JPH0485909A - E-type core - Google Patents

Abstract

PURPOSE:To prevent a magnetic saturation, to decrease a working accuracy 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, the corners of both ends of the yoke part 55 in the rear of the connecting position of the first side magnetic leg 53 and second side magnetic leg 54 are respectively notched to form first lateral notch 63 and second lateral notch 64 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, 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 7 on both sides of a central magnetic leg 2 having a substantially square cross section, and is connected to a pair of first side magnetic legs 3 and a second groove 7, respectively. A second side magnetic leg 4 is arranged, and one end of each of the central magnetic leg 2, first side magnetic leg 3, and 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 1, 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 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 I-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.

Furthermore, when the transformer or the like is mounted on an electronic circuit board or the like, there are problems such as poor stability because the protruding two-width winding part serves as the mounting part on the board or the like.

For this reason, the E-shaped core has a structural design that effectively utilizes the dimensions of each part 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. has been devised, and this E-type core will be explained with reference to FIG.

In the E-type core 1, a laterally elongated central magnetic leg 12 extends from the lower center of the front surface of the yoke portion 15, and a first groove 16 and a second groove are provided 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 first (1111M1 leg 13 and the 21111FB leg 14) is connected by the yoke portion 15.

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 11111I 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 1, 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-type core II, 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 upper winding part of the coil bobbin 18 fitted in the central magnetic leg 12 is lower than the height of the central magnetic leg 12, and therefore has a space above the central magnetic leg 12.
The a-leg 13, the second side magnetic leg 14, and the yoke portion 15 do not protrude beyond the upper surface thereof, so that a structural design corresponding to miniaturization of the E-shaped core 11 is achieved.

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

According to the above-mentioned double-acting press device, each pressurizing surface works in combination to press 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 apparatus 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. 8(a) to 8(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 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,
An E-shaped core 21 is manufactured in which a yoke portion 25 is formed to connect one end of each of the first (III) magnetic leg 23 and the second side magnetic leg 24.

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
1, and the yoke portion cutting portion 26
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 an L-lance, etc. ing.

At this time, by forming the cutting groove portion 26, as shown in FIG. 9, the height H1' of the central magnetic leg 22 is increased.
However, the first side magnetic leg 23 and the second side &Fiil! 124
Hl <82' with respect to the height H2', so that 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 and to smaller size and lower profile.

According to the above method for manufacturing the E-type core 21, there is no need 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. 10, 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 side magnetic legs. A leg 33 and a second side magnetic leg 34 are arranged, and one end of each of the central magnetic leg 32, the first side magnetic leg 33, and the second side magnetic leg 34 is connected by a yoke part 35. There is.

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 cut 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 on the same plane.

(Problem to be Solved by the Invention) However, according to the above-mentioned conventional E-type core, the width W1' of the central magnetic leg cut part and the width W4' of the yoke part cut part are
By having the relationship '<W4', the entire notch is 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''. =
By having the relationship 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 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,
Even if the central magnetic leg and yoke portion are cut so that Wl' and W4' are approximately in the relationship 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. However, there was a problem in that working efficiency was reduced due to the processing accuracy.

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-mentioned circumstances.The present invention prevents magnetic saturation below a predetermined characteristic value due to the reduction in the cross-sectional area of the extra notch, and also increases the machining accuracy by widening the width of all the notches. The present invention provides an E-type core that is lighter in weight.

(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 legs, and at least one E-shaped surface of the E-shaped core is provided between the central magnetic leg and the side 'fa legs. The above object is achieved by dividing the groove into a plurality of parts along the center and further forming a notch in the opposite part of the yoke connecting part to which the side magnetic legs are connected.

(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 side magnetic leg is By protecting the cross-sectional area of all the notches of the yoke from becoming small,
Even when a high load is applied to a transformer or the like in which the E-type core is incorporated, magnetic saturation can be prevented from occurring below a predetermined characteristic value in all the notches.

Furthermore, since at least one 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, Even if the notch position is slightly shifted during the cutting process, 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.

Furthermore, since a notch is formed in the opposite part of the yoke connecting part to which the side magnetic legs are connected, the magnetic material with high specific gravity that originally existed in the notch can be removed, and the E-type core can reduce the weight of

(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. 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 illustrating another embodiment of the E-type core according to the present invention, and FIG. 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 installation height of the rotary shaft to which the disc-shaped grain 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, 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 first groove 56 and a second groove 57 on both sides of the central magnetic leg 52, and has a first side magnetic leg 53 and a second groove 57. 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 the central magnetic leg 52
A cutting groove portion 61 is formed in the yaw portion 55 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 Wl<W4 between the width W1 of the central magnetic leg cutting part 61a and the width W4 of the second yoke part cutting part 61b, and the left and right parts obtained by subtracting Wl from W4 are An extra notch 60 is formed.

Furthermore, the first side magnetic leg 53 and the second side magnetic leg 54 of the yoke portion 55 are connected to each other at a rear portion thereof, and the yoke portion 55
A first lateral notch 63 and a second lateral notch 64 are formed by notching the corners of both ends.

In the E-type core 51, as can be seen with reference to FIG. 2(8), 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 are The relationship is W2<W
3, the yoke portion 55 is wider than the first side magnetic leg 53 and the second side magnetic leg 54.

At this time, 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
The first and second lateral notches 63 and 63 on the left and right sides of the yoke portion 55
It is also the sum of the cross-sectional areas of the side notches 64.

That is, the first lateral notch 63 and the second lateral notch 64
The cross-sectional area of both sides of the yoke portion 55 is within a range that is not smaller than the cross-sectional area of the 11111ifi leg 53 and the second side magnetic leg 54, respectively. Two side notches 64 are cut out.

Further, when cutting the central Mi 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.

The E-type core 51 configured as described above is manufactured.

According to the E-shaped core 51, there is a relationship Wl<W4, and the width of the extra notch 60 is equal to the width of the first full 56 and the second full notch 56.
Since cutting is performed to approximately the center of the magnetic leg 57, even if the notch position is slightly shifted during the cutting, it is possible to prevent a convex portion that is not cut from remaining on the surface of the central magnetic leg 52.

In addition, in the E-shaped core 51, extra notches 60 are formed on the left and right sides of the yoke cutting portion 61b due to the relationship Wl<W4, but since the relationship W2<W3 exists, the first side The cross-sectional area of the extra notch 60 can be prevented from becoming smaller than the cross-sectional area of the magnetic leg 53 or the second side magnetic leg 54, and magnetic saturation at a predetermined value or less in the extra notch 60 can be prevented. can be avoided.

Furthermore, since the first lateral notch 63 and the second lateral notch 64 are formed in the yoke portion of the E-shaped core 51, the first lateral notch 63 and the second lateral notch 64 are originally cut out. The magnetic material present in the portion 64 can be removed, and the weight of the E-shaped core 51 can therefore be reduced.

In the E-shaped core 51, as shown in FIG. 2(b), the cross-sectional area of the central magnetic leg 52 is the first side ia! l! I] 53 and the cross-sectional area of the second side magnetic leg 54, and the cutting groove portion 61 is formed by cutting, so that the central magnetic leg 52
The height Hl is lower than the height H2 of the first side magnetic leg 53 and the second side magnetic leg 54.

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 54.

Note that the first lateral notch 63 and the second lateral notch 64
are not limited to being formed by notching the E-shaped core 51 that has been molded into a day-shaped molded member and cut.
It may be formed by molding the magnetic material into a molded member using a mold having the following.

Moreover, the first side notch 63 and the second side notch 64
Either one may be formed.

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, another embodiment of the present invention will be described with reference to FIGS. 3(a) and 3(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. but,
A first lateral notch 73 and a second lateral notch 74 each having a curved shape are 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.
And the second side magnetic ll! 154, the first lateral notch 73 and the second lateral notch 74 are cut out in the yoke part 55.

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 (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.

Behind the connecting portions of the first side magnetic leg 53 and the second side magnetic leg 54 of the E-shaped core 81, there is a square-shaped first side notch 83, respectively.
A second lateral notch 84 is formed as a cutout.

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

Next, referring to FIG. 5, a description will be given of how a transformer is constructed using one set of the E-type cores 51 described above and is further mounted on a board.

The E-type core 51 and another E-type core 51 paired with the E-type core 51
When the type cores are combined, a coil bobbin IO1 consisting of a coil or the like wound with enameled wire or the like is fitted into the central magnetic leg 52 of the E-type core 51, and is fixed with a fixing fitting or the like (not shown). , a transformer 100 is formed. Further, a cut groove portion 61 is formed in the transformer 100, and the cut groove portion 61 provides a mounting space in which a frame lead 1.03 for transmitting and receiving signals with the outside is attached. Therefore, by actually attaching the frame lead 103 in the space of the cut groove portion 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 powder is used, a binder is added to the ferrite powder and granulated. 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 that goes into the cut groove of the E-type core and the width W4 of the cut part of the yoke part have a relationship of Wl<W4, and further subtract W from W4. By having the extra notch width on the left and right sides, even if the notch position is slightly shifted during cutting, there is no risk of a convex part remaining on the top surface of the central magnetic leg that is not machined (no appearance defects may occur). This method has an excellent effect of improving work efficiency since the cutting process does not require high machining accuracy.

(2) Also, by having the relationship Wl<W4, an extra notch is formed on the yoke part, but the width W2 of the first side magnetic leg or the second (RllFil leg) and the width of the central magnetic leg are Since the radius W3 has the relationship W2<W3,
It is possible to prevent the cross-sectional area of the extra notch of the yoke portion from becoming smaller than the cross-sectional area of the first (111Mi leg or the second side magnetic leg), and the transformer etc. in which the E-type core is incorporated can be prevented. Even when a large load is applied to the transformer, it is possible to prevent magnetic saturation below a predetermined characteristic in the extra notch, thereby preventing loss of desired characteristics of the transformer, etc. It has the excellent effect of being able to

(3) Furthermore, in the yoke part of the E-shaped core, a first side Since the cutout portion and the second side cutout portion are cut out, the weight can be reduced by the amount of the cutout, and therefore the weight of the transformer etc. formed by combining the E-shaped core can be reduced. We praise the excellent effect of being able to do this.

[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 illustrating another embodiment of the E-type core according to the present invention, FIG. Figure 7 is a perspective view showing a conventional E-type core, Figures 8 (a) to (d) are explanatory diagrams explaining the manufacturing process of a conventional E-type core, and Section 9 is a partially cutaway view of the conventional example. FIG. 1O is a cross-sectional view showing a partially cut away cross-section of another conventional example. 51...E-type core, 52...Central magnetic leg, 53
---First side Faob, 54=-Second side magnetic leg, 55・
・ ・Yoke part, 56... ・First groove, 57... Second groove, 60... Full notch part, 61... Cutting groove part, first side cut arrow part, 64... Second side Hokiri Obe.

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 the yoke connecting portion to which the side magnetic legs are connected.