JPH0485906A - E-type core - Google Patents

Abstract

PURPOSE:To obtain an E-type core, which prevents a magnetic saturation and of which working accuracy is decreased by making the width of a yoke part larger than that of a side magnetic leg and by dividing at least one E-type surface into plural parts along the central part of a groove provided between the central magnetic leg and side magnetic leg. CONSTITUTION:A central magnetic leg cutting part 61a and a yoke cutting part 61b are formed on the same surface by a cutting work, while the relation between the width W1 of the central magnetic leg cutting part 61a and width W4 of the yoke cutting part 61b is set to W1<W4, and other notches 60 are cut to almost the central part of first groove 56 and second groove 57 in a part where W1 is subtracted from W4. Also, the relation between the width W2 of a first side magnetic leg 53 or second side magnetic leg 54 and width W3 of a yoke part 55 is set to W2<W3.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an E-type core made of a magnetic material used as a magnetic core of transformers, choke coils, noise filters, etc. The present invention relates to an E-type core that allows transformers and the like to be miniaturized by incorporating the E-type core whose structure has been designed to make effective use of the structure.

(Prior Art) In recent years, there has been an increasing demand for smaller electronic devices, and in particular, there is a demand for thin and lightweight electronic devices that can be carried and used outdoors or indoors.

Therefore, it is desired that the transformers, choke coils, noise filters, etc. used in these electronic devices be made smaller and lighter.

Therefore, there is a strong demand for thinner and lighter cores made of magnetic materials used as magnetic cores in transformers, choke coils, noise filters, etc., and various proposals have been made to date. .

An E-type core is generally used as a magnetic core incorporated in the transformer, etc., and a conventional example of the E-type core will be described with reference to FIG.

The E-type core l is made of a magnetic material such as ferrite.

On both sides of the central magnetic leg 2 having a substantially square cross section, first
A pair of first side magnetic legs 3 and a pair of second side magnetic legs 4 are disposed with a groove 6 and a second groove 7.

One end of each of the central magnetic leg 2, the first side magnetic leg 3, and the second side magnetic leg 4 is connected by a yoke portion 5.

At this time, the other end surfaces of the central magnetic leg 2, the first side magnetic leg 3, and the second side magnetic leg 4 are formed on the same plane, and the E
In order to optimize the magnetic properties of the mold core l, the central magnetic leg 2
The cross-sectional area is equal to the sum of the cross-sectional areas of the first side magnetic leg 3 and the second side magnetic leg 4.

When incorporating the E-type core l into a transformer or the like, a coil bobbin 8 made of a coil or the like wound with enameled wire or the like is fitted onto the central magnetic leg 2, as shown by the imaginary line in the figure. Furthermore, the E plastic molding is combined with the type 1 core and fixed with a fixing fitting or the like (not shown).

When the coil bobbin 8 is fitted into the E-shaped core 1 as described above, the upper and lower windings of the coil bobbin 8 are
The central magnetic leg 2 of the E-type core 1 protrudes by two widths from the upper and lower surfaces, so the dimensions of each part are not effectively utilized in the structural design of the E-type core 1, and moreover, the transformer etc. cannot be used on an electronic circuit board, etc. There were problems such as poor stability during installation.

Therefore, while satisfying the condition that the cross-sectional area of the central magnetic leg is equal to the sum of the cross-sectional areas of the first side magnetic leg and the second side magnetic leg, E
A conventional example in which a transformer or the like in which the E-type core is incorporated is downsized by performing a structural design that effectively utilizes the dimensions of each part of the type core will be described with reference to FIG.

In the E-type core 11, a central magnetic leg 12 elongated in the horizontal direction extends from the lower center of the front surface of the yoke portion 15, and a first groove 16 and a second groove are formed on both sides of the central magnetic leg 12. 17, the first side magnetic leg 13 and the second side magnetic leg 14 are arranged,
One end of each of the first side magnetic leg 13 and the second side magnetic leg 14 is connected by the yoke portion 15.

Further, the E-shaped core l] has the center magnetic leg [2], the other end surfaces of the first side magnetic leg 13 and the second side magnetic leg 14 being formed on the same plane, and the center magnetic leg [1]2[deg.]. l [112, first side magnetic leg 13
The lower surfaces of the second side magnetic legs 14 are formed on the same surface.

A coil bobbin 18 is fitted into the central magnetic leg 12 of the E-shaped core 11, as shown by imaginary lines in the figure, and constitutes a coil by winding an enameled wire or the like.

Further, by combining with an E-type or I-type core having the same structure as the E-type core 11, a transformer or the like is formed.

According to the E-shaped core 11, the central magnetic leg 12 is elongated in the lateral direction, and has a height larger than that of the first side magnetic leg 13, the second side magnetic leg 14, and the yoke part 15. Central magnetic leg 1
2, the upper winding portion of the coil bobbin 18 fitted on the central magnetic leg 12 is more secure than the inner walls of the first side magnetic leg 13, the second side magnetic leg 14, and the yoke portion 15. There is no protrusion, and the structure is designed to accommodate miniaturization of the E-shaped core 1.

The E-shaped core 11 is molded, for example, by press-molding a magnetic material using a double-acting press device (not shown) having a plurality of pressurizing surfaces.

According to the above-mentioned double-acting type press device, since each pressurizing surface works in a double manner to pressurize the magnetic material, it is difficult to mold the magnetic material to have a uniform density. There was a risk that microcracks or the like would occur in the E-shaped core 11 due to internal stress during the double-acting pressurization.

Further, the double-acting press device is large, has complicated operation control, and has a slow molding speed, so it is not suitable for mass production.

For this reason, a method of manufacturing an E-type core as shown in FIGS. 5(a) to 5(d) has been proposed.

According to this method, a magnetic material is molded into a molded member 28 using a single-acting press device (not shown).
The molded member 28 is cut with cutting grooves 27a and 2, for example, using a lathe or the like.
7b is cut (FIG. 7(b)).

Next, the molded member 28 is sequentially cut to a predetermined width (see FIG.
C)), by cutting the approximately central upper part of the cut piece, the first side magnetic leg 23 and the second side magnetic leg 24 are arranged and formed on both sides of the central magnetic leg 22, and the central magnetic leg 22 is , an E-shaped core 21 is manufactured in which a yoke portion 25 connecting one end of each of the first side magnetic leg 23 and the second side magnetic leg 24 is formed.

A cutting groove portion 26 is formed in the E-air core 21 by cutting, in which the central magnetic leg cutting portion 26a and the yoke portion cutting portion 26b form the same surface, and the width of the yoke portion cutting portion 26b of the cutting groove portion 26 is W4' is the width W of the central magnetic leg cutting part 26a
1 ′, and the yoke portion cutting portion 2
Generally, all the notches 30 were formed on both sides of the 6b.

A coil bobbin (not shown) is fitted into the central magnetic leg 22 of the E empty core 21, and is combined with other E-type or I-type cores to form an L lance, etc. Ru.

At this time, since the cutting groove portion 26 is formed, the height Hl of the central magnetic leg 22 is increased as shown in FIG.
However, the height H of the first side magnetic leg 23 and the second side magnetic leg 24 is
2', F(1'<H2'). Therefore, the upper winding portion of the coil bobbin is prevented from protruding from the upper surface of the first side magnetic leg 23 and the second side magnetic leg 24. This contributed to stable mounting on electronic circuit boards, etc., as well as smaller size and lower profile.

According to the method for manufacturing the E-empty core described above, it is not necessary to use the double-acting type brace device 35, and the E-empty core 41 can be manufactured using a simple device and process.

Further, as shown in FIG. 7, the E-shaped core 31 having a different shape from the E-shaped core 21 is located at the center! A pair of first side magnetic legs 33 and second side magnetic legs 34 are arranged on both sides of #g32, each having cutting grooves 37a and 37b, and the central magnetic legs 32, first side magnetic legs 33, and One end of each of the 211111&n legs 34 is connected by a yoke portion 35.

Further, in the E-air core 31, the upper surface of the central magnetic leg 32 is cut to a height I (l'), and the yoke portion 35
is cut to have a tapered portion 40 at a height H3' which is higher than the height Hl, thereby forming a cutting groove portion 36.

In the cut groove portion 36 of the E-empty core 31, the upper surface of the central magnetic leg 32 and the cut upper surface of the yoke portion 35 were not on the same plane.

Note that when iron powder is used as the magnetic material, a powder magnetic core is formed by pressure molding, and when ferrite powder is used, a binder is added to the ferrite powder and granulated. A ferrite core is formed by pressure molding and further firing.

(Problem to be Solved by the Invention) However, according to the above-mentioned conventional E-air core, the width W1' of the central magnetic leg cut part and the width W4' of the yoke part cut part are W
By having the relationship l'<W4', all the notches are formed in the yoke part, and the width W2' of the ]th side magnetic leg and the second side magnetic leg and the width W3' of the yoke part are approximately W2. '
=W3', the cross-sectional area of the entire notch becomes smaller than the cross-sectional area of the first side magnetic leg and the second side magnetic leg, so that the cross-sectional area of the first side magnetic leg and the second side magnetic leg Because the relationship in which the sum of the cross-sectional areas is equal to the cross-sectional area of the central magnetic leg cannot be maintained, if a high load is not applied to the transformer etc. in which the E-empty core is incorporated, magnetic saturation will occur in all the notches. There was a problem that the desired characteristics could not be obtained.

In addition, in order to avoid magnetic saturation due to all the notches,
When the central magnetic leg and the yoke are cut so that Wl' and W4' are in the relationship Wl'=W4, the upper surface of the central magnetic leg may be slightly shifted due to the cutting process. Since convex portions that are not cut remain and a defective appearance occurs, there is a problem in that the cutting requires high processing precision and the working efficiency is poor.

The present invention has been made in view of the above circumstances, and it prevents magnetic saturation due to small cross-sectional areas due to the formation of all notches, and also eases processing accuracy by widening all the notches. This provides an E-type core.

(Means for Solving the Problem) In order to achieve the above object, the present invention includes a central magnetic leg,
An E-shaped core having a pair of side magnetic legs arranged opposite to each other so as to sandwich the central magnetic leg, and a yoke portion that connects one end of the central magnetic leg and one end of each of the pair of side magnetic legs to each other. , the width of the yoke portion is made wider than the width of the side magnetic legs, and at least one E-shaped surface of the E-shaped core is formed into a groove provided between the central magnetic leg and the side magnetic legs. By processing it so that it is divided into multiple parts along the center part.

This aims to achieve the above objectives.

(Function) In the present invention, by making the width of the yoke portion of the E-shaped core wider than the width of the side magnetic leg, the cross-sectional area of the first side magnetic leg or the second (Ill) magnetic leg and the yoke Even if a high load is applied to a transformer, etc. in which the E-type core is incorporated, magnetic saturation will occur in all the notches. can be prevented.

Furthermore, since the E-shaped surface of at least one of the E-shaped cores is processed so as to be divided into a plurality of parts along the center of the groove provided between the central magnetic leg and the side magnetic leg, cutting Even if the notch position is slightly shifted during machining, there is no fear that a convex portion that is not cut will remain on the upper surface of the central magnetic leg, and it is possible to prevent appearance defects.

(Example) Embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a perspective view showing an embodiment of an E-type core according to the present invention, FIG. 2(a) is a plan view showing an E-type core of the same embodiment, and FIG. A cross-sectional view showing the XX section of the mold core is shown.

The E-type core 51 shown in FIG. 1 is manufactured by the following steps.

Magnetic material is connected to a pair of side columns using a single-acting press device,
It is molded into a day-shaped molded member having a pair of common columns that connect both ends of the side columns, and a central common column that connects the center portions of the pair of side columns.

Along the central common column of the day-shaped molded member, the surfaces of the pair of side columns and the central common column are cut using a disk-shaped grinder made of an abrasive material or the like.

At this time, the cutting width is wider than the width of the central common column and the cutting depth is determined by the installed height of the rotary shaft to which the disc-shaped grinder is attached.

Further, since the press surface of the single-acting press device is flat-processed, the upper and lower surfaces of the pair of side columns, the pair of common columns, and the central common column of the day molded member form the same surface. are doing.

Next, a pair of E-shaped cores are manufactured by cutting the pair of common columns and the central common column of the day-shaped molded member approximately at the center.

In the E-type core 51 manufactured as described above, as shown in FIG. 1, the central magnetic leg cut portion 61a formed by the cutting process and the yoke portion cut portion 61b are on the same plane. Also, between the width W1 of the central magnetic leg cut portion 61a and the width W4 of the yoke portion cut portion 61b, Wl<W4.
There is a relationship as follows, and the portion obtained by subtracting Wl from W4 becomes a full notch portion 60 that is cut to approximately the center of the first groove 56 and second groove 57.

In addition, in the E-type core 51, as can be seen with reference to FIG. , the relationship between
As W2<W3, the yoke portion 55 is connected to the first side magnetic leg 53.
It is also wider than the second side magnetic leg 54.

At this time, the cross-sectional area of the central magnetic leg 52 is the same as that of the first side magnetic leg 53.
and the cross-sectional area of the second side magnetic leg 54, and the cross-sectional area of all the left and right notches 60 of the yoke portion 55.

That is, when cutting the central magnetic leg 52 and the yoke part 55, an extra notch 60 is generated in the yoke part 55, but due to the relationship W2<W3, the first side magnetic leg 53 or the second side magnetic leg The E-shaped core 51 is configured such that the cross-sectional area of the side magnetic leg 54 and the cross-sectional area of the yoke portion 55 in the entire notch 60 are equal to -.

According to the E-type core 51 configured as described above, the width W1 of the central magnetic leg cut portion in the cut groove portion of the E-type core and the width W4 of the yoke portion cut portion have a relationship of Wl<W4. ,
Furthermore, the width of all left and right notches is obtained by subtracting Wl from W4.
By cutting the width of the first groove and the second groove provided on both sides of the central magnetic leg to approximately 1/2, even if the notch position shifts slightly during the cutting process, , it is possible to prevent a convex portion that is not cut from remaining on the upper surface of the central magnetic leg.

Further, the width W1 of the central magnetic leg cut portion and the width W4 of the yoke portion cut portion have a relationship of Wl<W4, so that all the notches are formed on the yoke portion. Since the width W2 of the side magnetic leg or the second side magnetic leg and the width W3 of the central magnetic leg have the relationship W2<Wl, the disconnection of the first side magnetic leg or the second side magnetic leg is Since the area and the cross-sectional area of all the notches of the yoke portion are equal to each other, magnetic saturation in all the notches can be avoided.

Further, in the E-shaped core 51, as shown in FIG. 2(b), the cross-sectional area of the central magnetic leg 52 is twice the cross-sectional area of the first side magnetic leg 53 and the second side magnetic leg 54. At the same time, the height Hl of the central magnetic leg 52 is higher than that of the first side magnetic leg 53 and the second side magnetic leg 5.
It is formed to have a lower height than the height H2 of No. 4.

That is, a coil bobbin 65 (represented by a virtual line) composed of a coil or the like wound with enameled wire or the like is attached to the central magnetic leg 5.
2, one winding portion of the coil bobbin does not protrude above the height H2 of the first side magnetic leg 53 and the second side magnetic leg 54.

Therefore, the E-shaped core 51 to which the coil bobbin is attached can stably mount a transformer or the like incorporated together with other E-shaped or I-shaped cores on an electronic circuit board or the like.

In addition, when iron powder is applied to the magnetic material, a powder magnetic core is formed by pressure molding, and when ferrite powder is applied, a binder is added to the ferrite powder to granulate it, A ferrite core is formed by pressure molding and further firing.

(Effects of the Invention) Since the E-type core according to the present invention is configured as described above, it has the following effects.

(1) The width W1 of the cut part of the central magnetic leg in the cut groove part of the E-type core and the width W4 of the cut part of the yoke part have the relationship Wl<W4, and furthermore, the left and right margins obtained by subtracting Wl from W4 Since the notch width is cut to approximately 1/2 of the width of the 111th and second grooves provided on both sides of the central magnetic leg, the notch position may be slightly shifted during the cutting process. However, there is no risk of leaving an uncut convex part on the top surface of the central magnetic leg (,
In addition to being able to prevent appearance defects, the cutting process does not require high machining accuracy, so it has the excellent effect of improving work efficiency.

(2) Furthermore, the width Wl of the central magnetic leg cut portion and the width W4 of the yoke portion cut portion have a relationship of Wl<W4, so that all the notches are formed on the yoke portion. ,
Since the width W2 of the first side magnetic leg or the second side magnetic leg and the width W3 of the central magnetic leg have a relationship of W2<Wl, the first side magnetic leg or the second side magnetic leg The cross-sectional area of the yoke portion and the cross-sectional area of the entire notch of the yoke portion are equal to each other. It has the excellent effect that magnetic saturation can be prevented from occurring in the E-type core, and desired characteristics can be obtained in a transformer or the like in which the E-type core is incorporated.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of an E-type core according to the present invention, and FIG. 2(a) is a second plan view showing an E-type core of the same embodiment.
b) is a cross-sectional view showing the XX cross section of the E-type core of the same example, FIGS. 3 and 4 are perspective views showing the conventional E-type core, and FIGS. 5(a) to (d) are the conventional E-type cores. 6 is a cross-sectional view showing a partially cut-out cross section of the conventional example, and FIG. 7 is a cross-sectional view showing a partially cut-away cross-section of another conventional example. It is a diagram. 51... E-type core, 52... Central magnetic leg, 53...
... 1st side magnetic leg, 54... 2nd side magnetic leg, 55...
Yoke part, 56...first groove, 57...second groove 60...excess notch part, 61...cutting groove part. Fig. 1 51...E-type core 52...Central magnetic leg 53...First side F1111II1 54...Second side magnetic leg 55...Yoke portion 56...First section 57...・Second Man 60... Extra Notch Edict 61... Cutting Groove Evil [Second E] Figure (C) (d) Figure F) Figure 1 (a) Figure

Claims (1)

[Claims] (1) A central magnetic leg, a pair of side magnetic legs arranged opposite to each other so as to sandwich the central magnetic leg, and a yoke portion that connects one end of the central magnetic leg and one end of each of the pair of side magnetic legs to each other. In the E-shaped core, the width of the yoke portion is made wider than the width of the side magnetic legs, and at least one E-shaped surface of the E-shaped core is connected to the central magnetic leg and the side magnetic leg. An E-type core characterized in that it is processed to be divided into a plurality of parts along the center of a groove provided between the two.