JPH0513022U - Magnetic core with gear - Google Patents

Abstract

(57) [Summary] (Modified) [Objective] To provide a magnetic core with a gap for a coil device, which is downsized and thinned without sacrificing electromagnetic characteristics such as an inductor L and an impedance Z. [Structure] In a coil device using a UI type magnetic core, I
When the thickness of the magnetic core 12 is made smaller than that of the U-shaped core 11 and the coil is wound around the winding portion, the I-shaped core 12
If the I-shaped magnetic core 12 is eccentrically arranged so as not to project from the lower surface of the U-shaped magnetic core 11, the electromagnetic characteristics of the inductor L, the impedance Z, etc. are not sacrificed, and the coil Since it is possible to eliminate the protrusion amount on one side or reduce the protrusion amount as compared with the conventional one, it is possible to provide a magnetic core 10 with a gap for a coil device, which is miniaturized in the height direction, and which is a circuit board or the like. The whole device can be made thinner when mounted on the.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a magnetic core with a gap, which is used as a magnetic core of various coil devices such as a transformer and a choke coil and constitutes a magnetic circuit by combining a U-shaped magnetic core and an I-shaped magnetic core.

[0002]

[Prior Art]

 In recent years, with the miniaturization and thinning of electric and communication devices, the demand for high-density mounting has been increasing. In this case, mounting is often facilitated by using a component having a reduced height and a reduced thickness due to mounting on a substrate or the like. Conventionally, as a magnetic core with a gap forming a transformer, a choke coil, or the like, a UI magnetic core in which a magnetic core formed in a U shape and a magnetic core formed in an I shape are combined with a magnetic material such as ferrite is conventionally used. It is used.

As a coil device using this UI magnetic core, the UI coil device shown in FIG. 5 has been conventionally used. The UI type coil device 1 shown in the figure comprises a U-shaped magnetic core 2, an I-shaped magnetic core 3, an I-shaped coil portion 6 composed of a resin bobbin 4 and a coil 5. The I-shaped magnetic core is arranged between the two leg portions 2a and 2b of the U-shaped magnetic core 2 so that a gap 7 is formed on one side or both end surfaces of the U-shaped magnetic core 2 to form a magnetic path. The coil 5 is wound via. FIG. 6 is a sectional view taken along the line AA in FIG. When the coil 5 is wound to form the coil device 1, since the U-shaped magnetic core and the I-shaped magnetic core are generally uniform in thickness, the bobbin 4 is provided on the outer periphery of the I-shaped magnetic core 3. Then, when the coil 5 is wound, the coil 5 or the bobbin 4 has a structure protruding from the upper and lower surfaces of the I-shaped magnetic core 3, and the overall height H1 of the coil device is equal to the thickness t3 of the I-shaped magnetic core of the coil 3. It is a value obtained by adding the thickness t5 and the thickness t4 of the bobbin 4 around which the coil 3 is wound. Therefore, the UI core having the above structure has a structure in which the coil 5 or the bobbin 4 projects from both sides of the coil device 1 to the same extent, and is not suitable for downsizing and thinning in the height direction.

[0004]

[Problems to be solved by the device]

 The present invention has been made in view of the above circumstances, and a magnetic core with a gap for making the coil device smaller and thinner without deteriorating the electromagnetic characteristics of the inductor L, the impedance Z, and the like. It is intended to provide.

[0005]

[Means for Solving the Problems]

 In a magnetic core with a gap in which an I-shaped magnetic core is arranged so that a magnetic path is formed through a gap between both legs of the U-shaped magnetic core, the thickness of the I-shaped magnetic core is smaller than the thickness of the U-shaped magnetic core. It is also characterized in that the central position of the I-shaped magnetic core in the thickness direction is deviated from the central position of the U-shaped magnetic core in the thickness direction.

[0006]

[Action]

 According to the UI type magnetic core with a gap configured as described above, the form of the coil device can be made smaller and thinner, and when the coil is wound around the winding portion, the coil or the bobbin is formed. If the thickness and displacement of the I-shaped magnetic core are selected so that does not excessively protrude from one side surface of the U-shaped magnetic core in the thickness direction, the side where the coil does not protrude or the side where the amount of protrusion is small is the circuit board. If the mounting side is such as, the height direction of the mounting part can be made smaller.

[0007]

【Example】

 Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an external perspective view of a magnetic core 10 with a gap for a coil device according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along line BB in FIG.

The gap-provided core 10 has a U-shaped magnetic core 11 having a quadrangular cross section, and an I-shaped magnetic core 12 having a quadrangular cross section between the inner surfaces of the legs 11a and 11b. It is configured by combining the gap 13 with a gap material (not shown) made of polyester film, glass, rubber or the like. The magnetic core 10 with a gap is formed by firing ferrite powder, for example, and forms a substantially mouth-shaped magnetic path. The thickness t12 of the I-shaped magnetic core 12 is thinned to 0.2 to 0.8 times (0.5 times in this example) the thickness t11 of the U-shaped magnetic core 11, as shown in FIG. There is. Further, the I-shaped magnetic core 12 is arranged at a position displaced downward in the thickness direction of the U-shaped magnetic core 11 and does not project from the lower side surface 11b of the U-shaped magnetic core 11 in the thickness direction. By doing so, when the coil 14 is wound around the I-shaped magnetic core 12, the coil 14 does not protrude from the upper side surface 11 of the U-shaped magnetic core 11. Even if the ratio of the thickness t12 of the I-shaped magnetic core 12 to the thickness t11 of the U-shaped magnetic core 11 increases to about 0.8, the central position of the I-shaped magnetic core 12 in the thickness direction is the U-shaped magnetic core 11. In the thickness direction of the U-shaped magnetic core 11, when the coil 14 projects from the upper surface 11a of the U-shaped magnetic core 11, the projecting amount of the coil 14 is smaller than that of the coil 14 of the lower surface 11b. As far as the upper surface 11a is concerned, the protrusion amount of the coil 14 is greatly reduced as compared with the conventional magnetic core with a gap as shown in FIG.

According to the magnetic core with a gap as in the first embodiment, when the coil 14 is wound around the I-shaped magnetic core 12, the coil 14 is wound from the upper surface 11 a of the U-shaped magnetic core 11 to the coil 14. The coil device itself can be thinned when the front surface 11a is the mounting surface side of a circuit board or the like, and therefore the coil device itself can be made thin in the height direction of the circuit board or the like. It can be miniaturized. Therefore, when the magnetic core 10 with a gap according to the present embodiment is applied to electric and communication devices, etc., it can sufficiently meet the demand for high-density mounting accompanying miniaturization of electric and communication devices without sacrificing electromagnetic characteristics. It is possible to provide a compact magnetic core with a gap.

FIG. 3 is an external perspective view of a magnetic core 20 with a gap for a coil device according to a second embodiment of the present invention, and FIG. 4 is a sectional view taken along the line CC in FIG.

The magnetic core 20 with a gap has a substantially elliptical I-shaped magnetic cross section instead of a rectangular cross section between the inner surfaces of both leg tip ends 21a and 21b of a U-shaped magnetic core 21 having a rectangular cross section. The core 22 is combined with the gaps 23 on both end surfaces of the core 22 with a gap material (not shown) made of polyester film, glass, rubber or the like interposed therebetween. A coil 24 is wound around the outer periphery of the I-shaped magnetic core 22, and the thickness t22 of the I-shaped magnetic core 22 is 0.2 to the thickness t21 of the U-shaped magnetic core 21 as in the first embodiment. 0. The thickness is reduced to 8 times (0.5 times in this example). Further, the I-shaped magnetic core 22 is arranged at a position deviated in the thickness direction of the U-shaped magnetic core 21 so as not to project from the lower side surface 21a of the U-shaped magnetic core 21 in the thickness direction. By doing so, the same effect as that of the first embodiment can be obtained, and when the magnetic core 20 with a gap of the present embodiment is applied to an electric or communication device, the electromagnetic characteristics are not sacrificed. It is possible to provide a small-sized magnetic core with a gap that can sufficiently meet the demand for high-density packaging accompanying the miniaturization of electrical and communication equipment. The elliptical shape also has the advantage that the coil can be prevented from being broken even if the coil is wound directly there.

The cross-sectional shape of the I-shaped magnetic core with respect to the magnetic path is not limited to the quadrangular shape and the oblong shape in the above-described embodiment, and other similar shapes can be used.

In the above embodiment, the coil is wound directly on the I-shaped magnetic core, but the coil may be wound via a bobbin as in the conventional example. In this case, since the bobbin serves as a holding member for the I-shaped magnetic core, it is not necessary to use a gap material.

[0015]

[Effect of the device]

 According to the present invention described in detail above, in a coil device using a UI-shaped magnetic core, the thickness of the I-shaped magnetic core is made smaller than that of the U-shaped magnetic core, and the coil is wound around the winding portion. In addition, if the I-shaped magnetic core is offset and arranged in combination so that the I-shaped magnetic core does not protrude from the lower surface of the U-shaped magnetic core, the electromagnetic characteristics such as the inductor L and the impedance Z are sacrificed. Since it is possible to eliminate the amount of protrusion on one side of the coil or reduce it compared to the conventional one, it is possible to provide a magnetic core with a gap for a coil device that is downsized in the height direction. When this is mounted on a circuit board or the like, the entire device can be thinned.

[Brief description of drawings]

FIG. 1 is an external perspective view of a magnetic core with a gap according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line BB in FIG.

FIG. 3 is an external perspective view of a magnetic core with a gap according to a second embodiment of the present invention.

FIG. 4 is a sectional view taken along the line CC in FIG.

FIG. 5 is a front view of a conventional magnetic core with a gap.

6 is a cross-sectional view taken along the line AA in FIG.

[Explanation of symbols]

 10 Magnetic core with gap 11 U-shaped magnetic core 12 I-shaped magnetic core 13 Gap

Claims (3)

[Scope of utility model registration request] 1. A magnetic core with a gap in which an I-shaped magnetic core is arranged so that a magnetic path is formed between both legs of the U-shaped magnetic core through a gap, wherein the thickness of the I-shaped magnetic core is the U-shaped magnetic core. A magnetic core with a gap, wherein the magnetic core has a thickness smaller than that of the magnetic core, and the central position in the thickness direction of the I-shaped magnetic core is deviated from the central position in the thickness direction of the U-shaped magnetic core. 2. The magnetic core with a gap according to claim 1, wherein the thickness of the I-shaped magnetic core is set to 0.2 to 0.8 of the thickness of the U-shaped magnetic core. 3. The magnetic core with a gap according to claim 1, wherein a cross-sectional shape of the I-shaped magnetic core with respect to the magnetic path is an ellipse or a shape similar thereto.