JPH0456116A - Inductance part - Google Patents

Abstract

PURPOSE:To reduce loss in an inductance part by preparing gaps between the central magnetic leg of an E-shaped core, outer magnetic legs of the core, and bar type cores placed between the three magnetic legs so made as to have a structure which hardly generates eddy current. CONSTITUTION:Since between the central magnetic leg 5, outer magnetic legs 6, and bar type cores 2 gaps 4 are made, the gap size does not cause the height of an inductance part to change. Further, fluxes 7 that are generated in gaps 4 traverse the flat part of a conductive member 8 formed into a printed coil 3 at an angle close to the parallel direction, and further since multistage gaps are prepared, the structure of the inductance part is so made that it hardly generates eddy current and provides the effect of reducing the loss in the inductance part.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to inductance components such as transformers used in switching power supplies and the like.

Conventional technology Switching power supplies are becoming smaller and thinner by increasing the switching frequency, and inductance components such as transformers are beginning to use printed coils for their windings. Using printed coils has the advantage of being smaller and thinner, reducing loss due to the skin effect of the windings, and increasing the coupling between the primary and secondary coils, but on the other hand, the windings are flat-shaped. Therefore, the eddy current in the winding due to leakage magnetic flux near the gap increases,
The problem was that the losses were large.

Furthermore, in flyback power supplies, when the switching frequency is increased, the gap of the transformer increases, making it difficult to reduce the thickness of the transformer and increasing loss due to leakage magnetic flux.

Conventionally, this type of inductance component, particularly a transformer, has a structure as shown in FIGS. 10 and 13. FIG. 10 shows a transformer using a printed coil as a first conventional example, in which 21 is an E-type core, 22
is an I-shaped core, 23 is a printed coil, and 24 is a gap.

FIG. 11 is a sectional view of a main part showing the gap and winding structure in FIG. 10. FIG. 12 is an enlarged view of a main part for explaining the magnetic flux near the gap 24 in FIG. 11. 27 is a magnetic flux, and 28 is a conductor formed on the printed coil 23.

Figure 13 shows the second part of the transformer using printed coils.
31 and 32 are E-shaped cores, 33 are printed coils, and 34 are caps. A sectional view of the main part showing the cap and winding structure in FIG. 13 is shown in FIG. 14.
As shown in the figure.

FIG. 15 is an enlarged view of a main part for explaining the magnetic flux near the gap 34 in FIG. 14.

Problems to be Solved by the Invention In such a conventional configuration, FIGS. 10, 11,
In a case like the configuration of the first conventional example shown in Fig. 12, when increasing the switching frequency of the flyback type power supply, the gap of the transformer must be widened. This poses a problem in that it becomes a hindrance to making the transformer thinner.

Furthermore, in the case of the configuration of the second conventional example shown in FIGS. The magnetic flux 37 generated in the vicinity of the gap 34 because the direction is parallel to the plane part of the body 38 perpendicularly crosses the plane part of the conductor 38 formed in the printed coil 33, so that an eddy current is generated. However, there was a problem in that the loss caused by this eddy current was large.

In view of these problems, the present invention has been developed so that the size of the gap does not affect the height of the inductance component, making it easy to reduce the thickness of the inductance component.Furthermore, eddy currents are less likely to occur due to leakage magnetic flux generated near the gap, resulting in less loss. The company provides inductance components.

Means for Solving the Problem In order to solve this problem, the present invention arranges a rod-shaped core between the central magnetic leg of the E-shaped core and each outer magnetic leg, and The gap between the cores is used as a gap. Further, the structure is such that a cylindrical core is used as the bar-shaped core, or an integral core such as a U-shaped core or a 0-shaped core is used.

Effect: With this configuration, the height of the inductance component is independent of the gap (therefore, even when the gap is large, the inductance component can be made thin.Moreover, the gap surface is a flat part of the conductor formed on the printed coil). Since the leakage flux generated near the gap crosses the flat part of the conductor formed in the printed coil at an angle close to the parallel direction, the structure is such that eddy currents are difficult to generate in the winding. Furthermore, since the gap is multi-stage, the spread of leakage magnetic flux generated in the gap is reduced, and the eddy current generated by the leakage magnetic flux is reduced, reducing loss.Also, a cylindrical core is used as the rod-shaped core. As a result, the spread of leakage magnetic flux generated near the gap is smaller than when a rod-shaped core is used, and loss is reduced.

Example Embodiments of the present invention will be described below using a transformer as an example.

Embodiment 1 FIGS. 1, 2, and 3 show a first embodiment of the present invention. In FIG. 1, 1 is an E-shaped core, 2 is two rod-shaped cores, and 3 is a printed core. It is a coil of Figure 2 shows the first
FIG. 2 is a cross-sectional view of the transformer according to the first embodiment shown in the figure;
5 is a magnetic leg at the center of the E-type core 1, 6 is a magnetic leg on the outside of the E-type core 1, and 4 is between the magnetic leg 5 at the center of the E-type core 1, the outer magnetic leg 6, and the bar-shaped core 2. This is the gap created between Figure 3 shows
FIG. 3 is an enlarged view of the gap portion of the transformer according to the first embodiment. 8 is a conductor formed in the printed coil 3, and 7 is a magnetic flux generated in the gap 4.

According to this embodiment, the central magnetic leg 5, the outer magnetic leg 6,
Since there is a gap 4 between the rod-shaped core 2 and the gap 4, the height of the component does not change depending on the size of the gap. Furthermore, the magnetic flux 7 generated in the gap 4 crosses the flat part of the conductor 8 formed in the printed coil 3 at an angle close to the parallel direction, and furthermore, since a multi-stage gap is formed, the way the magnetic flux 7 spreads is The structure is small and makes it difficult for eddy currents to occur in the conductor 8, and the effect of reducing loss can also be obtained.

Embodiment 2 FIGS. 4, 5, and 6 show a second embodiment of the present invention. In FIG. 4, 11 is an E-shaped core, 12 is two cylindrical cores, and 13 is a printed core. It is a coil of FIG. 5 is a cross-sectional view of the transformer according to the second embodiment shown in FIG. This is a gap provided between the central magnetic leg 15 and the outer magnetic leg 16 of the mold core 1 and the cylindrical core 12. FIG. 6 is an enlarged view of the gap portion of the transformer according to the second embodiment. 18 is a conductor formed in the printed coil 13; 17 is a gap 14;
This is the magnetic flux generated in

According to this embodiment, by using the cylindrical core 12 as the rod core, the magnetic flux 17 generated in the gear and the knob 14 is
It is possible to further suppress the spread of the magnetic flux, and to reduce loss caused by magnetic flux.

Embodiment 3 A third embodiment of the present invention is shown in FIGS. 7 and 8,
In FIGS. 7 and 8, the same parts as those shown in FIG. 1 are designated by the same numbers, and the description thereof will be omitted. In this embodiment, a U-shaped core 18 and a U-shaped core 19 are used as the rod-shaped core, and in addition to the same effect as in the first embodiment, the core can be easily fixed.

Example 4 FIG. 9 shows the first example of the present invention. An example of the method of fixing the rod-shaped core in the second example is shown. Components that are the same as those shown in FIG. 1 are given the same reference numerals and their explanations will be omitted.

20 is a recess 21 into which the rod-shaped core 2 and the cylindrical core can fit.
This is a bobbin with a

According to this embodiment, since the rod-shaped core 2 can be fixed in common with the bobbin for fixing the winding, the rod-shaped core 2 can be easily fixed.

Note that the present invention is applicable not only to the transformer as in the above embodiment, but also to all inductance components using a core with a gap, such as a choke coil.

Effects of the Invention As described above, according to the present invention, in an inductance component composed of a core and a printed coil, a rod-shaped magnetic leg arranged between the central magnetic leg of the E-shaped core, the outer magnetic leg, and both magnetic legs is used. Since there is a gap between the inductance component and the core, the gap is unrelated to the height of the inductance component, and even when there is a large gap, it is possible to reduce the thickness. Since the gap surface of the core is arranged in a direction orthogonal to the plane part of the printed coil, the leakage magnetic flux near the gap is caused by directing the plane part of the conductor formed in the printed coil at an angle close to parallel. Since the structure is such that eddy currents are less likely to occur since they cross each other, it is possible to obtain the effect of reducing loss.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an inductance component according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the same, FIG. 3 is an enlarged view of a gap portion in FIG. 2, and FIG. FIG. 5 is a perspective view showing an inductance component according to an embodiment, FIG. 5 is a sectional view thereof, FIG. 6 is an enlarged view of a main part showing magnetic flux in the gap portion of FIG. 5, and FIG. FIG. 8 is a perspective view showing an inductance component according to a third embodiment of the present invention, FIG. 9 is a perspective view showing a method of fixing a rod-shaped core as a fourth embodiment, and FIG. 10 is a perspective view showing a method of fixing a rod-shaped core as a fourth embodiment. FIG. 11 is a perspective view showing an example of an inductance component, FIG. 11 is a sectional view thereof, and FIG. 12 is an enlarged view of a main part showing magnetic flux in the gap portion of FIG. 11. FIG. 13 is a perspective view showing an inductance component according to a second conventional example, FIG. 14 is a sectional view thereof, and FIG. 15 is an enlarged view of a main part showing magnetic flux in the cap portion of FIG. 14. 1.11... E-type core, 2... Rod-shaped core, 12... Cylindrical core, 3.13...
・Printed coil, 4.14...gap,
5.15... Central magnetic leg, 6, 16...
・Outer magnetic leg, 18... U-shaped core, 19...
...0-shaped core, 20...bobbin. Name of agent: Patent attorney Shigetaka Awano and one other person Funeral diagram No. 7- Fig. Kayu-ku 12/7 16 /// E type] T' Printed coil Fig. 10 Fig. 1i Fig. 1211m Fig. 13 Fig. 14 32 Figure

Claims (4)

[Claims] (1) Consisting of an E-shaped core, two rod-shaped cores, and a printed coil, the printed coil is arranged on the central magnetic leg of the E-shaped core, and the printed coil is arranged on the central magnetic leg of the E-shaped core and each An inductance component in which the two rod-shaped cores are arranged between the outer magnetic legs, and a gap is formed between the central magnetic leg of the E-shaped core, the outer magnetic legs, and the rod-shaped core. (2) The inductance component according to claim 1, wherein a cylindrical core is used as the rod core. (3) The inductance component according to claim 1, wherein an integrated core such as a U-shaped core or an O-shaped core is used as the two rod-shaped cores. (4) The inductance component according to claim 1, wherein the rod-shaped core is fixed using a bobbin provided with a recess into which the rod-shaped core can be fitted.