JPH0485908A - E-type core - Google Patents

Abstract

PURPOSE:To prevent a magnetic saturation, to decrease a working accuracy, to improve heat dissipation characteristics and to enable lightening an apparatus by making the width of a yoke part larger than that of a side magnetic leg, by dividing at least one E-type surface into plural parts along the central part of a groove provided between a central magnetic leg and the side magnetic leg and by forming notches in a part opposite to a yoke connection. CONSTITUTION:Both side parts of a central magnetic leg 52 are provided with a first groove 56 and second groove 57, a first side magnetic leg 53 and second side magnetic leg 54 are arranged in the side parts, each one end of the central magnetic leg 52, the first side magnetic leg 53 and second side magnetic leg 54 is connected by a yoke part 55, and a cut groove 61 and other notches 60 are formed in the central magnetic leg 52 and yoke part 55. Further, a fan- shaped central notch 62 is notched in the rear of a connecting position where the yoke part 55 is connected with the central magnetic leg 52. Moreover, the relation between the width W2 of the first side magnetic leg 53 or second side magnetic leg 54 and width W3 of the 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. 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, cores made of magnetic materials used as magnetic cores in transformers, choke coils, noise filters, etc. are required to be thinner and lighter, and various proposals have been made to date. Ta.

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.

An E-type core 1 made of a magnetic material such as ferrite has a first groove 6 and a second groove 7 on both sides of a central magnetic leg 2 having a substantially square cross section, and a pair of first side magnetic legs 3 and a second groove 7. The second side magnetic leg 4 is arranged, and the central magnetic leg 2 and the first side magnetic leg 3
and one end of each of the second side magnetic legs 4 is connected by a yoke portion 5.

At this time, the central magnetic leg 2, the first side magnetic leg 3 and the 2111th magnetic leg
The other end surface of the 11EB leg 4 is formed on the same plane, and in order to optimize the magnetic properties of the E-shaped core I, the cross-sectional area of the central magnetic leg 2 is equal to that of the first side magnetic leg 3 and the first side magnetic leg 3. 2nd side magnetic leg 4
is formed to be equal to the sum of the cross-sectional areas of each.

When incorporating the E-shaped core 1 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 ■-shaped core and fixed with a fixing fitting or the like (not shown).

When the coil bobbin 8 is fitted into the E-type core 1, the upper and lower parts of the winding of the coil bobbin 8 protrude by 7 widths from the upper and lower surfaces of the central magnetic leg 2 of the E-type core 1. It could not be said that the dimensions of each part were effectively utilized in the structural design.

Moreover, when mounting the transformer, etc. on an electronic circuit board, etc., the protruding two-width winding part becomes the mounting part on the board, etc., resulting in problems such as poor stability. .

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 magnetic leg and the second side magnetic leg, E is a core with a structural design that makes effective use of the dimensions of each part. has been devised, and this E-type core will be explained 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 groove 16 and a second groove are formed on both sides of the central magnetic leg 12. A first side magnetic leg 13 and a second side magnetic leg 14 are disposed with a groove 17,
One end of each of the 11th tl magnetic leg 13 and the second side magnetic leg 14 is connected by the yoke portion I5.

Further, in the E-shaped core 11, the other end surfaces of the central magnetic leg 12, 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, the first flll1 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 I2 of the E-type core 11, as shown by the imaginary line in the figure, and when combined with the E-type or I-type core, transformers, etc. is starting 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 first side magnetic leg 13, the second side magnetic leg 14, and the yoke part 15
The height is low compared to the height of the central magnetic leg 12, and therefore there is a space above the central magnetic leg 12, and the upper winding portion of the coil bobbin 18 fitted in the central magnetic leg 12 is leg 13,
It does not protrude beyond the upper surfaces of the second side magnetic leg 14 and the yoke portion 15, and thus the structure is designed to accommodate miniaturization of the E-shaped core 11.

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

According to the above-mentioned double-acting type press device, each pressurizing surface interlocks in a double manner to pressurize the magnetic material, so it is difficult to mold the magnetic material to have a uniform density. There was a risk that microcracks etc. would occur in the E-type core 1 due to internal stress when pressurized.

Furthermore, the double-acting press device (j) 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. 1O (a) to (di) 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 part of the cut piece, the first side magnetic leg 23 and the second side magnetic leg 24 are formed to be snow-resistant on both sides of the central magnetic leg 22, and the central magnetic leg 2
2. 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 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 W4' is the width W of the central magnetic leg cutting part 26a
The yoke portion cutting portion 26 is formed wide with respect to l'.
Generally, all the notches 30 were formed on both sides of b.

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

At this time, by forming the cutting groove portion 26, the height H1 of the central magnetic leg 22 is increased as shown in FIG.
' is the height H of the first side magnetic leg 23 and the second side magnetic leg 24
2, H1' is H2', and therefore the upper winding portion of the coil bobbin is connected to the first side magnetic leg 23 and the second side magnetic leg 23.
This prevents the 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, it is no longer necessary to use the double-acting type press device, and the E-type core 21 can be manufactured using a shooting device and process.

Further, as shown in FIG. 12, the E-type core 31 having a different shape from the E-type core 21 has cutting grooves 37a and 37b on both sides of the central magnetic leg 32, respectively, and a pair of first (I)
The II magnetic leg 33 and the second side magnetic leg 34 are snow-proof, and the central magnetic leg 32. First side magnetic leg 33 and second side magnetic leg 3
4 are connected at one end by a yoke portion 35.

Furthermore, in the E-type core 31, the central magnetic leg 32
The upper surface is cut to a height H1', and the yoke part 35 is cut to a height H3'', which is higher than the height H1', with a tapered part 40 to form a cutting groove part 36. has been done.

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.

(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 '<W4', all the notches are formed in the yoke part, and the width W2' of the first side magnetic leg and the second side magnetic leg and the width W3' of the yoke part are approximately W2' =W
3', 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. If the relationship in which the sum of the areas is equal to the cross-sectional area of the central magnetic leg cannot be maintained, and a high load is applied to a transformer or the like in which the E-type core is incorporated, all the notches will have a predetermined characteristic value. There is a problem in that magnetic saturation occurs in the following, and as a result, desired characteristics of the transformer etc. cannot be obtained.

In addition, in order to avoid magnetic saturation due to all the notches,
The Wl' and W4' have a relationship of approximately Wl'W4',
Even if the central magnetic leg and yoke portion are cut, due to a slight deviation in the notch position during the cutting, a convex portion that is not cut remains on the surface of the central magnetic leg, resulting in poor appearance. Therefore, there is a problem in that the cutting process requires high machining accuracy, and the working efficiency decreases due to the machining accuracy.

In addition, in a transformer or the like constructed by combining the E-type cores, a change in the primary magnetic field is generally caused to act as a change in the secondary magnetic field through mutual induction through the E-type core. A loss occurs during the operation, and the loss generates heat and causes thermal noise, etc. However, no measures have been taken regarding the shape of the E-type core, which may lead to deterioration of the characteristics of the transformer, etc. There was a point.

Furthermore, although the magnetic material constituting the E-type core generally has a high specific gravity, no particular measures have been taken to reduce the weight, and the weight of the transformer etc. in which the E-type core is incorporated is also low. There was a problem with the size.

The present invention has been made in view of the above circumstances, and prevents magnetic saturation below a predetermined characteristic value due to a reduction in the cross-sectional area of the extra notch, and also improves processing accuracy by widening the extra notch. The purpose of the present invention is to provide an E-type core that is relaxed, has improved heat dissipation characteristics, and is lightweight.

(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 part is made wider than the width of the side magnetic leg, and at least one E-shaped surface of the E-shaped core,
A groove provided between the central magnetic leg and the side magnetic legs is divided into a plurality of parts along the center thereof, and a notch is further formed at the opposite part of the yoke connecting part to which the central magnetic leg is connected. By doing so, the above objectives are achieved.

(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 yoke portion is made wider than the width of the side magnetic leg. By protecting the cross-sectional area of the extra notch from becoming small, even if a high load is applied to a transformer, etc. in which the E-type core is incorporated, the extra notch The occurrence of magnetic saturation below a predetermined characteristic value 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 approximate center of the groove provided between the central magnetic leg and the side magnetic legs, cutting Even if the notch position is slightly shifted during machining, there is no risk that a convex portion that is not cut will remain on the central magnetic leg surface, and it is possible to prevent appearance defects from occurring.

In addition, heat loss generated in a transformer or the like constituted by the E-shaped core can be reduced by forming a notch in the opposite part of the connecting part of the yoke part to which the central magnetic leg of the E-shaped core is connected. The cutout portion allows the heat radiation area of the yoke portion to be increased, thereby improving heat radiation efficiency.

Furthermore, since the notch is formed in the yoke portion, the magnetic material with high specific gravity that originally existed in the notch can be removed, thereby making it possible to relatively reduce the weight of the E-shaped core.

(Example) An embodiment of the present invention will be described in detail based on one drawing.

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 explanatory diagrams illustrating other embodiments of the E-shaped core according to the present invention, and FIG. 4(a) is a sectional view showing the XX cross section of the type core.
(b) is an explanatory diagram explaining another embodiment of the E-type core according to the present invention, and FIGS. 5(a) and (b) are explanatory diagrams explaining other embodiments of the E-type core according to the present invention. , FIG. 6 is a perspective view showing a transformer constructed from an E-type core according to the same embodiment, and FIG. 7 is a perspective view showing a state in which the transformer constructed from an E-type core according to the same embodiment is mounted on a board. There is.

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 or the like 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.

Furthermore, since the pressing surface of the sheep-motion type brace 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-type molded member form the same surface. are doing.

Next (2) By cutting the pair of common columns and the central common column of the day molded member at approximately the center, the pair of E-shaped cores are
I# is built.

As shown in FIG. 1, the E-type core 51 manufactured by the above method has a first groove 56 and a second groove on both sides of the central magnetic leg 52. ! 457, the first side magnetic leg 53 and the 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 leg 54 is connected to the yoke part 55. Furthermore, a cutting groove portion 61 is formed in the central magnetic leg 52 and yoke portion 55 of the E-shaped core 51.
is formed by cutting.

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 61.
b are on the same plane, and since the disc type grinder is used which is wider than the central magnetic leg 52, an extra notch 60 is formed in the yoke part 55.

At this time, there is a relationship W1<W4 between the width W1 of the central magnetic leg cutting part 6]a and the width W4 of the yoke part cutting part 61b, and the left and right parts obtained by subtracting Wl from W4 exist. is the extra notch 60.

Further, the yoke portion 55 of the E-shaped core 51 is connected to the central magnetic leg 5.
At the rear part of the connection position connected to 2, a thyroid-shaped central notch 62 is cut out using the fan-shaped grinder or the like.

In the E-type core 51, as can be seen with reference to FIG. 2(a), the relationship between the width W2 of the first side magnetic leg 53 or the second side magnetic leg 54 and the width W3 of the yoke portion 55 is However, W2<W3
As you can see, the yoke portion 55 is connected to the first side magnetic leg 53 and the second side magnetic leg 53.
It is wider than the side magnetic leg 54, and has a relationship of approximately W3=W5 with respect to the width W5 of the central magnetic leg cut portion 61a of the yoke portion 55 cut by the central notch portion 62. There is.

That is, the cross-sectional area of the central magnetic leg 52 is the sum of the cross-sectional areas of the first magnetic leg 53 and the second magnetic leg 54, and similarly, the central magnetic leg 52 has the central notch 62 cut out. Cutting part 61
It is also the sum of the cross-sectional areas of each of a.

Moreover, from the relationship W2<W3, the center notch 6
The cross-sectional area of the yoke portion cutting portion 61b with respect to the first
The central notch 62 is cut out in the yoke portion 55 within a range that is not smaller than the cross-sectional area of the side magnetic leg 53 and the second side magnetic leg 54.

Further, when cutting the central magnetic leg 52 and the yoke part 55, an extra notch 60 is created in the yoke part 55, but due to the relationship W2<W3, the cross-sectional area of the extra notch 60 is In the cutting process, the cutting width and cutting depth of the cutting groove portion 61 are determined so as not to be smaller than the first side magnetic leg 53 and the second side magnetic leg 54.

A CE type core 51 is manufactured as described above.

According to the E-shaped core 51, there is a relationship Wl<W4, and the width of the extra notch 60 is equal to that of the first groove 56 and the second groove.
Since cutting is performed to approximately the center of the groove 57, even if the notch position is slightly shifted during the cutting, it is possible to prevent an uncut convex portion from remaining on the surface of the central magnetic leg 52.

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

Further, heat loss generated in a transformer or the like constituted by the E-shaped core 51 can be avoided if the central notch 62
Since the notch is formed in the connecting rear part of the yoke part 55 where the yoke parts 2 and 2 are connected, the heat dissipation area at the connected rear part of the yaw part becomes large, and therefore the heat radiation efficiency can be improved.

Furthermore, a central notch 62 is provided in the yoke portion of the E-empty core 51.
By forming the notch, the magnetic material with high specific gravity that originally existed in the notch 62 can be removed, thereby making it possible to relatively reduce the weight of the E-empty core.

In the E-air core 51, as shown in FIG. 2(b), the cross-sectional area of the central magnetic leg 52 is equal to
As mentioned above, the height Hl of the central magnetic leg 52 is the sum of the cross-sectional areas of the first side magnetic leg 53 and the second side magnetic leg 53 due to the cut groove 6I being cut. m leg 54
It is formed to have a lower height than the height H2.

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 upper winding portion of the coil bobbin can be prevented from protruding beyond the height H2 of the first side magnetic leg 53 and the second side magnetic leg 111I154.

Note that the center notch 62 is not limited to being formed by molding a die molded member and notching the E-shaped core 51 that has been cut. It may be formed by molding the magnetic material into an 8-shaped molded member.

Further, the cutting groove portion 61 is not limited to being cut and formed only on one side of the E-shaped core 51, but may be cut and formed on both sides.

Next, other embodiments of the present invention will be described with reference to Section 3 (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.

The E-shaped core 71 is formed into an E-shape, and the central magnetic leg 52 and the yoke part 55 are machined, and the rear part of the central magnetic leg 52 of the yoke part 55 has a triangular wedge shape. A central notch 72 is formed.

At this time, the cross-sectional area of the central magnetic leg 52 is equal to that of the first fill
The central notch 72 is formed in the yoke part 55 while adhering to the convention that the cross-sectional area is the sum of the cross-sectional areas of the magnetic leg 53 and the second side magnetic leg 54.

The E-type core 71 configured as described above provides excellent effects similar to those of the previous embodiment.

Further, other embodiments of the present invention are shown in FIGS. 4(a) and 4(a), respectively.
This will be explained with reference to FIG. 5(b) and FIGS. 5(a) and 5(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.

A semicircular center notch 82 is formed at the rear of the yoke connection portion of the E-type core 81, and similarly, the E-type core 9
A rectangular central notch 92 is cut out at the rear of the first yoke connecting portion.

E-type core 81 and E-type core 91 configured as above
Each of these provides excellent effects similar to those of the previous embodiments.

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. 6.

The E-empty core 51 and other E-empty cores paired with the E-empty core 51
The empty cores are mated together, and a coil bobbin 1゜1 consisting of a coil wound with enameled wire or the like is fitted onto the central magnetic leg 52 of the E empty core 5I, and fixed with a fixing fitting etc. (not shown). At this time, the E hollow core 51 is formed with a cutting groove 61 and a central notch 62, and the lead wire 102 of the coil bobbin 101 is connected to the cutting groove 6] and the central notch 62. Notch 62
, and the transformer 100 can be neatly mounted on an electronic circuit board or the like.

Further, FIG. 7 shows the state in which the transformer 100 is mounted on an electronic circuit board, etc., and a frame lead 103 is attached in place of the leader line 102, and is used for transmitting and receiving signals with the outside. .

A cutting groove 61 is formed in the transformer 100, and since the cutting groove 61 provides a mounting space for the frame lead 1.3, by actually installing the frame lead 103 in the space of the cutting groove 61. , the transformer can be surface mounted on an electronic circuit board or the like.

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

The width W1 of the central magnetic leg cut part in the cut groove part of the fIIE type core and the width W4 of the yoke part cut part have a relationship of Wl<W4, and the width of the left and right extra notches is calculated by subtracting Wl from W4. By having this, even if the notch position is slightly shifted during cutting, there is no risk 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 and to prevent the cutting from occurring. Since high machining accuracy is not required for machining, it has the excellent effect of improving work efficiency.

(2) Furthermore, by having the relationship Wl<W4, a large thread cutting portion is formed on the yoke portion, but with respect to the cross-sectional area of the first side magnetic leg or the second side magnetic leg, In order to prevent the cross-sectional area of the large thread cutting portion of the yoke portion from becoming small, the width W2 of the first side magnetic leg or the second side magnetic leg and the width W3 of the central Mi leg are set to be W2 x W3. Therefore, even if a large load is applied to a transformer, etc. in which the E-shaped core is incorporated, magnetic saturation will not occur in the thread cutting section below the predetermined characteristic. Therefore, it has the excellent effect of being able to prevent deterioration of the desired characteristics of the transformer, etc.

(3) Furthermore, the heat loss generated in a transformer etc. composed of the E-shaped core is determined by the rule 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. While following the above, the center cutout is formed in the yoke, so
The heat dissipation area in the yoke portion is large (therefore, the heat dissipation efficiency can be increased, and the performance characteristics of the transformer etc. can be improved, which is an excellent effect.

(4) Furthermore, the yoke part of the E-shaped core has a central notch while following the rule 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. Since the notch is formed, the weight can be reduced by the amount of the notch, and therefore, it has an excellent effect of being able to reduce the weight of a transformer etc. constructed by combining the E-shaped core.

[Brief explanation of the drawing]

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 (b) are explanatory diagrams illustrating other embodiments of the E-type core according to the present invention; FIGS. 4(a) and (b) are cross-sectional views showing the XX cross section of the type core; ) is an explanatory diagram explaining another embodiment of the E-type core according to the present invention, FIGS. 5(a) and 5(b) are explanatory diagrams explaining other embodiments of the E-type core according to the present invention, FIG. 6 is a perspective view showing a transformer configured with an E-type core according to the same embodiment, FIG. 7 is a perspective view showing a state where the transformer configured with an E-type core according to the same example is mounted on a board, and FIGS. Figure 9 is a perspective view showing a conventional E-type core, Figures 10 (a) to (d) are explanatory diagrams explaining the manufacturing process of a conventional E-type core, and Figure 11 is a partially cutaway view of the conventional example. FIG. 12 is a cross-sectional view showing a partially cut away cross-section of another conventional example. 51... E-type core, 52... Central magnetic leg, 5
3... First side magnetic leg, 54... Second side magnetic leg, 55.
・ ・Yoke part, 56 ・ 60 ・ 6l ・ 62 ・ ・First groove, 57 ・Extra notch part, ・Cutting groove part, ・Central notch part.・211th

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. The groove is divided into multiple parts along the center of the groove, and further,
An E-type core characterized in that a notch is formed in a portion opposite to a yoke connecting portion to which the central magnetic leg is connected.