JP2001223122A - Leakage flux type high-frequency transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To regulate a secondary winding continuously in leakage inductance in a leakage flux type high-frequency transformer without changing a spacer in thickness, where the high-frequency transformer is equipped with an E-type core, an I-type core, and the spacer provided at a joint surface between the E-type core and the I-type core. SOLUTION: The length of an I-type core 2 is slightly larger than the width of an E-type core 1, a sloping plane 3 or a cut part 4 with a curved plane is provided to the side of the I-type core 2 confronting the E-type core 1, and a gap 8 formed between the sloping plane 3 and the middle leg 1B of the E-type core 1 is regulated in relative width by parallel displacing either the E-type core 1 or the I-type core 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leakage magnetic flux type high frequency transformer.

[0002]

2. Description of the Related Art As shown in FIG. 4, for example, a conventional leakage magnetic flux type high frequency transformer includes a ferrite core 1 having an E-shaped cross section (hereinafter referred to as an E-shaped core) and a ferrite core having an I-shaped cross section. A primary winding 3 and a secondary winding 4 are wound around both legs of an E-type core 1 using a core (hereinafter referred to as an I-type core) 2, and the E-type core 1 and the I-type core 2 This is a structure in which a closed magnetic path is formed by sandwiching an insulating spacer 5 at the joint.

[0003]

In this structure, the adjustment of the leakage inductance on the secondary winding 4 side changes the width of the gap 6 formed between the middle leg of the E-type core 1 and the I-type core 2. This is done by: In order to change the width of the gap 6, it is necessary to change the thickness of the spacer 5.
However, if the thickness of the spacer 5 is changed, the coupling coefficient between the primary winding 3 and the secondary winding 4 changes accordingly. Also, in the above configuration, in order to adjust the leakage inductance of each transformer to a constant value, a number of spacers having different thicknesses are prepared, and a spacer having a thickness matching the predetermined leakage inductance is mounted in the assembly process. There must be. Therefore, the working efficiency in the transformer assembling process is low, and various types of spacers having different thicknesses must be prepared, which is uneconomical. Further, since the thickness of the spacer is different in each transformer, there is a quality problem that the height of the transformer cannot be made uniform.

[0004]

According to a first aspect of the present invention, a closed magnetic path is formed with a spacer interposed between a joint of a side leg of an E-shaped core and an I-shaped core, and In a high-frequency transformer of a leakage magnetic flux type in which a gap is formed between the center leg of the core and the opposite side of the I-type core, the surface of the I-type core slightly longer than the width of the E-type core is opposed to the surface of the I-type core. An inclined surface or a curved surface is formed by cutting or projecting, and a gap width can be continuously changed along the inclined surface or the curved surface. With such a configuration, the gap width can be continuously changed without changing the thickness of the insulating spacer interposed between the junctions of the E-type core and the I-type core. A second aspect of the present invention is characterized in that the inclination angle or the curvature of the curved surface formed on the cutting portion or the protruding portion is formed asymmetrically with respect to the longitudinal direction of the I-shaped core. With such a configuration, it is possible to easily adjust the leakage inductance.

[0005]

1A and 1B are views for explaining an embodiment of the high-frequency transformer of the present invention. FIG. 1A is a sectional side view, FIG. 1B is a perspective view of a core used in FIG. Is a view showing another embodiment, (a) is a cross-sectional side view, (b) is FIG. 2 (a)
FIG. 3 is a view showing still another embodiment, FIG. 3 (a) is a sectional side view, and FIG. 3 (b) is a perspective view of the core used in FIG. 3 (a). 1 to 3, the same portions will be described with the same reference numerals. Reference numeral 1 denotes an E-shaped core made of ferrite, which has a middle leg 1B located at a central portion between the side legs 1A and 1A 'and the side legs. Reference numeral 2 denotes an I-shaped core having a width longer than the width a of the E-shaped core 1. The portion of the E-shaped core 1 facing the side legs 1A, 1A 'and the middle leg 1B is cut obliquely near the center in the longitudinal direction. A cutting portion 4 having a surface 3 is formed. 5 is an E-shaped core side leg 1A, 1A '
An insulating spacer sandwiched between the joining surfaces of the E-shaped core 1 and the I-shaped core 2; a primary winding 6 attached to the side leg 1A of the E-shaped core 1;
7 is a secondary winding attached to the side leg 1A 'of the E-shaped core 1, 8
Is a gap formed between the inclined surface 3 formed on the cutting portion 4 of the I-shaped core 2 and the middle leg 1B of the E-shaped core 1.

FIG. 2 shows another embodiment of the present invention, in which the inclination angle of the inclined surface 3 provided on the I-shaped core 2 is formed to be asymmetrical with respect to the longitudinal direction of the I-shaped core. FIG. 3 shows still another embodiment, in which an I-shaped core 2
A projection 4 'projecting toward the middle leg 1B of the E-shaped core 1 at a portion corresponding to the cutting portion, and a gap 8 formed between the projection and the middle leg 1B of the E-shaped core 1. Is adjusted along the curved surface 3 'of the protrusion 4'.

[0007]

In the above configuration, the adjustment of the leakage inductance L on the secondary winding 7 side is performed by moving one of the E-type core 1 and the I-type core 2 to the right or left in parallel. For example, in the embodiment of FIG. 1, when the E-shaped core 1 is moved to the left, a gap 8 formed between the inclined surface 3 of the cutting portion 4 formed on the I-shaped core 2 and the middle leg 1B of the E-shaped core. , The relative inductance becomes smaller, so that the leakage inductance L
Becomes larger. Conversely, when the E-shaped core 1 is moved to the right, the relative width of the gap 8 increases, so that the leakage inductance L decreases.

[0008]

As described above, the transformer according to the present invention comprises the spacer 5 sandwiched between the junctions of the E-type core 1 or the I-type core 2.
E-type core 1 or I-type core 2 without changing the thickness of
Can be continuously adjusted only by moving one of them in parallel, so that the coupling coefficient between the primary winding 6 and the secondary winding 7 is kept constant. Next winding 6
The adjustment of the side leakage inductance L can be easily performed. Further, as described above, since the thickness of the spacer 5 does not need to be changed, the height dimensions of the individual transformers can be made the same.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an embodiment of the high-frequency transformer of the present invention,

FIG. 2 is an explanatory view showing another embodiment,

FIG. 3 is an explanatory view showing still another embodiment,

FIG. 4 is a cross-sectional view of a conventional leakage flux type high frequency transformer,

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... E type core 1A, 1A '... Side leg 1B ... Middle leg 2 ... I type core 3 ... Inclined surface 3' ... Curved surface 4 ... Cutting part 4 '... Projection part 5 ... Spacer 6 Primary winding 7 Secondary winding 8 Gap

Claims (2)

[Claims] 1. A closed magnetic path is formed at a joint between a side leg of an E-shaped core and an I-shaped core with a spacer interposed therebetween, and
In a high-frequency transformer of a leakage magnetic flux type having a gap formed between the middle leg of the E-type core and the opposite side of the I-type core, the high-frequency transformer faces the middle leg of the I-type core slightly longer than the width of the E-type core. A magnetic flux leakage type high frequency transformer characterized in that an inclined surface or a curved surface is formed by cutting or projecting a surface to be formed, and a gap width can be continuously changed along the inclined surface or the curved surface. 2. The leakage according to claim 1, wherein the inclination angle of the inclined surface formed on the cutting portion or the projecting portion or the curvature of the curved surface is formed asymmetrically with respect to the longitudinal direction of the I-shaped core. Magnetic flux type high frequency transformer.