 0.01 ≦ d ≦ 10 Atomic%, 10 ≦ e ≦ 25 atomic%, 3 ≦ f ≦ 12 atomic%, 17 ≦
e + f ≦ 30 atomic%), and those having fine crystal grains having an average particle diameter of, for example, 50 nm or less, which are substantially composed of an Fe-based alloy.

Here, Cu is an element effective for improving corrosion resistance, preventing coarsening of crystal grains, and improving soft magnetic properties such as iron loss and magnetic permeability. Element A is an element that is effective for making the crystal grain size uniform, reducing magnetostriction and magnetic anisotropy, and improving magnetic properties against temperature change. The microcrystalline structure preferably has a form in which crystal grains having a grain size of 5 to 30 nm are present in the alloy at a surface kneading ratio of 50 to 90%.

The magnetic ribbon 7 made of an Fe-based microcrystalline soft magnetic alloy is prepared, for example, by preparing an amorphous alloy ribbon by a liquid quenching method, and then setting the temperature in the range of -50 to + 120 ° C. with respect to the crystallization temperature. For 1 minute to 5 hours to precipitate fine crystals, or a method of directly depositing fine crystals by controlling the quenching rate of the liquid quenching method. By performing heat treatment while applying a magnetic field in the width direction of such a microcrystalline soft magnetic alloy ribbon, a predetermined DC squareness ratio can be obtained.

The constituent material of the magnetic ribbon 7 is appropriately selected and used according to the intended use of the magnetic element. For example, to obtain a saturable inductor with high magnetic permeability,
It is preferable to use a Co-based amorphous soft magnetic alloy. For a small smooth choke coil, it is preferable to use an Fe-based microcrystalline soft magnetic alloy, an Fe-based amorphous soft magnetic alloy, or the like. In addition, by using the magnetic ribbon 7 without heat treatment, it is possible to prevent the magnetic ribbon 7 from being embrittled. By preventing the magnetic ribbon 7 from being embrittled, it is possible to suppress the occurrence of cracks and the like in a curved portion (turned portion) of the magnetic ribbon 7 even when the magnetic ribbon 7 is annularly formed to have a closed magnetic circuit structure. it can.

Next, an embodiment of the snubber circuit of the present invention will be described. The snubber circuit of the present invention includes the above-described magnetic element 1 of the present invention, and the magnetic element 1 is used by being connected to a drive circuit of a switching element. FIG. 6 is a circuit diagram showing a configuration example of a self-excited flyback type switching power supply using the snubber circuit of the present invention.

In FIG. 6, a primary winding 14 of a transformer 13 and an FET 15 as a switching element are connected in series between input terminals 11 and 12. The transformer 13 includes a FET 1 as a drive circuit for the FET 15.
5, a gate circuit drive winding 16 is provided. That is, the winding 16 is a positive feedback winding of the transformer 13 wound to cause the FET 15 to self-oscillate. FE
Between the gate circuit of T15 and the winding 16 for FET drive, the magnetic element 1, the resistor 17 and the capacitor 18 of the present invention are provided.
Are connected in series, and these constitute a snubber circuit 19.

The resistor 17 supplies an appropriate drive current to the FET 15 and the capacitor 18 is connected to the FET 1
5 are arbitrarily connected to improve the drive characteristics. It is preferable that each of these is connected in series with the magnetic element 1 of the present invention.

The primary winding 14 of the transformer 13 and the input terminal 1
2, a snubber capacitor 20 for absorbing a surge voltage generated in the primary winding 14 of the transformer 13 is connected in series. Further, a snubber resistor 21 is connected in series with the snubber capacitor 20 to reduce the rate of change di / dt of the charging current i. The transformer 1
The secondary winding 22 side of No. 3 is the same as a conventional switching power supply, and a rectifying element 23 and a capacitor 24 are connected as an output smoothing circuit.

In the switching power supply as described above, the magnetic element 1 according to the present invention effectively functions as a current delay element for delaying the gate signal of the FET 15, and the FET 15 can be satisfactorily switched to zero volts. By using the magnetic element of the present invention, it is possible to prevent damage to the device due to impact or the like, and also possible to reduce surge current of the FET 15 as a switching element, improve power supply efficiency, and the like.

[0056]

Next, embodiments of the present invention will be described with reference to examples. Examples 1 to 5 and Comparative Examples 1 and 2 The diameter of a winding portion (9 mm) of an insulating bobbin (bobbin shape “A”) made of a liquid crystal resin and having a flange only on the side surface as shown in FIG. A coil portion was formed by winding a 0.1 mm urethane-coated conductive wire by 80 turns. A 18 μm-thick magnetic ribbon made of a Co-based amorphous alloy was penetrated into the hollow portion of the coil portion, and both ends were bent to the side surfaces of the insulating bobbin so as to form a closed magnetic circuit structure. Further, a polyester tape is used as the insulating tape, and the insulating tape is wound around the winding portion for 1.5 turns so that the longitudinal direction is at 90 degrees to the longitudinal direction of the magnetic ribbon, and the overlapping portion of the magnetic ribbon is fixed. An inductance element was manufactured (Example 1). Example 3 was an inductance element in which the longitudinal direction of the insulating tape was at 70 degrees to the longitudinal direction of the magnetic ribbon. As Example 4, a U-shaped clip was inserted into the winding portion instead of the insulating tape, and a magnetic ribbon was fixed.

The inductance elements of the second and fifth embodiments are different from those of the first embodiment in that the insulating bobbin shown in FIG.
Is formed using an insulating bobbin provided with a flange that makes one round of the outer circumference (referred to as a bobbin shape "B") as shown in Fig. 5, and the angle between the longitudinal direction of the insulating tape and the longitudinal direction of the magnetic ribbon. Are 90 degrees and 120 degrees, respectively.

As Comparative Examples 1 and 2, bobbins having the same shape as in Example 1 were used, and the angles formed by the longitudinal direction of the insulating tape and the longitudinal direction of the magnetic ribbon were 0 ° and 45 °, respectively. An inductance element was manufactured.

Next, these Examples 1 to 5 and Comparative Examples 1 and 2
The inductance element, the shortest distance (S) between the winding and the magnetic ribbon, and the shock resistance were measured for the inductance element of (1). The results are shown in Table 1 together with the workability. The inductance was measured at 50 kHz and 0.01 V. In Table 1, the workability was 95%.
%, 90% or more and less than 95%, "○", 80% or more and less than 90%, "△", and 8
Those with less than 0% were indicated by "x". The impact was evaluated by dropping naturally onto a wooden floor from a height of 1 m 10 times. If the ratio of those with a defective shape was less than 1%, it was evaluated as "「 ". × ”.

[Table 1]

As is clear from the results shown in Table 1,
It has been found that any of those having an angle θ between the longitudinal direction of the insulating tape and the longitudinal direction of the magnetic ribbon within the range of the present invention has little change in shape with respect to impact and has excellent workability. On the other hand, it was recognized that the comparative example was poor in workability and weak in impact. In particular, if the longitudinal direction of the insulating tape is the same as the longitudinal direction of the magnetic ribbon,
It has been found that the shortest distance (S) between the winding and the magnetic ribbon increases, and as a result, the inductance decreases.

Examples 6 to 8 and Comparative Example 3 In the inductance element of Example 1, an inductance element in which the width of the insulating tape (W _t ) and the length of the winding portion (L _b ) of the insulating bobbin were changed was manufactured. In Examples 6 to 8,
(W _t / L _b ) was set to be in the range of 0.4 to 1.0, and in Comparative Example 3, it was set to be less than 0.4.

Next, the impact characteristics of the inductance elements of Examples 6 to 8 and Comparative Example 3 were measured in the same manner as in Example 1. The results are shown in Table 2 together with the workability. The display of the results of the workability and impact in Table 2 is the same as that in Table 1.

[Table 2]

As is clear from the results shown in Table 2,
It was found that those having (W _t / L _b ) in the range of 0.4 to 1.0 had excellent workability and were strong against impact. On the other hand, when (W _t / L _b ) was less than 0.4, it was recognized that the workability was not significantly changed, but the material was weak to impact.

Examples 9 to 11 and Comparative Example 4 In the inductance element of Example 1, a magnetic ribbon not subjected to heat treatment was used, and the minimum radius of curvature R of the curved portion of the magnetic ribbon was 0.8 (mm). ) Was manufactured (Example 9). Further, as Examples 10 and 11, inductance elements were manufactured in which the shape of the insulating bobbin was changed and the minimum curvature radii R of the curved portions of the magnetic ribbon were 1.5 and 0.3 (mm), respectively.

As Comparative Example 4, using the same insulating bobbin as in Example 1 and using a magnetic ribbon subjected to heat treatment, the minimum radius of curvature R of the curved portion of the magnetic ribbon was 0.8 ( m
An inductance element that satisfies m) was manufactured.

For each of the above inductance elements, the occurrence of cracks and the like (workability) in the magnetic ribbon was examined. Table 3 shows the results. In the workability shown in Table 3, “」 ”indicates that the ratio of no cracks or the like in the magnetic ribbon was 90% or more, and“ x ”indicates that no cracks or the like occurred in the magnetic ribbon. Indicates that the ratio of the refuse is less than 30%.

[Table 3]

As is clear from the results shown in Table 3,
Examples 9 to 11 using magnetic ribbons not subjected to heat treatment
In each case, it was confirmed that the occurrence of cracks and the like in the magnetic ribbon was suppressed to a low level.

Examples 12 to 14 and Comparative Examples 5 to 7 The inductance elements of Example 1 were manufactured by changing the number of turns of the windings to 30, 100, and 150. And In Comparative Examples 5, 6, and 7, the longitudinal direction of the insulating tape and the longitudinal direction of the magnetic ribbon in the inductance element of Example 1 were set to the same direction, and the number of turns was 30, 100, 1
An inductance element having a value of 50 was produced.

The inductances of the inductance elements of Examples 12 to 14 and Comparative Examples 5 to 7 were measured. Table 4 shows the results. The inductance is 50k
The measurement was performed at 0.01 Hz and Hz.

[Table 4]

As is evident from Table 4, it was confirmed that the larger the number of turns, the better the inductance characteristics.
Further, it was confirmed that when the number of turns was the same, the inductance characteristics were improved when the longitudinal direction of the insulating tape was perpendicular to the longitudinal direction of the magnetic ribbon as compared with the case where the longitudinal direction was parallel.

Example 15, Comparative Example 8 An inductance element having the same number as that of Example 1 except that the number of laminated magnetic ribbons was 3 was manufactured.
And Further, as Comparative Example 8, an inductance element was prepared in which the longitudinal direction of the insulating tape and the longitudinal direction of the magnetic ribbon in Example 1 were set to the same direction, and the number of laminated magnetic ribbons was three.

The inductances of the inductance elements of Example 15 and Comparative Example 8 were measured. Table 5 shows the results. The inductance is 50 kHz, 0.1.
The measurement was performed at 01V.

[Table 5]

As is apparent from Table 5, it was recognized that the inductance characteristics were improved by increasing the number of laminated magnetic ribbons. In addition, it was recognized that the inductance characteristics were improved when the longitudinal direction of the insulating tape was perpendicular to the longitudinal direction of the magnetic ribbon, as compared with the case where the longitudinal direction of the magnetic tape was parallel.

[0074]

According to the present invention, there is provided a coil section in which a winding is formed on an insulating bobbin, a core section having a closed magnetic circuit structure at least partially disposed inside the insulating bobbin, and the magnetic ribbon fixed. In the inductance element provided with the insulating tape, the angle between the longitudinal direction of the insulating tape and the longitudinal direction of the magnetic ribbon is 60 degrees to 120 degrees, so that the joining portion of the magnetic ribbon is disengaged by impact. This can be suppressed, and the inductance can be improved by shortening the distance between the magnetic ribbon and the winding.

[Brief description of the drawings]

FIG. 1 is an external view showing an inductance element of the present invention.

FIG. 2 is a sectional view showing an inductance element of the present invention.

FIG. 3 is a plan view showing an inductance element of the present invention.

FIG. 4 is an enlarged sectional view showing a part of the inductance element of the present invention.

FIG. 5 is an external view showing an example of an insulating bobbin used for the inductance element of the present invention.

FIG. 6 is a circuit diagram showing a snubber circuit of the present invention.

FIG. 7 is a sectional view showing a conventional inductance element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Inductance element 2 ... Insulating bobbin 3 ... Flange 5 ... Winding part 6 ... Winding 7 ... Magnetic ribbon 8 ... Insulating tape 9 ... Longitudinal direction of magnetic ribbon 10 ... Insulating tape Longitudinal direction of the snubber circuit 19

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02M 3/28 H02M 3/338 A 3/338 H01F 27/24 E

Claims (9)

[Claims] 1. The number of turns (N) per 10 mm length is 20
A coil of at least 500 or less is formed on an insulator bobbin having flanges at both ends, and a magnetic ribbon of a single layer or a plurality of layers having a thickness of 4 μm or more and 50 μm or less and a width of 1 mm or more and 40 mm or less. An inductance element partially including a core portion having a closed magnetic circuit structure disposed inside the insulator bobbin, and an insulating tape for fixing the magnetic ribbon, wherein the number of turns (N) of the coil and the magnetic property The ratio (N / n) to the number of layers (n) of the ribbon is 20 or more and 500 or less, and the angle between the longitudinal direction of the insulating tape and the longitudinal direction of the magnetic ribbon is 60 to 120 degrees. An inductance element, comprising: 2. The inductance element according to claim 1, wherein the angle between the longitudinal direction of the insulating tape and the longitudinal direction of the magnetic ribbon is 90 degrees. 3. The inductance element according to claim 1, wherein the insulating tape is formed so as to make at least one round around the insulating bobbin. 4. The insulating tape according to claim 1, wherein a width (W _t ) of the insulating tape is not less than 0.4 and not more than 1.0 of a length (L _b ) of a winding portion of the insulating bobbin. The inductance element according to any one of the above. 5. The inductance element according to claim 1, wherein a distance between a winding and a magnetic ribbon at a central portion of a winding portion of the insulating bobbin is within 1 mm. . 6. The inductance element according to claim 5, wherein the winding and the magnetic ribbon are in contact with at least one portion. 7. The inductance element according to claim 1, wherein the height of the flange is higher than the height of the coil portion. 8. The inductance element according to claim 1, wherein the magnetic ribbon is a magnetic ribbon that has not been subjected to a heat treatment. 9. A snubber circuit comprising the inductance element according to claim 1 connected to a drive circuit of a switching element.