JPH0488611A - E-shaped core - Google Patents

Abstract

PURPOSE:To prevent the reduction of cross-sectional area of the complementary notched part of a yoke section, and also to prevent occurrence of magnetic saturation by a method wherein the width of the yoke section of an E-shaped core is made wider than the width of magnetic legs. CONSTITUTION:The width of the yoke part 55 of an E-shaped core 51 is made wider than the width of side magnetic legs 53 and 54, and both E-type surfaces of the core 51 are divided into a plurality of parts along the side magnetic leg parts 53 and 54. On the E-shaped core 51, the center magnetic leg cut part 61a of the groove section 61 formed by cutting and the yoke cut part 61b are positioned on the same surface, and as the upper and lower surfaces of the E-shaped surface of the E-shaped core 51 are cut using a disc-shaped grinder, first side magnetic leg notched parts 63a and 63b having a width of W5 and second side magnetic leg notched parts 64a and 64b are formed respectively on the first side magnetic leg 53 and the second side magnetic leg 54. At this time, a relation of W1<W4 is formed between the width W1 of the center magnetic leg cut part 61a and the width of W4 of the yoke cut part 61b, and the left and right positions obtained by dividing W1 from W4 become the complementary notched part 60.

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. This relates to the E-type core, which has a structural design that makes effective use of it.

(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, there is a strong demand for smaller and lighter transformers, choke coils, noise filters, and the like used in these electronic devices.

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 made of a magnetic material such as ferrite has a first groove 6 and a second groove 2117 on both sides of the central magnetic leg 2 having a substantially square cross section, respectively. 2
The side Mi legs 4 are arranged, and the central magnetic legs 2 and the first
One end of each of the 11111 magnetic leg 3 and the second side magnetic leg 4 is connected by a yoke portion 5.

At this time, the central magnetic leg 2, the first side magnetic leg 3, and the second side magnetic leg!
The other end surface of 114 is formed on the same plane, and in order to optimize the magnetic properties of the E-shaped core 1, the cross-sectional area of the central magnetic leg 2 is the same as that of the first (!1111m leg 3 and the second Side M
It is formed to be equal to the sum of the cross-sectional areas of i#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 I-shaped core and fixed with a fixing fitting or the like (not shown).

When the coil bobbin 8 is fitted into the front EE type cocoa, the upper and lower parts of the winding of the coil bobbin 8 protrude by two widths from the upper and lower surfaces of the central magnetic leg 2 of the E type core l, so that It could not be said that the dimensions of each part were effectively utilized in the structural design.

Moreover, when the transformer or the like is mounted on an electronic circuit board or the like, the protruding two-width winding portion serves as the mounting portion on the board or the like, resulting in problems such as poor stability.

Therefore, the cross-sectional area of the central magnetic leg is
While satisfying the condition that it is equal to the sum of the cross-sectional areas of the side magnetic legs,
An E-type core has been devised with a structural design that makes effective use of the dimensions of each part, and this E-type core will be explained with reference to FIG. 10.

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, a first side magnetic leg 13 and a 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 11 is located at the center [! 11!112° The other end surfaces of the first side magnetic leg 13 and the second side magnetic leg 14 are formed on the same plane, and the central magnetic leg 12° and the first side magnetic leg 1
3 and the lower surfaces of the second side magnetic legs 14 are formed on the same plane.

A coil bobbin 18 is fitted into the central magnetic leg 12 of the E-type core 11, as shown by the imaginary line in the figure, and when combined with an E-type or I-type core, a transformer etc. It is beginning to form.

According to the E-shaped core 11, the central magnetic leg 12 is elongated in the lateral direction, so that the height of the central magnetic leg 12 is
The height of the 1111B leg 13, the second side magnetic leg 14, and the yoke portion 15 is low, so that the central magnetic! 11
112, and the central magnetic leg 1 has a space above it.
The upper winding part of the coil bobbin 18 fitted in the first side magnetic leg 13 and the second side magnetic leg I! 14 and the upper surface of the yoke part 15 2. Therefore, the E-shaped core 11
The structure has been designed to accommodate miniaturization.

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

According to the above-mentioned double-acting type press device, each pressurizing surface operates in a double manner to pressurize the magnetic material, so it is difficult to mold the magnetic material so that it has 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 double-acting pressurization.

Furthermore, the double-acting press device is large, has complicated operation control, and has a slow molding speed, making it unsuitable for mass production.

For this reason, a method of manufacturing an E-type core as shown in FIGS. 11(a) to 11(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).
Cutting grooves 27a, 2 are formed in the molded member 28 using a lathe or the like, for example.
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 edge 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 leg 22,
E-shaped core 21 in which a yoke portion 25 connecting one end of each of the first flIIIFin leg 23 and the second side magnetic leg 24 is formed.
is manufactured.

A cutting groove 26 is formed in the E-shaped core 21 by cutting, in which the central magnetic leg cutting part 26a and the yoke cutting part 26b are flush with each other, and the width of the yoke cutting part 26b of the cutting groove 26 is Generally, W4' is formed wider than W1' of the central magnetic leg cutting part 26a, and large thread cutting parts 30 are formed on both sides of the yoke part cutting part 26b.

The E-type core 21 has a coil bobbin (not shown) fitted into the central magnetic leg 22, and is combined with other E-type or 1-type cores to form a transformer or the like. .

At this time, since the cutting groove portion 26 is formed, the height H of the front central magnetic leg 22 is increased as shown in FIG.
1' is H1'<H2 with respect to the height 82' of the first side magnetic leg 23 and the second side magnetic leg 24. Therefore, the upper winding portion of the coil bobbin is This prevents the legs 23 and the second side magnetic legs 24 from protruding from the upper surface, contributing to stable mounting on an electronic circuit board, etc., and to a reduction in size and height.

According to the method for manufacturing the E-type core described above, there is no need to use the double-acting press device, and the E-type core 21 can be manufactured using common equipment and processes.

Further, as shown in FIG. 13, the E-type core 31 having a different shape from the E-type core 21 has a central magnetic field 1Ii1132.
A pair of first side magnetic legs 33 and second side magnetic legs 34 are arranged on both sides of the central magnetic leg 32, the first side magnetic legs 33, and the second side magnetic legs 34 having cutting grooves 37a and 37b, respectively. Side magnetic leg 3
4 are connected at one end by a yoke portion 35.

Further, in the E-type core 31 described in 51I'il, the upper surface of the central magnetic leg 32 is cut to a height H1', and the yoke portion 35 is cut to a height 83 which is higher than the height H1'.
' is machined with a tapered part 40 to form the cutting groove part 3.
6 is formed.

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

Further, as shown in FIG. 14, the E-type core 4I has cutting grooves 47a and 47b on both sides of the central magnetic leg 42, and a pair of first side magnetic legs 43 and second side magnetic legs 44 are arranged. At the same time, one end of each of the central magnetic leg 42, the first steel magnetic leg 43, and the second side magnetic leg 44 is connected by a yoke portion 45.

Furthermore, in the E-shaped core 41, the central magnetic leg 42
The upper and lower surfaces of are cut to a height H1', and the yoke portion 45 has a height H4' which is higher than the height H1'.
The cutting groove portion 46.4 is machined with the tapered portion 50.
6b is formed.

The surfaces of the cut grooves 4.6a and 46b of the E-shaped core 41 were not formed on the same plane as the upper and lower surfaces of the cut central magnetic leg 42.

(Problem to be Solved by the Invention) However, according to the above-mentioned conventional E-type core, the width Wl' of the central magnetic leg cut part and the width W4' of the yoke part cut part are
By having the relationship l'<W4', a large thread cutting portion is formed in the yoke part, and the width W2' of the first side magnetic leg and the second side magnetic leg and the radius W3' of the yoke part are approximately W2'
By having the relationship =W3', the cross-sectional area of the large thread cutting portion becomes smaller than the cross-sectional areas of the first side magnetic leg and the second side magnetic leg, so that the first side magnetic leg and the second side magnetic leg The relationship in which the sum of the cross-sectional areas of There is a problem in that magnetic saturation occurs below the characteristic value of the transformer, and as a result, the desired characteristics of the transformer etc. cannot be obtained.

In addition, in order to avoid magnetic saturation due to the thread cutting portion,
Even if the central magnetic leg and yoke portion are cut so that W1 and W4' have a relationship such that W1'=W4',
Due to a slight deviation in the notch position during the cutting process, a convex portion that is not cut remains on the surface of the central magnetic leg, resulting in a poor appearance, so the cutting process requires high precision. .

There was a problem in that working efficiency was reduced due to the processing accuracy.

Furthermore, when assembling a transformer or the like by fitting a coil bobbin into the central magnetic leg of the E-shaped core, internal stress concentrates at the connecting portion between the central magnetic leg and the yoke portion during the assembly process. There is a problem in that the connecting portion or the like may be damaged.

Furthermore, in the assembly process of attaching a coil bobbin to the E-type core and assembling a transformer, etc., there was a problem that the coil bobbin was only fitted in the center 1a111 and was not temporarily fixed, which caused problems in the assembly. .

The present invention has been made in view of the above-mentioned circumstances, and it is possible to prevent saturation below a predetermined characteristic value due to a reduction in the cross-sectional area of the large thread-trimming part, and to improve processing accuracy by widening the large thread-trimming part. The purpose of the present invention is to provide an E-type core which can be reliably assembled without fear of damaging connecting parts such as central magnetic legs during the assembly process of transformers and the like.

(Means for Solving the Problem) In order to achieve the above object, the present invention includes a central magnetic leg,
A pair of side magnetic legs arranged opposite to each other so as to sandwich the central magnetic leg, and the center 1B! One end of 1111 and the previous word - opposite side I
In the E-type core, the yoke part is made wider than the width of the side magnetic leg, and the radius of the yoke part is made wider than the width of the side magnetic leg.
Place the mold surface on that side Fi! The above object is achieved by dividing into a plurality of parts along the 111111 section.

(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 first side magnetic leg or the second side la! By preventing the cross-sectional area of the large thread-cutting portion of the yoke portion from becoming smaller than the cross-sectional area of 1M, a high load is not applied to the transformer etc. in which the E-type core is incorporated. Even in such a case, occurrence of magnetic saturation below a predetermined characteristic value at the large thread trimming portion can be prevented.

In addition, since the E-shaped surface of the E-shaped core is processed to be divided into a plurality of parts along the approximate center of the groove provided between the central magnetic leg and the side magnetic leg, cutting work is difficult. In this case, even if the notch position is slightly shifted, there is no fear that an uncut convex portion will remain on the surface of the central magnetic leg, and it is possible to prevent appearance defects from occurring.

Furthermore, by dividing the side magnetic leg portions of the E-shaped core into a plurality of parts, a cutout portion for locking the locking portion of the coil bobbin is formed, so that the coil bobbin can be fitted into the central magnetic leg of the E-type core. The internal stress at the time of cutting can be alleviated by the notch.

Furthermore, by locking the coil bobbin fitted to the central magnetic leg through the notch, the coil bobbin can be temporarily fixed during the process of assembling a transformer or the like.

(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 the E-type core according to the present invention, FIG. 2(a) is a plan view showing the E-type core of the same embodiment, and FIG. 3(a) and 3(b) are perspective views showing the coil bobbin fitted to the E-type core of the same example, and the fourth section is a cross-sectional view showing the XX cross section of the E-type core. A perspective view showing a transformer configured with an E-type core, vgS diagram (a).

(b) is an explanatory diagram explaining another embodiment of the E-type core according to the present invention, and FIGS. 6(a) and (b) are explanatory diagrams explaining other embodiments of the E-type core according to the present invention. , 7 and 8 are perspective views showing a part of the coil bobbin fitted into the E-shaped core according to the present invention.

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 date molded member, both date faces are cut using a disc-shaped grinder or the like made of an abrasive material or the like.

At this time, the cutting process is performed so that both end surfaces of the disc-shaped grinder are hooked onto the side pillars, and at a cutting depth determined by the installation height of the rotating shaft on which the disc-shaped grinder is mounted.

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.

As shown in FIG. 1, the E-type core 51 manufactured by the above method has a groove 56 and a second groove 57 on both sides of the central Mi legs 5 and 2, and the first side magnetic leg 53 and a second side magnetic leg 54 are arranged, and one end of each of the central magnetic leg 52, the first side magnetic leg 53, and the second side magnetic leg 54 is connected by a yoke part 55, and further The central part of the E-type core 51! A cutting groove portion 61 is formed by cutting the l152 and the yoke portion 55.

The E-shaped core 51 has a central magnetic leg cut portion 61a of the cut groove portion 61 formed by the cutting process, and a yoke portion cut portion 6.
1b are on the same plane, and the upper and lower surfaces of the sun-shaped surface of the E-shaped core 51 are cut using the disc-shaped grinder, so that the first side magnetic! l! 153 and the second side magnetic leg 54, a first side magnetic leg notch 63a having a width of W5.
, 63b and second side magnetic leg notches 64a, 64b are formed, respectively.

At this time, there is a relationship Wl<W4 between the width W1 of the central magnetic leg cutting part 61a and the width W4 of the yoke part cutting part 61b, and the left and right parts after subtracting Wl from W4 are the thread cutting parts. Most of them are 60.

In the E-type core 51, as can be seen from FIG. However, W2<
As shown in W3, the yoke portion 55 is wider than the first side magnetic leg 53 and the second side magnetic leg 54.

That is, from the relationship W2<W3, the cross-sectional area of the large thread cutting portion 60 in the yoke portion 55 is within a range that is not smaller than the cross-sectional area of the first side magnetic leg 53 and the second side magnetic leg 54. In addition, the cross-sectional area of the central magnetic leg 52 is the first (
! It is the sum of the cross-sectional areas of the III magnetic leg 53 and the second side magnetic leg 54.

Further, when cutting the central magnetic leg 52 and the yoke portion 55, first side magnetic leg notches 63a having a W5 width at the upper and lower portions of the first side magnetic leg 53 and the second side magnetic leg 54, respectively; 63b
and second side magnetic leg notches 64a and 64b are respectively formed, but due to the relationship W2<W3, the thread cutting large portion 60
In the cutting step, so that the cross-sectional area of
The cutting width and cutting depth of the cutting groove portion 61 are determined.

Further, as shown in FIG. 3(a), a coil bobbin 101 made of a coil etc. wound with enameled wire etc.
A fitting frame 95 is attached to both longitudinal ends of the winding frame 93 through which an insertion hole 94 into which the central magnetic leg 52 of the mold core 51 is inserted is formed, and the fitting frame 95 is supported by a pedestal 96. ing.

At this time, first side magnetic leg notches 63a, 63b and The locking protrusions 103a, 103b and the locking protrusions 104a, 104
b is formed.

Furthermore, an input/output bin 92 is installed in the lower part of the pedestal 96 for transmitting and receiving electrical power to and from the outside.

Therefore, the central magnetic legs 52, the first side magnetic legs 53, and the second side magnetic legs 54 of the pair of E-type cores 51 are fitted into the coil bobbin 101 along the arrows in the same figure. 52 through the insertion hole 94 and the first side magnetic leg notch 63
a, 63b and the second side magnetic leg notches 64a, 64b are the locking protrusions 103a.

103b and locking protrusions 104a and 104b, respectively.

The state in which the coil bobbin 101 configured as described above is assembled into the E-type core 51 can be understood by referring to FIG. The height Hl of the first side magnetic leg 5 is increased by cutting the cutting groove portion 61 on the upper and lower surfaces.
3 and the height H2 of the second side magnetic leg 54.

That is, when the coil bobbin 101 (represented by imaginary lines) made of a coil or the like wound with enameled wire or the like is fitted onto the central magnetic leg 52, both upper and lower winding portions of the coil bobbin are connected to each other. This prevents the first side magnetic leg 53 and the second side magnetic leg 54 from protruding beyond the height H2.

According to the E-type core 51, there is a relationship W, l<W4, and the width of the thread cutting large portion 60 is cut to approximately the center of the first groove 56 and the second groove 57. Even if the notch position is slightly shifted during the cutting process, it is possible to prevent a convex portion that is not cut from remaining on the surface of the central magnetic leg 52.

Further, in the E-shaped core 51, the thread cutting portions 60 are formed on the left and right sides of the yoke portion cutting portion 61b due to the relationship W 1 <W4, but since the E-type core 51 has the relationship W2 < W3, the thread cutting portions 60 are With respect to the cross-sectional area of the first side magnetic leg 53 or the second side m leg 54,
The cross-sectional area of the large thread trimming section 60 can be prevented from becoming small, and magnetic saturation in the large thread trimming section 60 below a predetermined value can be avoided.

Further, the first side magnetic leg 53 and the second (I
The II magnetic leg 54 has first yA magnetic leg notches 63a and 6, respectively.
3b and second side magnetic leg notches 64a, 64b,
Locking protrusions 103h and 103b of the coil bobbin 101
Since the coil bobbin 101 is configured to be locked by the locking protrusions 104a and 104b, the central magnetic leg 52, the 11111111153, and the second side magnetic leg 54 of the E-shaped core 61 are connected to the +ir bobbin 101. Internal stress generated during fitting can be dispersed and relaxed.

Furthermore, the first side magnetic leg notches 63a, 63b and the second
Side magnetic leg notches 64a, 64b and locking protrusions 103a, 1
03b and the locking protrusions 104a and 104b, the coil bobbin 101 can be temporarily fixed to the E-shaped core 51, thereby assisting the process of assembling the transformer and the like.

In addition, as shown in FIG. 3(b), the input/output pin 92
Instead, a coil bobbin 105 with frame leads 98 extending from the side surface of the pedestal 96 may be used.

Next, an example in which a transformer is constructed using one set of the E-type cores 51 described above will be described with reference to FIG. 4.

The E-type core 51 and another E-type core 51 paired with the E-type core 51
The central magnetic leg 52 of the E-type core 5L, the locking projections 103a, 103b, and the locking projection 104a are inserted into the insertion hole 94 of the coil bobbin 101 into which the coil 90 is fitted.

The first side magnetic leg 53 and the second side magnetic leg 54 are respectively fitted or locked to the transformer 104b, and are fixed with a fixing fitting (not shown) or the like, thereby constructing the transformer 100.

Next, another embodiment of the present invention will be described with reference to FIGS. 3(a) and 3(b).

Note 2: The same parts as in the previous embodiment are denoted by the same reference numerals, and the explanation thereof will be omitted.

The first full magnetic leg 53 and the second side magnetic leg 54 are both cut by a disk type grinder or the like having a curved ridge, and a first side magnetic leg notch having a curved shape is formed. 73a
, 73b and the second lateral notch 74a.

74b is formed.

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.
The cutting process is performed while adhering to the rule that the cross-sectional area is the sum of the cross-sectional area of the magnetic head and the second side magnetic leg 54.

As shown in FIG.
A coil bobbin lit is used in which locking protrusions 114a and 114b are formed.

According to the E-shaped core 71, the same excellent effects as in the previous embodiment can be achieved.

Further, another embodiment of the present invention will be described with reference to FIGS. 6(a) and (b).

Note that the same parts as in the previous embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

On the opposing surfaces of the first side magnetic leg 53 and second side ga leg 54 of the E-type core 81, tapered first side magnetic leg notches 83a, 83b and second side magnetic leg are provided, respectively, from the upper surface to the cutting groove grI61. Notches 84a and 84b are formed.

As shown in FIG. 8, the E-shaped core 81 uses a coil bobbin 121 having tapered locking protrusions 123a and 123b.

The E-type core 81 configured as described above provides excellent effects similar to those of the previous embodiment.

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, and then pressure molded. A ferrite core is formed by molding and further configuring.

(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 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 are such that W l < W4
By having the width of the left and right thread notches obtained by subtracting Wt from W4, the upper surface of the central magnetic leg will not be cut even if the notch position is slightly shifted during cutting. There is no fear that the protrusions will remain, and the appearance defects can be prevented, and since the cutting process does not require high machining accuracy, it has the excellent effect of improving the efficiency of one operation.

(2: Also, by having the distance Wi <W4, a large thread cutting portion is formed on the yoke portion, but the first
The radius W2 of the first@magnetic leg or the 21111+1iB leg is set so as to prevent the cross-sectional area of the large thread cutting portion of the yoke portion from becoming smaller than the cross-sectional area of the side magnetic leg or the second side Iiaw. Since the width W3 of the central magnetic leg has the relationship W2 x W3, even if a large load is not applied to the transformer etc. in which the E-shaped core is incorporated, the thread trimming size It has the excellent effect of being able to prevent magnetic saturation below a predetermined characteristic in the transformer, thereby preventing deterioration of the desired characteristics of the transformer or the like.

(3) Further, a first side magnetic leg notch and a second side magnetic leg notch are formed in the first side magnetic leg and the second side magnetic leg of the E-shaped core, respectively, so that the locking protrusion of the coil bobbin The structure is configured to lock the coil bobbin, and the internal stress generated when fitting the central magnetic leg, the first gIIH1 leg, and the second side magnetic leg of the E-shaped core to the coil bobbin is dispersed and alleviated. This has an excellent effect of preventing damage to the E-shaped core when assembling a transformer or the like.

(4) Furthermore, the coil bobbin can be temporarily fixed to the El core 51 by abutting and locking the first side magnetic leg notch and the second side magnetic leg notch with the locking protrusion, respectively.
It has the excellent effect of assisting the assembly process of transformers, etc., and ensuring reliable assembly.

[Brief explanation of 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. 3(a) and 3(b) are perspective views showing a coil bobbin fitted to the E-type core of the same embodiment, and FIG. 4 is a cross-sectional view of the E-type core of the same embodiment. FIGS. 5(a) and (b) are explanatory views illustrating other embodiments of the E-type core according to the present invention; FIGS. 6(a) and (b) are perspective views showing a transformer configured with a type core; FIGS. 9 is an explanatory diagram illustrating another embodiment of the E-type core according to the present invention, FIGS. 7 and 8 are perspective views showing a part of the coil bobbin fitted into the E-type core according to the present invention, and FIG. Figure and 10th
The figure is a perspective view showing a conventional E-type core. Figures 11 (a) to (d) are explanatory diagrams explaining the manufacturing process of a conventional E-type core. Section 12 is a partially cutaway view of the conventional example. FIG. 13 is a sectional view showing a partially cut away cross section of another conventional example; FIG. 14 is a sectional view showing a partially cut away cross section of another conventional example. 56. ...First groove, 57...Second iIII, 60...
Major residual disease portion, 61... Cutting groove portion, 63... First side magnetic leg notch portion 64... Second side magnetic leg notch portion.

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-type core, the width of the yoke portion is made wider than the width of the side magnetic leg, and both E-shaped surfaces of the E-type core are formed into a plurality of parts along the side magnetic leg. E-type core characterized by split processing.