JP2002093631A - Magnetic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic device which is reduced in size, without reducing the saturation magnetic flux density. SOLUTION: The magnetic device has a bar-shaped magnetic core 10, made of a magnetic material having a resistivity of about 103 Ωm or larger, a flat rectangular wire 1 wound edgewise around the bar-shaped magnetic core 10, and a metal magnetic core 20 held in the bar-shaped magnetic core 10. The magnetic device is reduced in size by winding the flat rectangular wire 1 around the bar-shaped magnetic core 10, having a resistivity and by holding the metallic magnetic core 20 in the bar-shaped magnetic core 10, without a bobbin made of an insulating material such as in a conventional magnetic device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic device, and more particularly to an electromagnetic device for generating a high-voltage pulse used for a starting device of a high-pressure discharge lamp.

[0002]

2. Description of the Related Art Hitherto, there has been provided a device for generating a high-voltage pulse called an igniter for starting a high-pressure discharge lamp. This igniter includes a pulse transformer, which is an electromagnetic device for converting a low voltage to a high voltage. I have it.

A conventional pulse transformer is shown in FIGS.
As shown in the figure, a bobbin 71 made of an insulating material formed in a substantially cylindrical shape as a whole, primary and secondary windings 81 and 82 wound around the bobbin 71, and a part made of, for example, Mn-Zn ferrite. And a pair of magnetic cores 72, 72 inserted inside the bobbin 71.

As shown in FIG. 16, the bobbin 71 has a substantially cylindrical main body 71a, and flange portions 71b, 71c located at both longitudinal ends of the main body 71a and projecting from the main body 71a in a direction substantially perpendicular to the longitudinal direction. And a partition 71d projecting from the main body 71a in a direction substantially perpendicular to the longitudinal direction to separate the primary winding 81 and the secondary winding 82, and are formed in a so-called divided bobbin structure.

[0005] The primary winding 81 is formed by winding an electric wire having a substantially circular cross section so as to fit between the partition wall 71d of the bobbin 71 and one flange portion 71b.
Is formed by winding a rectangular wire having a substantially rectangular cross section in one layer edgewise so as to fit between the partition 71d of the bobbin 71 and the other flange 71c.

A pair of magnetic cores 72, 72 are respectively
It is formed in a substantially U-shape with a quadrangular columnar portion 72b and a columnar portion 72c that project substantially perpendicularly from 2a and are substantially opposed to each other. In the pair of magnetic cores 72, 72, the pillars 72c, 72c are respectively inserted into the bobbin 71 through openings at both longitudinal ends thereof so as to be substantially opposed to each other, and the respective pillars 72b, 72b are positioned outside the bobbin 71. They are arranged so as to be substantially opposed to each other.

In such a conventional pulse transformer, the secondary winding 81 is formed of a rectangular wire with an edgewise winding, so that the insulation on the creeping surface and the winding occupancy are improved.

[0008]

However, in recent years, high pressure discharge lamps have been used for headlights of automobiles and the like, and have rapidly become widespread.
A thin pulse transformer is required. In addition, in the required specifications of a headlight of an automobile, a high-pressure discharge lamp requires a difficult restart, which requires an igniter to generate a pulse voltage of several tens of kV when starting the high-pressure discharge lamp. Have been.

However, when the conventional pulse transformer is miniaturized, there is a problem that the effective magnetic core area is reduced, the saturation magnetic flux density is reduced, and when the transformer is provided in an igniter, the pulse voltage generated from the igniter is reduced. Was.

In the above-mentioned conventional example, the pulse transformer is described as an electromagnetic device. However, even if the electromagnetic device is a single-winding inductor in which only the rectangular wire 1 is wound around a bobbin, as described above, if the size is reduced, the saturation magnetic flux density decreases. There was a problem of becoming.

An object of the present invention is to solve the above-mentioned problems, and to provide an electromagnetic device which is reduced in size without lowering the saturation magnetic flux density.

[0012]

In order to achieve the above object, the present invention is directed to a rod-shaped core made of a magnetic material having a resistivity of about 10 ³ Ωm or more, and edgewise wound around the rod-shaped core. It is characterized by having a flat wire and a metal core held inside the bar-shaped core, and by winding the flat wire around a high-resistivity bar-shaped core, made of an insulating material as in the conventional example. By eliminating the need for a bobbin and holding the metal core inside the rod-shaped core, it is possible to reduce the size without reducing the saturation magnetic flux density.

According to a second aspect of the present invention, in the first aspect of the present invention, a hole is formed in the rod-shaped magnetic core so as to penetrate along the longitudinal direction, and a metal-based magnetic core is inserted and held in the hole. This has the same effect as the first aspect of the present invention.

According to a third aspect of the present invention, in the first aspect of the present invention, a bottomed hole is formed in the rod-shaped core, and a metal core is inserted and held in the hole. One end of the metal core is covered with the rod-shaped core without being exposed to the outside, so that even when a high voltage is applied to a rectangular wire, the occurrence of dielectric breakdown through the metal core is suppressed, and the pressure resistance is improved. be able to.

According to a fourth aspect of the present invention, in the second or third aspect of the present invention, the cross section of the rod-shaped magnetic core substantially perpendicular to the longitudinal direction is formed in a substantially elliptical shape, and the opening surface of the hole is formed in a substantially rectangular shape. The metal core is characterized by stacking a plurality of steel plates.By forming a metal core by stacking a plurality of steel plates, high-frequency characteristics can be improved. The number of steel plates can be reduced by stacking a plurality of steel plates along a direction substantially perpendicular to the longitudinal direction of the opening surface.

According to a fifth aspect of the present invention, in any one of the second to fourth aspects, a plurality of holes are formed.
At the time of forming the rod-shaped core, deformation of each hole of the rod-shaped core can be suppressed by a portion separating the plurality of holes of the rod-shaped core, and the metal core can be smoothly inserted into each hole.

According to a sixth aspect of the present invention, in the fifth aspect of the invention, each metal core inserted into each hole is integrally formed outside the opening surface of each hole, and the number of parts is reduced. It is possible to reduce the number and improve the assemblability.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects of the present invention, the metal core is made of silicon steel. To play.

According to an eighth aspect of the present invention, in any one of the first to sixth aspects, the metal core is formed of a dust core. Play.

According to a ninth aspect of the present invention, in any one of the first to sixth aspects, the metal core is made of an amorphous material. To play.

According to a tenth aspect of the present invention, in any one of the first to ninth aspects, the rod-shaped magnetic core is made of NiZn ferrite, and has the same effect as any of the first to ninth aspects. Play.

According to an eleventh aspect of the present invention, in any one of the first to tenth aspects, a winding is wound on a flat wire wound around a rod-shaped magnetic core, and the wound flat wire and the winding are connected to each other. Thus, a reduction in the secondary output voltage due to a decrease in the saturation magnetic flux density can be suppressed and the size can be reduced.

According to a twelfth aspect of the present invention, in any one of the first to eleventh aspects, at least the rod-shaped core wound with a flat wire is sealed with a resin material to improve reliability. Can be.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) In this embodiment, as shown in FIGS. 1A and 1B, a rod-shaped core 10 made of a magnetic material and an edgewise winding around the rod-shaped core 10. This is a single-wound inductor including the rectangular wire 2 and the metal core 20 held inside the rod-shaped core 10.

The rod-shaped magnetic core 10 is formed in a substantially cylindrical shape by NiZn ferrite material having for example, a high resistivity of about 10 ³ [Omega] m or more resistivity, the diameter of the longitudinal direction substantially perpendicular to the circular cross-section, for example, as about 8mm I have. Further, a hole 11 penetrating along the longitudinal direction is formed in the rod-shaped magnetic core 10, and a cross section substantially perpendicular to the penetrating direction of the hole 11 has a substantially rectangular shape. The metal magnetic core 20 is formed in a substantially quadrangular prism shape, and is inserted and held in the hole 11 described above. Here, the metal core 20 is formed of, for example, silicon steel, dust core, amorphous material, or the like.

The flat wire 2 has a cross-sectional width of, for example, about 1 m.
m and a thickness dimension of about 0.1 mm, and in this embodiment, unlike the conventional example, the flat wire 2 is directly connected to the rod-shaped core 10 without an insulator such as a bobbin.
Is wound further over the entire length in the longitudinal direction.

As described above, in the present embodiment, the flat wire 2 is directly wound around the rod core 10 having a high specific resistance, thereby eliminating the need for a bobbin. Further, the rod core 10 is formed of NiZn ferrite having a small magnetic permeability. Even if it is performed, by holding the metal magnetic core 20 inside the rod-shaped magnetic core 10, the size can be reduced without increasing the inductance and reducing the saturation magnetic flux density.

In the present embodiment, the rectangular wire 2 is wound directly around the bar-shaped magnetic core 10. However, the rectangular wire 2 is wound around the jig in advance by using a special jig, and the edge-wise is wound. The wound flat wire 2 may be inserted into the rod-shaped magnetic core 10. At this time, a thin sheet made of an insulating material is previously arranged on the surface of the jig, and a flat wire 2
After winding the sheet, the sheet is slid on the jig surface, and the wound flat wire 2 is inserted into the rod-shaped core 10 together with the sheet, whereby the insertion into the rod-shaped core 10 can be facilitated. (Embodiment 2) Here, since the metal magnetic core 20 of Embodiment 1 is formed in a substantially quadrangular prism shape and has a thickness in a cross-sectional dimension substantially perpendicular to the longitudinal direction, a high-frequency voltage is applied to both ends of the flat wire 2. Occasionally, the electrical loss increased.

Therefore, the metal core 20 of the present embodiment is formed in a block shape as shown in FIG. 2B by stacking a plurality of substantially rectangular flat steel plates 21 shown in FIG. Thereby, high frequency characteristics can be improved.
When the steel plate 21 is formed of silicon steel or a metal having directionality (for example, directional silicon steel), the high-frequency characteristics can be further improved. (Embodiment 3) Since the basic configuration in this embodiment is common to Embodiment 1 or 2, the same parts are denoted by the same reference numerals, and description thereof is omitted. Will be described.

In this embodiment, as shown in FIG. 3, unlike the first embodiment, a hole 12 having a bottom is provided without providing a hole 11 penetrating through the rod-shaped magnetic core 10, and a metal having a bottom is provided so as to fit in the hole 12. The system magnetic core 20 is inserted and held.

As a result, one end in the longitudinal direction of the metal core 20 inserted into the hole 12 is not exposed to the outside, and the rod-shaped core 1
Since it is covered with 0, even when a high voltage is applied to both ends x and y of the rectangular wire 2 in FIG. 3, the occurrence of dielectric breakdown via the metal-based magnetic core 20 is suppressed, and the pressure resistance can be improved. (Embodiment 4) Since the basic configuration in this embodiment is common to Embodiments 1 to 3, the same reference numerals are given to the common parts, and the description thereof will be omitted. Will be described.

In the present embodiment, the rod-shaped core 10 is made of, for example, ferrite, and the metal core 20 is not inserted and held in the holes 11 and 12 provided in the rod-shaped core 10 as in the first to third embodiments. When the bar-shaped core 10 is formed, the metal-based core 20 is disposed in the ferrite before sintering the ferrite, and then the ferrite is sintered to form the bar-shaped core 10. The magnetic core 20 is held.

As a result, as shown in FIGS. 4A and 4B, the metal core 20 is sealed without being exposed to the outside of the rod core 10, and a component having a different electric potential is provided around the rod core 10. Even if they are arranged, the occurrence of metal destruction via the metal-based magnetic core 20 is not promoted by the components, and the pressure resistance can be further improved. (Embodiment 5) Since the basic configuration in this embodiment is common to Embodiment 2 or 3, the same reference numerals are given to the common parts and the description thereof will be omitted, and only the parts which are the features of this embodiment will be described in detail. Will be described.

As shown in FIG. 5, the rod-shaped core 10 of this embodiment has a substantially elliptical cross section substantially perpendicular to the longitudinal direction, and the opening surface of the hole 12 is elongated along the longitudinal direction of the cross section. It is formed so as to be substantially rectangular. And
As shown in FIG. 6, the metal core 20 is formed by stacking a plurality of steel plates 21 made of, for example, silicon steel, and the stacking direction is substantially perpendicular to the longitudinal direction of the opening surface of the hole 12, similarly to the second embodiment. Into the hole 12. As a result, the number of the steel plates 21 can be suppressed and the high frequency characteristics can be improved.

Further, in the present embodiment, as shown in FIG. 7, the rectangular wire 2 is used for edgewise winding the flat wire 2 around the other end opposite to the one end where the opening surface of the hole 12 in the longitudinal direction of the rod core 10 is located. A winding recess 13 is provided.

Here, the procedure for winding the flat wire 2 around the rod-shaped magnetic core 10 will be briefly described. When the rectangular wire 2 is wound around the rod-shaped magnetic core 10, the rectangular wire 2 is wound using, for example, the winding jigs A and B shown in FIG. Turn.

The winding jig A has a hole 1 of a rod-shaped magnetic core 20 at one end.
The coil jig B has a substantially rectangular flat-shaped insertion section A1 having a substantially rectangular flat plate-shaped insertion section A1 to be inserted into the second insertion section 2. The fitting portion A1 of the winding jig A is fitted into the hole 12 of the rod-shaped magnetic core 10, and the winding recess 13 of the rod-shaped magnetic core 10 is further formed.
Insert the tip of the winding jig B into the jig. At this time, winding jig B
Are in contact with the periphery of the winding recess 13 of the rod-shaped core 10, and the winding jigs A and B are arranged along the longitudinal direction of the rod-shaped core 20.

Then, the winding jig A is rotated about a substantially central axis along the insertion direction of the insertion portion A1, and the rod-shaped magnetic core 10 is rotated with the rotation, and the flat wire 2 is wound around the rod-shaped magnetic core 10. Go.

As described above, in the present embodiment, the rod-shaped core 10
By using the winding jigs A and B with the winding recess 13 provided in the core, the rotation of the rod-shaped magnetic core 10 can be stabilized, and the flat wire 2 can be wound around the rod-shaped magnetic core 10 with high accuracy.

In this embodiment, as shown in FIG. 8, an electric wire is wound on a rectangular wire 2 wound around a rod-shaped magnetic core 12 to form a winding 1, and the wound rectangular wire 2 and the winding are formed. A transformer configuration may be used with the line 1. For example, the winding 1 is used as a primary winding, the wound rectangular wire 2 is used as a secondary winding, and the winding 1 is arranged closer to the smaller potential of the rectangular wire 2. With such a configuration, for example, it can be used as a pulse transformer provided in an igniter, and the reduction of the pulse voltage generated from the igniter can be suppressed without lowering the secondary output voltage of the pulse transformer. In comparison, the pulse transformer can be downsized.

Further, the above-mentioned pulse transformer may be sealed with a resin material such as epoxy, silicon, polyester or the like, in which case the reliability can be improved. (Embodiment 6) By the way, as shown in FIG. 9 (a), a cross section substantially perpendicular to the longitudinal direction of the rod-shaped magnetic core 10 of Embodiment 5 is shown in FIG.
By sintering the rod-shaped magnetic core 10 made of, for example, ferrite by making the opening surface of the hole 12 elongated along the longitudinal direction of the cross section, the hole 12 has a substantially oval shape.
As shown in (b), the wide side wall 14 of the rod-shaped magnetic core 10 hangs down, the opening surface size of the hole 12 becomes small, and the metal core 20 cannot be inserted into the hole 12 in some cases.

Therefore, the rod-shaped magnetic core 10 of the present embodiment is similar to that of FIG.
As shown in FIG. 0, a support wall 15 is provided inside the hole 12. The support wall 15 is formed integrally with the inside of wide side walls 14, 14 of the rod-shaped magnetic core 10, which are located substantially at the center of the hole 12 and are substantially opposed to each other. The support wall 15 forms two holes 12a in the rod-shaped core 10, and the metal core 20 is inserted into each of the holes 12a.

In the present embodiment, since the support wall 15 as described above is provided and two holes 12a are formed, even when the rod-shaped magnetic core 10 is sintered, the support wall 15 respectively forms the side walls 14, 14 of the rod-shaped magnetic core 10. Supported from the inside of the hole 12,
The sagging of the side walls 14, 14 can be prevented. As a result, the deformation of each hole 12a can be suppressed, and the metal magnetic core 20 can be smoothly inserted into each hole 12a.

Although two holes 12a are provided in the present embodiment, three or more holes 12a may be provided so that the metal core 20 is inserted into and held in each hole. (Embodiment 7) Since the basic configuration of this embodiment is common to that of Embodiment 6, the same parts are denoted by the same reference numerals and the description thereof will be omitted, and only the characteristic parts of this embodiment will be described in detail. I do.

In this embodiment, the rod-shaped magnetic core 1 of the sixth embodiment
As shown in FIG. 11, the metal cores 20 inserted into the holes 12a, 12a are generally formed in a substantially U-shape so as to be integrated outside the opening surface of each hole 12a. Is formed.

Thus, the number of parts can be reduced, and each of the metal cores 20 is connected to the hole 1 of the rod-shaped core 10 from the other end opposite to the one end integrated in the longitudinal direction.
2a, 12a can be inserted and held at once,
The assemblability can be improved.

In the present embodiment, as shown in FIG. 12, similar to the second embodiment, substantially flat U-shaped steel plates 21a made of, for example, silicon steel are stacked, and the two metal bases integrated as described above are integrated. The magnetic cores 20, 20 may be configured, and in this case, high-frequency characteristics can be improved.

In this embodiment, two holes 12a are provided and two metal cores 20 inserted into each hole 12a are integrated. However, when three or more holes are provided, Three or more metal-based magnetic cores 20 inserted into each hole may be integrated.

[0049]

According to the first aspect of the present invention, a rod-shaped core made of a magnetic material having a resistivity of about 10 ³ Ωm or more, a flat wire edgewise wound around the rod-shaped core, and a rod-shaped core held inside the rod-shaped core. With a metal core, which eliminates the need for a bobbin made of an insulating material as in the conventional example.Moreover, by holding the metal core inside the rod-shaped core, it is possible to reduce the size without reducing the saturation magnetic flux density. There is an effect that can be achieved.

According to the second aspect of the present invention, a hole is formed in the rod-shaped magnetic core so as to penetrate the magnetic core in the longitudinal direction, and the metal core is inserted and held in the hole. To play.

According to the third aspect of the present invention, since a bottomed hole is formed in the rod-shaped core and the metal core is inserted and held in the hole, one end of the metal core inserted into the hole is exposed to the outside. Instead of being covered by the rod-shaped magnetic core, even when a high voltage is applied to the rectangular wire, the occurrence of dielectric breakdown via the metal-based magnetic core is suppressed, and there is an effect that the pressure resistance can be improved.

According to a fourth aspect of the present invention, the cross section substantially perpendicular to the longitudinal direction of the rod-shaped core is formed in a substantially elliptical shape, and the opening surface of the hole is formed in a substantially rectangular shape. The high-frequency characteristics can be improved, and the opening surface of the hole is formed in a substantially rectangular shape, so that a plurality of steel plates are stacked along a direction substantially perpendicular to the longitudinal direction of the opening surface. There is an effect that the number of sheets can be reduced.

According to the fifth aspect of the present invention, since a plurality of holes are formed, deformation of each hole of the rod core can be suppressed by a portion separating the plurality of holes of the rod core when the rod core is formed. There is an effect that the magnetic core can be smoothly inserted into each hole.

According to a sixth aspect of the present invention, since each metal magnetic core inserted into each hole is integrally formed outside the opening surface of each hole, the number of parts can be reduced and assemblability can be reduced. There is an effect that it can be improved.

According to the seventh aspect of the invention, since the metal magnetic core is made of silicon steel, the same effect as any of the first to sixth aspects of the invention is obtained.

According to the eighth aspect of the present invention, since the metal-based magnetic core is made of a dust core, the same effect as any of the first to sixth aspects of the invention is obtained.

According to the ninth aspect of the present invention, since the metal magnetic core is made of an amorphous material, the same effect as any of the first to sixth aspects of the invention can be obtained.

According to a tenth aspect of the present invention, the bar-shaped magnetic core is NiZ
Since it is made of n-ferrite, the same effect as any of the first to ninth aspects of the invention can be obtained.

According to the eleventh aspect of the present invention, the winding is wound on a rectangular wire wound around a rod-shaped magnetic core, and the wound rectangular wire and the winding form a transformer. Thus, there is an effect that the reduction in the secondary side output voltage due to the above can be suppressed and the size can be reduced.

According to the twelfth aspect of the present invention, at least the rod-shaped magnetic core on which the rectangular wire is wound is sealed with a resin material, so that the reliability can be improved.

[Brief description of the drawings]

FIG. 1A is a perspective view, and FIG. 1B is a sectional view, showing a first embodiment.

FIGS. 2A and 2B are perspective views showing a metal-based magnetic steel sheet according to a second embodiment, and FIG.

FIG. 3 is a sectional view showing a third embodiment.

4A is a perspective view, and FIG. 4B is a cross-sectional view, showing a fourth embodiment.

FIG. 5 is a perspective view showing a bar-shaped magnetic core with a rectangular wire wound thereon and a winding jig according to a fifth embodiment.

FIG. 6 is a perspective view showing the metal core according to the first embodiment;

FIG. 7 is a sectional view of the above.

FIG. 8 is a perspective view when the transformer configuration is used.

FIGS. 9 (a) and 9 (b) are perspective views for explaining a sixth embodiment showing the rod-shaped magnetic core of the fifth embodiment.

FIG. 10 is a perspective view showing a rod-shaped magnetic core of a sixth embodiment.

FIG. 11 is a perspective view showing a metal core according to a seventh embodiment.

FIG. 12 is a perspective view showing another metal-based magnetic core of the above.

FIG. 13 is an exploded perspective view showing a conventional example.

FIG. 14 is a perspective view of the same.

FIG. 15 is a sectional view of the above.

FIG. 16 is a perspective view of the bobbin.

[Explanation of symbols]

 2 Flat wire 10 Bar-shaped core 11 Hole 20 Metal core

Claims (12)

[Claims] 1. A bar-shaped core made of a magnetic material having a resistivity of about 10 ³ Ωm or more, a rectangular wire edgewise wound around the bar-shaped core, and a metal core held inside the bar-shaped core. An electromagnetic device, characterized in that: 2. The electromagnetic device according to claim 1, wherein a hole penetrating along the longitudinal direction is formed in the rod-shaped core, and a metal core is inserted and held in the hole. 3. The electromagnetic device according to claim 1, wherein a bottomed hole is formed in the rod-shaped magnetic core, and a metal core is inserted and held in the hole. 4. A cross section substantially perpendicular to the longitudinal direction of the rod-shaped magnetic core,
4. The electromagnetic device according to claim 2, wherein the electromagnetic device is formed in a substantially elliptical shape, the opening surface of the hole is formed in a substantially rectangular shape, and the metal core is formed by stacking a plurality of steel plates. 5. The electromagnetic device according to claim 2, wherein a plurality of holes are formed. 6. The electromagnetic device according to claim 5, wherein each metal magnetic core inserted into each hole is integrally formed outside the opening surface of each hole. 7. The electromagnetic device according to claim 1, wherein the metal core is made of silicon steel. 8. The electromagnetic device according to claim 1, wherein the metal core is made of a dust core. 9. The electromagnetic device according to claim 1, wherein the metal core is made of an amorphous material. 10. The electromagnetic device according to claim 1, wherein the rod-shaped magnetic core is made of NiZn ferrite. 11. The transformer according to claim 1, wherein a winding is wound on a rectangular wire wound around a rod-shaped magnetic core, and the wound rectangular wire and the winding form a transformer. An electromagnetic device according to any of the claims. 12. A bar-shaped magnetic core on which at least a flat wire is wound is sealed with a resin material.
12. The electromagnetic device according to any one of claims 11 to 11.