JPH0795489B2 - E type core - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an E-shaped core made of a magnetic material used for a magnetic core such as a transformer, a choke coil, and a noise filter. The present invention relates to an E-shaped core whose structure is effectively utilized.

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

For this reason, transformers, choke coils, noise filters and the like used in these electronic devices are also desired to be small and lightweight.

Therefore, even for a core made of a magnetic material used as a magnetic core of the transformer, choke coil, noise filter, etc., there is a strong demand for thinning and weight reduction, and various proposals have been made so far. .

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

An E-shaped core 1 made of a magnetic material such as ferrite has a pair of first side magnetic legs 3 each having a first groove 6 and a second groove 7 on both left and right sides of a central magnetic leg 2 having a substantially square cross section. And the second
The side magnetic legs 4 are arranged so as to face each other so as to be sandwiched therebetween, and one end of each of the central magnetic leg 2, the first side magnetic leg 3 and the second side magnetic leg 4 is connected by a yoke portion 5. .

At this time, the other end surfaces of the central magnetic leg 2, the first magnetic leg 3 and the second magnetic leg 4 are formed on the same plane, and
In order to optimize the magnetic characteristics of the die core 1, the central magnetic leg 2
Is formed to be equal to the sum of the cross-sectional areas of the first magnetic leg 3 and the second magnetic leg 4.

When the E-shaped core 1 is assembled in a transformer or the like, a coil bobbin 8 made of a coil around which an enamel wire or the like is wound is fitted to the central magnetic leg 2 as shown by a phantom line in FIG. Further, it is fixed in combination with an E-type or I-type core by a fixing fitting or the like not shown.

When the coil bobbin 8 is fitted to the E-shaped core 1, the upper and lower windings of the coil bobbin 8 are projected in the Z width from the upper and lower surfaces of the central magnetic leg 2 of the E-shaped core 1, and thus the E-shaped core 1 It cannot be said that the dimensions of each part are effectively utilized in the construction design of.

Moreover, when the transformer or the like is mounted on an electronic circuit board or the like, there is a problem that the protruding Z-width winding portion serves as a mounting portion on the board or the like and thus is not stable.

Therefore, while satisfying the condition that the cross-sectional area of the central magnetic leg is equal to the sum of the cross-sectional areas of the first-side magnetic leg and the second-side magnetic leg, the E-shaped core is designed to make effective use of the dimensions of each part. Has been devised, and this E-type core will be described with reference to FIG.

The E-shaped core 11 has a laterally elongated central magnetic leg 12 extending from a substantially lower front center of a yoke portion 15 and a first groove 16 so as to sandwich the left and right sides of the central magnetic leg 12. And second groove 17
The first side magnetic leg 13 and the second side magnetic leg 14 are arranged opposite to each other, and one ends of the first side magnetic leg 13 and the second side magnetic leg 14 are connected by the yoke portion 15.

Further, the E-shaped core 11 includes the central magnetic leg 12 and the first side magnetic leg 13
And the other end surface of the second magnetic leg 14 is formed on the same surface, and the lower surfaces of the central magnetic leg 12, the first magnetic leg 13 and the second magnetic leg 14 are formed on the same surface. It is composed by.

A coil bobbin 18 is fitted to the central magnetic leg 12 of the E-shaped core 11 as shown by an imaginary line in the figure, and further combined with an E-shaped or I-shaped core to form a transformer or the like. It has become so.

According to the E-shaped core 11, since the central magnetic leg 12 is elongated in the lateral direction, the height of the central magnetic leg 12 is increased by the first magnetic leg 13, the second magnetic leg 14, and The height of the yoke portion 15 is lower than that of the yoke portion 15, so that there is a space above the central magnetic leg 12 and the coil bobbin fitted to the central magnetic leg 12 is provided.
The upper winding portion of 18 does not project above the upper surfaces of the first side magnetic leg 13, the second side magnetic leg 14, and the yoke portion 15, and therefore, the structural design corresponding to the downsizing of the E-shaped core 11 is achieved. Has been done.

The E-shaped core 11 is molded by pressing a magnetic material with a double-acting press machine (not shown) having a plurality of pressing surfaces, for example.

According to the above-mentioned double-acting type press machine, since each pressurizing surface interlocks in multiple ways to press the magnetic material, it is difficult to mold the magnetic material so as to have a uniform density. When the double-acting pressure is applied, internal stress may cause micro cracks or the like in the E-shaped core 11.

Further, the double-action press machine is large in size, complicated in operation control, and slow in molding speed, so that it is not suitable for mass production.

Therefore, a method of manufacturing an E-shaped core as shown in FIGS. 11 (a) to 11 (d) has been proposed.

According to this method, a magnetic material is molded into a molding member 28 by a single-acting press device (not shown) (FIG. 10A), and the molding member 28 is cut into cutting grooves 27a and 27b by a lathe or the like. ((B) in the figure).

Next, the molding member 28 is sequentially cut into a predetermined width (FIG. 7C), and the substantially central upper portion of the cut piece is cut to form the first magnetic leg on both left and right sides of the central magnetic leg 22. 23 and second
The side magnetic legs 24 are formed to face each other, and the central magnetic legs 2
2. E-shaped core having an E-shaped planar shape in which a yoke portion 25 that connects one end of each of the first side magnetic leg 23 and the second side magnetic leg 24 is formed
21 are manufactured.

The E-shaped core 21 has an upper surface (referred to as a central magnetic leg cutting portion 26a) formed by cutting the upper portion of the central magnetic leg 22 by the cutting processing and a width W4 'of the upper portion of the yoke portion 25 by the cutting processing.
The upper surface (referred to as the cutting portion 26b of the yoke portion) formed by cutting over the entire surface is flush with the upper surface of the first and second magnetic legs 23 and 24 (referred to as the cutting groove portion 26). And the width W4 ′ of the yoke cutting portion 26b of the cutting groove portion 26 is formed.
Is formed wider than the width W1 'of the central magnetic leg cutting portion 26a, and the width W1 of the central magnetic leg 22 is formed on both sides of the yoke portion cutting portion 26b.
Generally, a cutting surface (referred to as a notch 30) protruding from 1'is formed.

In the E-shaped core 21, a coil bobbin (not shown) has a central magnetic leg 22.
It is fitted to the core and is combined with another E-type or I-type core to form a transformer or the like.

At this time, since the cutting groove portion 26 is formed,
As shown in FIG. 12, the height H1 ′ of the central magnetic leg 22 is greater than the height H2 ′ of the first side magnetic leg 23 and the second side magnetic leg 24.
Since H1 ′ <H2 ′, the upper winding portion of the coil bobbin is prevented from protruding from the upper surfaces of the first side magnetic leg 23 and the second side magnetic leg 24, and is stable to an electronic circuit board or the like. It contributed to mounting and miniaturization.

According to the method for manufacturing the E-shaped core, it is not necessary to use the double-acting press machine, and the E-shaped core 21 can be manufactured by a general apparatus and process.

Further, in Japanese Utility Model Laid-Open No. 2-8117, as shown in the sectional view of FIG. 13, a pair of first side magnetic legs 33 and a second magnetic leg 33 and a second magnetic leg 33 having cutting grooves 37a and 37b on both sides of the central magnetic leg 32 are provided. The side magnetic legs 34 are arranged to face each other, and the central magnetic legs 32, the first side magnetic legs 33 and the second magnetic legs 33
Disclosed is an E-shaped core 31 having a shape different from that of the E-shaped core 21 configured by connecting one end of each of the side magnetic legs 34 with a yoke portion 35.

In the E-shaped core 31, the upper surface of the central magnetic leg 32 has a height H
While being cut to 1 ', the yoke 35 is
A cutting surface (referred to as a cutting groove portion 36) having a tapered portion 40 on the left and right sides and formed by cutting is formed at a height H3 'which is taller than 1'.

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.

(Problems to be Solved by the Invention) However, according to the conventional E-shaped cores 1, 11, 21, and 31 described above, when the coil bobbin is fitted to the central magnetic leg to assemble a transformer or the like, in the assembling process, There is a problem that the connecting portion may be damaged due to the concentration of internal stress in the connecting portion between the central magnetic leg and the yoke portion.

Further, the coil bobbin generally has a line-symmetrical shape, and in the assembly process of fitting the coil bobbin to the central magnetic leg of the E-shaped core to assemble a transformer or the like, the coil bobbin is sufficiently tentatively attached to the E-shaped core. Even after the fitting, the central magnetic legs are not fixed and internal stress concentrates and breaks, and rattling of the side magnetic legs causes a problem in assembly.

The present invention has been made in view of the above circumstances, and the coil bobbin can be reliably assembled by being locked to the E-shaped core without fear of damaging the connecting portion such as the central magnetic leg during the assembly process of the transformer and the like. It provides an E-shaped core.

(Means for Solving the Problem) The present invention is directed to a central magnetic leg and a pair of first and second sides which are arranged to face each other so as to sandwich the central magnetic leg from the left and right with first and second grooves respectively. The yoke portion of the E-shaped core having an E-shaped planar shape, which has a magnetic leg and a yoke portion that connects one end of the central magnetic leg and one end of each of the pair of first and second magnetic legs to each other. Is wider than the widths of the first and second magnetic legs, and at least one of the central magnetic legs on the E-shaped surface and a part of the yoke portion is connected to the central magnetic legs and the first and second magnetic legs. First along the first and second grooves provided between the side magnetic leg and
E machined to be lower than the height of the second magnetic leg
In the mold core, the central magnetic leg and a part of the yoke portion are cut and formed at the same time on each side surface of the first and second magnetic legs on the central magnetic leg side along the magnetic leg length direction. The cutting bottom surface has a first side magnetic leg cutout portion and a second side magnetic leg cutout portion having a tapered or curved shape, and the upper surface of the cut yoke portion is flush with the upper surface of the central magnetic leg and at the center. The yoke portion cutting portion having the same width as the magnetic leg and the excess cutout portion reaching the middle of the width of the first and second grooves, and the first and second sides which are tapered or curved from the end of the excess cutout portion. The object described above is achieved by providing an E-shaped core comprising: a yoke portion, which is continuous with the magnetic leg notch portion, and a yoke portion inclined notch portion on both left and right sides which are cut.

(Operation) In the present invention, when the central magnetic leg and a part of the yoke portion are cut along the magnetic leg length direction on each side surface of the first and second magnetic legs of the E-shaped core on the side of the central magnetic leg. Since the cutting bottom formed by cutting at the same time has the first magnetic leg notch and the second magnetic leg notch which are tapered or curved, fitting of the coil bobbin fitted to the central magnetic leg is performed. An engaging portion provided on a frame (also referred to as a collar portion) can be engaged with the first side magnetic leg cutout portion and the second side magnetic leg cutout portion, whereby the coil bobbin is used in an assembly process of a transformer or the like. Can be temporarily fixed.

Therefore, the internal stress when fitting the coil bobbin to the central magnetic leg of the E-shaped core is dispersed to the first and second side magnetic leg notches, and the internal stress is applied to the connecting portion between the central magnetic leg and the yoke portion. You can ease your focus.

Further, since the E-shaped core and the coil bobbin are temporarily fixed without rattling by the engagement between the first and second magnetic leg notch portions and the engagement portion provided on the fitting frame of the coil bobbin, the later assembly It will not hinder the process.

Further, the inclined sloped notch portion of the yoke portion, which is formed by cutting the yoke portion and is continuous with the notch portion of the first and second magnetic legs, complements the yoke portion by cutting, and thus the connecting strength of the first and second magnetic legs. It is hard to damage.

(Example) The Example of this invention is described in detail based on drawing.

FIG. 1 is a perspective view showing an embodiment of an E-shaped core according to the present invention, and FIG. 2 (a) is a plan view showing the E-shaped core of the same embodiment.
2 (b) is a sectional view showing an E-shaped core XX section of the same embodiment, and FIGS. 3 (a) and 3 (b) are perspective views showing a coil bobbin fitted to the E-shaped core of the same embodiment. 4 and 5 are perspective views showing a transformer constructed by the E-type core of the same embodiment, and FIGS. 5 (a) and 5 (b) are explanations for explaining another embodiment of the E-type core according to the present invention. FIGS. 6 (a) and 6 (b) are explanatory views for explaining another embodiment of the E-shaped core according to the present invention, and FIG.
FIG. 8 and FIG. 8 are perspective views showing a part of the coil bobbin fitted to the E-shaped core according to the present invention.

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

A pair of side pillars (which will be the yoke portion described below) of magnetic material and a pair of common pillars (first and second side magnetic legs described below) that connect both end portions of the side pillars by a single-acting press device or the like. And)
A day-molding member having a central common pillar (which will be a central magnetic leg described later) connecting the central portions of the pair of side pillars is formed and processed.

The surfaces of the pair of side pillars and the central common pillar are cut along the central common pillar of the day-shaped molding member by a disc grinder or the like formed of an abrasive or the like.

At this time, in the cutting process, a disc grinder having a ridge (cutting edge surface) having a tapered or curved shape is used, and a part of the ridge of the disc grinder hangs on the pair of common columns. Thus, the diameter of the lowest point of the ridge (that is, the diameter of the bottom surface of the grinder) is set smaller than the distance between the pair of common columns and larger than the center common column width.

When the disk type grinder is horizontally supported by a rotation shaft at a predetermined height and horizontally rotated while being horizontally moved in the direction of the central common pillar, the ridges of the grinder cause a taper shape to the central common pillar side of the pair of common pillars. A curved cutting surface is formed,
The side pillar has a cutting surface that is coplanar with the cutting surface of the central common pillar, a cutout portion that reaches the middle of the width of the groove between the common pillar and the central common pillar that are also coplanar, and the cutout portion. An inclined cutting surface that is tapered or curved from the end of the portion and is continuous with the inclined cutting surface of the common column is formed.

It is premised that the thickness of the disc grinder is equal to or greater than the cutting depth, and a predetermined cutting depth is set by adjusting the cutting depth according to the installation height of the rotary shaft attached to the shaft.

In addition, since the press surface of the single-acting type press machine is processed into a flat surface, the upper surface and the lower surface of the pair of side columns, the pair of common columns, and the center common column of the date forming member have the same surface. is doing.

Next, a pair of E-shaped cores are manufactured by cutting the pair of common pillars and the center common pillar of the day molding member at approximately the center.

As shown in FIG. 1, the E-shaped core 51 manufactured by the above method has the first groove 56 and the second groove 57 on both sides of the central magnetic leg 52.
And a pair of first side magnetic leg 53 and second side magnetic leg 54 are arranged so as to face each other so as to be sandwiched from the left and right, and the central magnetic leg 52, the first side magnetic leg 53 and the second side magnetic leg 54 Each one end is connected by a yoke portion 55 to form an E shape,
In addition, by the cutting process, the first side magnetic leg notch 63 and the second magnetic leg notch 63 having a tapered bottom surface are formed on the side surfaces of the first and second side magnetic legs 53, 54 on the side of the central magnetic leg along the magnetic leg length direction. Side magnetic leg notches 64 are formed.

Further, by the above-mentioned cutting work, a space is formed at the same time on the central magnetic leg 52 of the E-shaped core 51 and the upper portion of the yoke portion 55, and the central magnetic pole is lower than the first and second side magnetic legs 53, 54. An upper surface of the leg 52 (referred to as the central magnetic leg cutting portion 61a) and an upper surface portion (referred to as the yoke portion cutting portion 61b) having the same width as the width W1 of the central magnetic leg 52 in the yoke portion 55 are formed (the central portion thereof). The magnetic leg cutting portion 61a and the yoke portion cutting portion 61b are on the same surface, and are collectively referred to as a cutting groove portion 61).

Further, the yoke portion 55 has a cutout portion 61 which forms a continuous plane with the excess cutout portion 60 which reaches the middle of the width of the first and second grooves 56 and 57.
Then, a yoke inclined cutout portion 65 having a horizontal width W5 which is tapered from the end of the excess cutout portion 60 and is continuous with the first and second side magnetic leg cutout portions 63 and 64 is formed.

At this time, the width W1 of the central magnetic leg cutting portion 61a and the yoke portion 55
There is a relation of W1 <W4 between the yoke cut portion 61b and the width W4 including the extra cutout portion 60, and W4 <(spacing between the first and second side magnetic legs 53 and 54) <W4 + 2 × W5 relationship.

As can be seen from FIG. 2A, the E-shaped core 51 having the above-described configuration has the width of the upper surface of the first magnetic leg 53 or the second magnetic leg 54.
The yoke portion 55 is wider than the first magnetic leg 53 and the second magnetic leg 54 so that the relationship between W2 and the width W3 of the yoke portion 55 is W2 <W3.

That is, from the relationship of W2 <W3, the cross-sectional area of the excess cutout portion 60 in the yoke portion 55 is determined by the first magnetic leg 53 and the second magnetic leg.
While following the range that is not smaller than the cross-sectional area of 54, the cross-sectional area of the central magnetic leg 52 is such that the first magnetic leg 53 and the second magnetic leg 54
It is the sum of the cross-sectional areas of.

Further, when the central magnetic leg 52 and the yoke portion 55 are cut, the first side magnetic leg cutout 63 and the second side magnetic leg having the width W5 in the first side magnetic leg 53 and the second side magnetic leg 54 are formed. The leg notches 64 are formed respectively, but because of the relationship of W2 <W3, the cross-sectional area of the extra notches 60 is not smaller than that of the first magnetic leg 53 and the second magnetic leg 54. In the cutting step, the cutting groove 61
The cutting width and cutting depth of are determined.

Further, as shown in FIG. 3 (a), a coil bobbin 101 including a coil wound with an enameled wire or the like is formed with an insertion hole 94 through which the central magnetic leg 52 of the E-shaped core 51 is inserted. Fitting frames 95 are attached to both ends of the winding frame 93 in the longitudinal direction, and the fitting frames 95 are supported by a pedestal 96.

At this time, the E-shaped core 51 is provided on both upper and left sides of the fitting frame 95.
Of the first magnetic leg 53 and the second magnetic leg 54 of the
Locking protrusions 103a and 103b are formed so that the side magnetic leg notch 63 and the second side magnetic leg notch 64 are contacted and temporarily fixed.

Further, on the pedestal 96, an input / output pin 92 for transmitting / receiving an electric signal to / from the outside is planted in a lower portion.

Therefore, the center magnetic leg of the pair of E-shaped cores 51 is
52, the first magnetic leg 53 and the second magnetic leg 54 are fitted to the coil bobbin 101, whereby the central magnetic leg 52 is inserted into the insertion hole 9
4, the first side magnetic leg cutout 63 of the first side magnetic leg 53 and the second side magnetic leg cutout 64 of the second side magnetic leg 54 are locked by the locking projections 103a,
It is fixed and locked by 103b.

The state in which the coil bobbin 101 is incorporated in the E-shaped core 51 as described above can be understood by referring to FIG. 2 (b), and the height H1 of the central magnetic leg 52 can be understood.
However, since the cutting groove portion 61 is formed by cutting,
The height is set to be lower than the height H2 of the first magnetic leg 53 and the second magnetic leg 54.

That is, the coil bobbin 101 (indicated by phantom lines), which is composed of a coil around which an enamel wire or the like is wound, is
It is prevented that one upper winding portion of the coil bobbin, when fitted to the above, protrudes from the height H2 of the first side magnetic leg 53 and the second side magnetic leg 54.

Further, in the E-shaped core 51, due to the relationship of W1 <W4, the extra cutouts 60 are formed on the left and right of the yoke cutting portion 61b, but W2 <W3
Therefore, it is possible to prevent the cross-sectional area of the extra cutout 60 from becoming smaller than the cross-sectional area of the first side magnetic leg 53 or the second side magnetic leg 54. , The extra notch
Magnetic saturation below a predetermined value at 60 is avoided.

Further, the first side magnetic leg 53 and the second side magnetic leg 54 of the E-shaped core 51.
First side magnetic leg notch 63 and second side magnetic leg notch 64, respectively.
To form the locking protrusions 103a, 103 of the coil bobbin 101.
Since the coil bobbin 101 is configured to be locked by b, when the central magnetic leg 52, the first magnetic leg 53 and the second magnetic leg 54 of the E-shaped core 51 are fitted to the coil bobbin 101. It is possible to disperse and relax the internal stress generated in the.

Incidentally, the yoke inclined notch portion 65 of the yoke portion consequently exerts an effect of increasing the connection strength between the first and second magnetic legs 53, 54 and the yoke portion 55.

Further, the first side magnetic leg notch 63 and the second side magnetic leg notch
The coil bobbin 101 can be temporarily fixed to the E-shaped core 51 by abutting and locking the 64 and the locking projections 103a and 103b, respectively, so that the fitted E-shaped core 51 does not rattle, and It can assist the assembly process of transformers and the like.

As shown in FIG. 3B, a coil bobbin 105 having a frame lead 98 extending from the side surface of the pedestal 96 may be used instead of the input / output pin 92.

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

The E-shaped core 51 and another E-shaped core forming a pair with the E-shaped core 51 are combined, and a central magnetic leg 52 of the E-shaped core 51 is combined.
In the insertion hole 94 of the coil bobbin 101, and the first magnetic leg 5
The transformer 100 is configured by fitting and locking the third magnetic leg 54 and the second magnetic leg 54 on the locking protrusions 103a and 103b, respectively, and fixing them by fixing fittings or the like not shown.

Next, another embodiment of the present invention will be described with reference to FIGS. 5 (a) and 5 (b).

The same parts as those in the previous embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the figure, a first side magnetic leg notch 73 having a curved bottom surface along the magnetic leg length direction is formed on each side of the first and second side magnetic legs 53, 54 of the E-shaped core 71 on the side of the central magnetic leg. The second side magnetic leg cutout portion 74 is formed.

In addition, the central magnetic leg 52 of the E-shaped core 71 is simultaneously cut by cutting.
Also, a central magnetic leg 52 having a lower space than the first and second magnetic legs 53, 54 by having a space for cutting above the yoke portion 55.
Upper surface (referred to as the central magnetic leg cutting portion 61a) and the yoke portion 55
An upper surface portion (referred to as a yoke cutting portion 61b) having the same width as the width W1 of the central magnetic leg 52 in is formed (the central magnetic leg cutting portion 61a and the yoke portion cutting portion 61b are flush with each other. , Together with the cutting groove 61).

Further, the yoke portion 55 forms a continuous plane with the cutting groove portion 61, and an excess cutout portion 60 halfway to the width of the first and second grooves 56 and 57.
Then, a curved curved yoke portion cutout portion 75 is formed from the end of the excess cutout portion 60 and is continuous with the first and second magnetic leg cutout portions 73 and 74.

At the time of this cutting process, in accordance with the rule that the cross-sectional area 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 54, as in the above embodiment. Needless to say

Further, chamfered portions 76 and 77 are formed on outer lower portions of the first side magnetic leg 53 and the second side magnetic leg 54.

As shown in FIG. 7, the E-shaped core 71 configured as described above is provided with a curved portion matching the curved surface shape of the first side magnetic leg cutout portion 73 and the second side magnetic leg cutout portion 74. Locking projection 113a having
The coil bobbin 111 in which 113b is formed is used.

According to the E-shaped core 71, the engaging protrusions 113a and 113b of the coil bobbin 111 engage with the first side magnetic leg cutout portion 73 and the second side magnetic leg cutout portion 74 and are temporarily fixed. It has the same excellent effect as the example.

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

The same parts as those in the previous embodiment are designated by the same reference numerals and the description thereof will be omitted.

Central magnetic leg of first side magnetic leg 53 and second side magnetic leg 54 of E-shaped core 81
The first side magnetic leg notch 83 and the second side magnetic leg notch 84 which are tapered from the upper surface to the extra notch 60 are provided on the opposite side surface on the 52 side.
55 and the tapered yoke inclined cutout portion 85 which is integrally continuous with the upper surface of the yoke in FIG. 55 is formed as a surplus cutout portion 60 until it reaches the middle of the width of the first and second grooves 56, 57. It is formed adjacently.

As shown in FIG. 8, the E-shaped core 81 is provided with locking projections 123a and 123b which are tapered in accordance with the tapered first magnetic leg notch 83 and second magnetic leg notch 84, respectively. The coil bobbin 121 having is used.

Also in the E-shaped core 81 configured as described above, the E-shaped core
It is needless to say that the 81 and the coil bobbin 121 are locked and temporarily fixed, and the same excellent effects as those of the previous embodiment are achieved.

In addition, as a reminder, as will be apparent from the above three embodiments, the first side magnetic leg cutout portion, the second side magnetic leg cutout portion, and the yoke portion of the yoke portion, the inclined cutout portion is the central magnetic leg or the yoke portion. It can be formed at the same time as the cutting groove portion is formed by cutting, and no additional extra cutting step is required.

When iron powder is applied to the magnetic material, a dust core is formed by pressure molding, and when ferrite powder is applied, a binder is added to the ferrite powder to granulate and add. 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 effects described below.

(1) The first side magnetic leg and the second side magnetic leg of the E-shaped core are formed with a first side magnetic leg cutout portion, a second side magnetic leg cutout portion and a yoke portion inclined cutout portion, respectively, to form a coil bobbin. Of the central magnetic leg, the first magnetic leg and the second magnetic leg of the E-shaped core, which are configured to lock the coil bobbin by the locking protrusion of Therefore, it has an excellent effect that damage to the E-shaped core can be prevented when the transformer or the like is assembled.

(2) Further, the first side magnetic leg cutout portion and the second side magnetic leg cutout portion are respectively brought into abutment with the locking projections provided on the fitting portion of the coil bobbin, whereby the coil bobbin is E-shaped. Since it can be temporarily fixed to the core 51, it has an excellent effect that the assembly process of the transformer and the like after fitting can be assisted, and reliable assembly can be performed.

[Brief description of drawings]

1 is a perspective view showing an embodiment of the E-shaped core according to the present invention, FIG. 2 (a) is a plan view showing the E-shaped core of the same embodiment, and FIG. 2 (b) is an E of the same embodiment. Sectional drawing which shows the XX cross section of a type | mold core, FIG.3 (a), (b) is a perspective view which shows the coil bobbin fitted in the E type | mold core of the same Example, and FIG. 4 is E of the same Example. 5A and 5B are perspective views showing a transformer constituted by a mold core, FIGS. 5A and 5B are explanatory views for explaining another embodiment of the E-shaped core according to the present invention, and FIGS. 6A and 6B. ) Is an explanatory view for explaining another embodiment of the E-shaped core according to the present invention, and FIGS. 7 and 8 are perspective views showing a part of the coil bobbin fitted to the E-shaped core according to the present invention, 9 and 10 are perspective views showing a conventional E-shaped core, FIGS. 11 (a) and 11 (b) are explanatory views for explaining the manufacturing process of the conventional E-shaped core, and FIG. part FIG. 13 is a cross-sectional view showing a cut-away cross section, and FIG. 13 is a cross-sectional view showing a cut-away cross section of another conventional example. 51 …… E-shaped core, 52 …… Central magnetic leg, 53 …… First side magnetic leg, 54 …… Second side magnetic leg, 55 …… Yoke part, 56 …… First groove, 57 …… Second Groove, 60 …… Excessive cutout portion, 61 …… Cutting groove portion, 61a …… Central magnetic leg cutting portion, 61b …… Yoke portion cutting portion 63 …… First side magnetic leg notch portion, 64 …… Second side magnetic leg Notch, 65 ... Sloping notch on the yoke.

Claims (1)

[Claims] 1. A central magnetic leg, a pair of first and second side magnetic legs arranged to face each other so as to sandwich the central magnetic leg from the left and right with first and second grooves respectively, and the central magnetic leg. The width of the yoke portion of the E-shaped core having an E-shaped planar shape having one end and one of the pair of first and second side magnetic legs connected to each other. The magnetic leg is made wider than the side magnetic leg, and at least one central magnetic leg on the E-shaped surface and a part of the yoke portion are provided between the central magnetic leg and the first and second side magnetic legs. Along the formed first and second grooves,
E machined to be lower than the height of the second magnetic leg
In the mold core, the central magnetic leg and a part of the yoke portion are cut and formed at the same time on each side surface of the first and second magnetic legs on the central magnetic leg side along the magnetic leg length direction. A central magnet whose cutting bottom surface has a first side magnetic leg cutout portion and a second side magnetic leg cutout portion having a tapered or curved surface, and the upper surface of the cut yoke portion is flush with the upper surface of the central magnetic leg. The cutting portion of the yoke having the same width as the leg and the notched portion that reaches the middle of the width of the first and second grooves, and the first and second side magnets having a tapered or curved shape from the end of the notched portion An E-shaped core comprising: a yoke portion that is continuous with the leg notch portion;