JP3349018B2 - Induction magnet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction magnet having a core formed by laminating a plurality of plates and a coil mounted on the core.

[0002]

2. Description of the Related Art Generally, in a shell-type transformer,
As shown in FIG. 15, two types of E-type and I-type laminated cores are respectively overlapped to form a block, then joined, and a coil 24 is fitted into a window of the EI core 22 to assemble. In this case, as shown in FIG. 16 (A), for example, for a core material having a width of 60 (arbitrary unit) and a height of 80, two rectangles I each having a width of 10 and a height of 60 are punched, and then the center line O1 is formed. Cutting is performed so that two E-shaped laminated cores LC of 60 × 40 and two I-shaped laminated cores of 60 × 10 are taken. This E shape and I
When the laminated cores LC, LC having the same shape are overlapped to form a block and bonded at the bonding surface M as shown in FIG. 16B, the shape of the EI core is 60 × 50 and the window space is 10 × 30. That is, the aspect ratio (AR) of the window is 3
As a result, two EI cores having a width of 1/3 are produced, and no waste is caused in the core material. Here, in order to make the magnetic resistance of the magnetic path uniform in place, the outer leg 2 of the core is used.
2A, 22B and width 1 of upper and lower connecting portions 22D, 22E
With respect to 0, the width of the middle foot 22C is set to 20.

[0003]

However, the conventional induction magnet has the following problems. As described above, in order to use the core material without waste, the shape of the EI core is formed based on the aspect ratio (AR) 3 of the window. However, since the shape is determined, the size of the core is reduced. In addition, it is difficult to reduce the cost, and it is difficult to reduce the cost by reducing the amount of iron and copper used. This is shown in FIG.
The same applies to the case of cutting a core of 60 (width) × 50 (length) in FIG. 2 (B) with an O 2 line to form two inner cores of 30 × 50 (length) and an aspect ratio (AR) of a window of 3. .

As shown in FIG. 17, when assembling the core 22 and the bobbinless coil 24, the bobbinless coil 2
4 is covered with the insulating sheet 38 and fitted into the core 22. In this fitting, sufficient clearance is provided between the coil 24 and the core 22 so that the insulating sheet 38 is not damaged by corners of the core 22. C was required, and the window area could not be fully utilized.

[0005] In order to solve the above-mentioned problems, the present invention is to prevent the insulating sheet of the coil from being damaged by contacting the core.
And the magnetic resistance of the joint surface between the split cores
It is an object to provide an induction magnet which can be reduced .

[0006]

[MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
The induction electromagnetic device according to claim 1 includes a core formed by joining a plurality of divided core portions to each other, a coil mounted on the core, an insulating sheet covering a surface of the coil, and an outside of the insulating sheet. And a soft magnetic coil cover that covers at least the inner and outer peripheral surfaces of the coil, wherein the coil cover contacts at least one of the divided core portions located therearound,
It forms a magnetic path that bypasses the joint surface between the split core portions.

[0007]

According to the first aspect of the present invention, the soft magnetic coil cover covering at least the inner and outer peripheral surfaces of the coil from the outside of the insulating sheet comes into contact with at least one of the divided core portions located therearound. It forms a magnetic path that bypasses the joint surface between the split core portions. Therefore, the insulating sheet of the coil is not damaged by contact with the core, and a magnetic path is formed between the divided core portions through the coil cover, thereby substantially reducing the magnetic resistance of the joint surface. Can be obtained.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a block diagram of an induction magnet according to a first embodiment of the present invention. This induction magnet is, for example, a shell-type transformer including a core 12 and a coil 14 mounted on the core 12.

The core 12 includes a central foot (hereinafter, middle foot) 12C and left and right foot portions (hereinafter, outer foot) 12C.
A and 12B at their ends at the first and second
Are connected by connecting portions 12D and 12E of
Each of 2A to 12E is formed by superposing a plurality of plate materials (laminate cores) such as a substantially rectangular silicon steel plate. That is, the core 12 is divided into five sections 12A to 12E. The coil 14 is mounted on the middle foot portion 12C, and the outer foot portions 12A, 12B and the two connection portions 12D, 12C.
It is located in a rectangular window 15 surrounded by E.

Here, in the core of the first reference example , when the horizontal dimension w of the window portion 15 is 1, the vertical dimension h is arbitrarily set, and the horizontal dimension W of the outer shape of the core is set to 6 H is h + 2
Are set respectively. In other words, it is a core in which the aspect ratio (AR) of the window is arbitrarily set. This core is
The outer dimensions are horizontal dimension W6 x vertical dimension H5, and the window aspect ratio (A
R) While maintaining the same properties as the conventional core of 3, the iron and copper materials can be saved. FIG. 2 shows an example of this core. The core 12 has a width w of the window 15.
Is 1, the vertical dimension h is 2, the horizontal dimension W of the external shape of the core is 6, and the vertical dimension H is 4, that is, the external size is the horizontal dimension W6 × the vertical dimension H4, and the aspect ratio of the window is (AR)
Is set to 2.

When the conventional core has a width 10 and a thickness D of the outer foot portion 22A as shown in FIG. 16, the core 12 has the same thickness D under the same thickness D. 10. The width (same as the lateral dimension w) of the outer foot portion 12A is set so as to have characteristics.
This width is not limited to this as long as the thickness D is different. The reason why the joining surface M of each of the portions 12A to 12E is formed in an uneven shape will be described later.

The outer feet 12A and 12B are horizontal 11.2
(Arbitrary unit: the same applies hereinafter) × rectangle 22.4 rectangle. The midfoot portion 12C is a rectangle having a width of 22.4 × length 22.4. The first and second connecting portions 12D and 12E are provided with a horizontal 67.
It is a rectangle of 2 (11.2 × 6) × 44.8 (11.2 × 4) height. When these laminated cores are joined after being overlapped and formed into a block, the outer dimensions are 67.2 (1
1.2 × 6) × length 44.8 (11.2 × 4), that is, the outer shape of the core is the horizontal dimension W6 × the vertical dimension H4, and the window space is 11.2 × the horizontal 22.4, ie, the window Aspect ratio (A
R) becomes the core 12 of 2.

The magnetic circuit CK of the core 12 is as shown in FIG. When the magnetic flux density B = constant, the winding DC resistance = constant, the core thickness D = constant, and the outer foot width shown in FIG. 3 is u, the middle foot width is v, and the window width is w, 1 / 2v = u FIG. 4 shows the calculation result of the change in the total weight of the iron and copper materials of the transformer with respect to the change in the aspect ratio (AR) of the window under the condition of = w. The solid line indicates the total weight of iron and copper, the dashed line indicates the weight of iron, and the dotted line indicates the weight of copper. FIG. 5 is an enlarged view of FIG.
Shown in As shown in this figure, this core has a total weight of iron and copper when the window aspect ratio (AR) is in the range of 2 <AR <3, as compared with the conventional core having the window aspect ratio (AR) 3. Becomes smaller. Preferably, 2.3 <AR <
Cores in the 2.7 range have a sufficiently low total weight of iron and copper.

By the way, although the AR is in the range as described above in reducing the weight of the transformer, in order to reduce the cost of the transformer, the cost of the core (iron) and the cost of the coil (copper) with the same weight are reduced. It is also necessary to consider the ratio of
For example, if the ratio of the cost of copper to the cost of iron at the same weight is 4, a curve as shown by the thick line in FIG. 5 is drawn, and the lowest point of the cost shifts to AR = 1. In other words, the ratio of the unit price of copper and iron changes due to changes in the market conditions, so that the value of AR for reducing costs also changes. Considering the unit price ratio of copper and iron (3.5-4.5) from the past 10 years, 1.5 ≦ AR <
The cost can be reduced at 2.5. In addition, since the aspect ratio (AR) of the window can be set arbitrarily in this core, while maintaining the same characteristics as the conventional core having an aspect ratio (AR) of 3 without wasting the core material,
A low-profile induction magnet can be formed.

Next, the state of the joint surface M of the core 12 divided into five parts will be described. In FIG. 2, the feet 12A to 12A
A rectangular concavo-convex portion is formed on a joint surface M between the end of C and the two connecting portions 12D and 12E, and the concave-convex portion is press-fitted in a direction orthogonal to the joint surface M. In this case, the joining surfaces M are joined by pressing with zero clearance (zero gap tolerance).

This is an improvement over the conventional fitting method shown in FIG. In the method of FIG. 6 (A), the I-shaped core is moved in the direction of the arrow to the E-shaped core having an uneven joint surface M provided with an undercut U between the left and right feet of the laminated core and the I-shaped core. At the time of press-fitting, the E-shaped core is deformed and fitted so as to reduce the distance between the legs of the E-shaped core due to the elasticity of the core material. In the method (B), since the I-type core is inserted from the side surface in the direction perpendicular to the paper surface into the E-shaped core having the substantially mushroom-shaped joining surface M, the gap between the joining surfaces M is reduced and inserted in parallel. It was difficult to do. For this reason, although the contact area of the joining surface M becomes large, the effect is offset by the gap, and the magnetic resistance cannot be reduced. The present invention has solved such a conventional problem.

In this example, the depth of the unevenness is 1 mm or more, and the ratio of the width to the depth of the unevenness is 1: 1. Therefore, the contact area of each part is twice as large as the case where no unevenness is provided. This is because, compared to the conventional core 22 in which the joint surface is only one end of the foot portion, the core 12 has the joint surface at both ends of the foot portion, and the influence of the gap G is doubled. Since the contact area is doubled as described above, the magnetic resistance at the junction is halved, so that this effect can be offset. In addition,
When the depth of the unevenness is further increased, the contact area increases, and the influence of the gap G can be further reduced. As described above, by making the bonding surface M uneven, the area of the bonding surface M can be increased and the magnetic resistance can be reduced.

FIG. 7 shows a punched state of the core material at this time.
Shown in FIG. 7A shows a state in which the first connecting portion 12D and the second connecting portion 12E are used for material pick-up, and the connecting portions 12D and 12D are provided on both sides of the uneven portion serving as the joining surface M.
Take E and press cut at the uneven part. The minute portion in FIG. 70 where the bonding surface M is not formed is discarded. (B) is the midfoot 12
C of (C) shows the state of material picking of the outer foot parts 12A and 12B, and the middle foot part 12C and the outer foot parts 12A and 12B are taken on both sides of the uneven part which also becomes the joint surface M, Press cut at the part. As described above, since each of the five divided parts used for this laminated plate is rectangular,
By cutting a silicon steel plate having a predetermined width WT1 to WT3 as shown in this figure, each part can be obtained without waste. Therefore, as in the case of the conventional EI type core, almost no waste occurs in the core material.

As described above, the unevenness is provided on the joint surface M of the core 12 to increase the contact area to reduce the magnetic resistance, and is conventionally fixed by bonding or welding by press-fitting with zero fitting. However, a firm connection can be obtained by one-touch press-fitting.

As a result, the outer shape of the first reference example is
7.2 × 44.8 vertical window space 11.2 × 22.4 vertical
In (AR2), the core 12 having the unevenness on the bonding surface M has an outer shape of 60 × 50 and a window space of 10 × 30 (AR
When compared with the conventional core 22 of 3) under the same stack thickness D, the core is downsized while having the same performance as the conventional core, the iron amount is increased by about 3.2%, and the copper amount is increased by about 11.8%. Will be reduced. Therefore, a robust and lightweight transformer is manufactured.

It should be noted that the outer core of 6 × 4 in FIG.
Even when cutting with three lines and creating two horizontal 3: vertical 4 core-shaped cores in which coils are attached to both left and right legs,
The same effect can be obtained as compared with the conventional inner core of 3: 5 in length.

FIG. 8 shows an example in which the transformer of FIG. 1 is used as a leakage transformer. 8A to 8D show a front view, a right side view, a plan view, and a perspective view of the core 12 with a coil. In FIG. 8D, the leakage core 16 is provided between the primary winding 14P and the secondary winding 14S of the coil.
Is provided. The back view of the core 12 is the same as the front view, the left side view is the same as the right side view, and the bottom view is the same as the plan view.

Next, a second reference example will be described. FIG.
(A) shows a front view of the core 32 of the induction electromagnetic device of the second reference example . Since the aspect ratio (AR) of the window of the core 32 is m, when the horizontal dimension w of the window 15 is 1, the vertical dimension h of the window 15 is m, and the horizontal dimension W of the outer shape of the core is m. 6
The vertical dimension H of the outer shape of the core is set to m + 2. M of the core 32 also satisfies 1.5 ≦ AR <3. The core 32 includes a middle foot portion 32C surrounded by a two-dot chain line, and outer foot portions 32A, B on both left and right sides thereof.
And a first connecting portion 32D and a second connecting portion 32E connected at both ends thereof. The divided core portions forming these are not divided into five rectangles as in the first embodiment, but are divided into three divided core portions A, B, and C indicated by solid lines. These divided cores A, B, and C are also formed by laminating a plurality of plate members in the same manner as described above. A coil (not shown) is mounted on the window 15 of the core 32.

The split core portion A has a body portion A extending in the lateral direction.
It has an L-shape consisting of 1 and a first leg A2 extending downward, and has a horizontal dimension of 2 and a vertical dimension of m + 2. Also,
The split core portion B has an L-shape including a body portion B1 extending in the lateral direction and a first leg portion B2 extending below the body portion B1, and similarly has a lateral size of 2 and a vertical size of m + 2. The split core portion C has a T-shape composed of a body portion C1 extending in the lateral direction and a second leg portion C2 extending above the center thereof, and has a horizontal dimension of 4 and a vertical dimension of m + 2.

The core 32 has split core portions A and B arranged symmetrically to each other, and a split core portion C is arranged so as to cut between them. The split core portion A and the split core portion C are arranged such that the front end surface of the body portion A1 of the split core portion A abuts on the corresponding one side surface of the left end of the second leg C2 of the split core portion C, and One side of the tip of the first leg A2 of the portion A is abutted against the corresponding tip of the second leg C1 of the split core portion C. Further, the split core portion B and the split core portion C abut the front end surface of the body portion B1 of the split core portion B against one corresponding side surface of the right end of the second leg C2 of the split core portion C, One side surface of the tip of the first leg B2 of the split core portion B is abutted against the corresponding tip surface of the second leg C1 of the split core portion C. This allows
The area (cross-sectional area) of the magnetic path of the middle foot is twice as large as that of the outer foot and the connecting part, and the magnetic resistance is kept uniform over the entire core.

Since the aspect ratio (AR) m of the window can be arbitrarily set by the divided core portions A, B, and C, the core 32 satisfies 1.5 ≦ AR <3 to reduce the weight and cost. It is possible to easily form a low-profile induction magnetic device or the like while maintaining the same performance as the conventional induction magnetic device or the conventional one. In addition, the core can be manufactured without waste by the manufacturing method of the core described later. Further, the joint surface M of the core 32 is 1
Since the magnetic core is the same as the conventional core 22 at two locations in one magnetic path, the gap of the magnetic path is also the same, and the magnetic resistance does not increase. Therefore, as in the first reference example , the weight of the iron and copper materials can be reduced and the transformer can be reduced in weight while maintaining the same performance as that of the related art, without providing any irregularities on the joining surface.

A method for manufacturing the above-described core 32 of the induction ceramic will be described below. In FIG. 9B, first, a rectangular area having a horizontal dimension of 4 and a vertical dimension of m + 3 is set on the original plate P.
With the lower left corner of this rectangular area as the origin (0, 0), X
The axis and the Y axis are set vertically. In this case, the original plate P has a height of m + 3.
Although the one extending in the X direction is used, a one having a height of 4 and extending in the Y direction may be used.

On the XY coordinates, coordinates a (0, 1), b
(1, 1), c (1, m + 2), d (2, m + 2), e
(2, m + 3), f (3, m + 2), g (3,1), i
Take (4,1) and cut lines X1, b connecting coordinates a and b
Cutting line Y1 connecting c and c, cutting line X connecting c and f
2, a cutting line Y2 connecting d and e, a cutting line Y3 connecting f and g, and a cutting line X3 connecting g and i are respectively set.
Then, while cutting out the rectangular area from the original plate P,
The cutting is performed along the cutting lines X1 to X3 and Y1 to Y3.
In this way, the divided core portions A, B, and C are extracted from the rectangular area having the horizontal dimension 4 and the vertical dimension m + 3 set on the original plate P. The core 32 is assembled by abutting these divided core portions A, B, and C as shown in FIG. 9A.

As described above, all of the divided core portions A, B, and C constituting the core 32 having the window aspect ratio (AR) m can be obtained from the original plate P shown in FIG. become. For example, when the aspect ratio (AR) of the window is 2, if the original plate P has a horizontal dimension of 4 and a vertical dimension of 5, a core having an external size of W6 × H4 can be obtained without waste of material.

Next, an induction electromagnetic device according to an embodiment of the present invention will be described.
The vessel will be described. In this example, conventionally, a coil cover 36 is used which solves the problem that the window area of the core could not be sufficiently utilized by providing a clearance between the coil and the core to prevent breakage of the insulating sheet. .

The coil covers 36, 36, 36, 36
Is the same material as the laminated core (for example, silicon steel plate)
As shown in FIG. 10, a first side wall 42, a second side wall 44 parallel to the first side wall 42, and both side walls 42,
A connecting wall 46 is provided between the connecting walls 44. Further, the first side wall 42 and the second side wall 44 have bent pieces 48, 48 at the distal ends thereof, respectively. The length t of the connecting wall 46 is substantially the same as the width t of the coil surface of the primary winding 14P and the secondary winding 14S of the bobbinless coil 14.

First, the primary winding 14P and the secondary winding 14
The insulating sheets 38 are wound on both sides of S. Next, the primary windings 14P are arranged in such a manner that the bent pieces 48 of the coil cover 36 are spread from each other so that
The coil covers 36 are fitted to cover the insulating sheet 38 of the bobbinless coil 34 from top to bottom. Thereby, the insulating sheet 38
The surface of the coil 14 is covered with a coil cover 36. As shown in FIG.
When it is fitted in the core 12, it is not damaged by the corner of the core 12.

The coil cover 36 comes into contact with the outer foot portions 12A, 12B, the middle foot portion 12C, or both connecting portions 12D, 12E of the divided core portions located around the coil cover 36 to form a joint surface between the divided core portions. A magnetic path that bypasses the magnetic path.
For example, in FIG. 11 (B), a part of the magnetic flux passing through the coil cover 36 from the outer foot portion 12A passes through the upper second connection portion 12E, and the other portion goes around the coil cover 36 and the middle foot portion. Exit to 12C. Therefore, this coil cover 36
As a result, a magnetic path is formed between the outer foot portion 12A, the second connecting portion 12E, and the middle foot portion 12C.
Is bypassed, and the magnetic resistance of the core 12 can be substantially reduced.

Further, the coil cover 36 may be made of a laminated plate as shown in FIG. 12B, instead of a single plate as described above. As shown in FIG. 12A, the coil cover 36 is formed by combining substantially U-shaped plate members 52 to 58 in the direction of the arrow. First, the inner plate members 54 and 56 are butted with the coil 14 interposed therebetween,
Next, the outer plate members 52 and 58 are assembled by abutting each other. Accordingly, it is not necessary to expand the bent piece 48 of the coil cover 36, and each plate material is unlikely to come off. Also, the butted portion M1 of the inner plates 54 and 56 and the outer plate 5
Since the butting portions M2 of the coils 2 and 58 are provided with their positions shifted from each other, an increase in the magnetic resistance of the magnetic path due to the gap between the butting portions M1 and M2 of the coil cover 36 is suppressed.

FIG. 13 is a front view when the coil cover 36 is used for a leakage transformer. As shown in this figure, the primary windings 1 covered with the coil covers 36, respectively.
A leakage core 16 in which silicon steel plates are laminated is provided between the 4P and the secondary winding 14S, and the leakage core 16 is not covered with a cover. In this leakage transformer, when both the windings 14P, 14S and the leakage core 16 are covered by a single large coil cover, both ends 16A, 16A,
From 16B toward outer foot 12A and middle foot 12C,
Alternatively, a magnetic flux directed in the opposite direction causes a large eddy current loss in a coil cover having a large surface orthogonal to the magnetic flux. For this reason, in FIG. 11, the coil cover 36 is formed by dividing the primary winding 14P and the secondary winding 14S, respectively, so that the coil cover 36 does not face both ends 16A and 16B of the leakage core 16. The generation of eddy current loss is prevented. In the case of a transformer that is not a leakage transformer, the coil cover 36 may be integrally formed without being divided as shown in FIG.

In this embodiment, a transformer is shown as an induction magnet, but the present invention can be applied to a choke.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing an induction magnet according to a first reference example of the present invention.

FIG. 2 is a diagram showing an example of the configuration of the core.

FIG. 3 is a diagram illustrating a dimensional relationship of a core;

FIG. 4 is a diagram showing a relationship between the aspect ratio of the window of the induction ceramic and the volumes of iron and copper materials of the transformer.

FIG. 5 is an enlarged view of FIG. 4;

FIG. 6 is a view showing a known core fitting method.

FIG. 7 is a view showing a punched state of a core material.

FIG. 8 is a front view, a right side view, a plan view, and a perspective view with a coil of the core.

FIG. 9 is a front view of a core of an induction magnet according to a second reference example ;
FIG. 3 is a view showing a plate material of a material of the core.

FIG. 10 is a perspective view showing a coil cover of the induction electromagnetic device according to one embodiment of the present invention .

FIG. 11 is a front view showing an induction magnet having a coil cover.

FIG. 12 is a perspective view showing a coil cover according to another embodiment.

FIG. 13 is a front view showing a leakage transformer having a coil cover.

FIG. 14 is a front view showing an integrated coil cover.

FIG. 15 is a schematic perspective view showing a conventional induction magnet.

FIG. 16 is a view showing a state in which a conventional core material is punched.

FIG. 17 is a diagram showing a state where an insulating sheet is wound around a conventional coil.

[Explanation of symbols]

12: core, 12A, 12B: outer foot, 12C: middle foot, 12D: first connection, 12E: second connection, 1
4 ... coil, 15 ... window , 36 ... coil cover .

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takahiko Adachi 5-4 Techno Park, Sanda-shi, Hyogo Tabuchi Electric Co., Ltd. (72) Inventor Yasushi Yasushi 5-4 Techno Park, Sanda-shi, Hyogo Tabuchi Electric Co., Ltd. (72) Inventor Takenari Higashinaka 5-4 Techno Park, Mita City, Hyogo Prefecture Inside Tabuchi Electric Co., Ltd. (56) References JP-A-4-322415 (JP, A) JP-A 63-108618 (JP, U)

Claims (1)

(57) [Claims] 1. A core formed by joining a plurality of divided core portions to each other, a coil mounted on the core, an insulating sheet covering a surface of the coil, and at least an inner and outer periphery of the coil from outside the insulating sheet. A soft magnetic coil cover that covers the surface, wherein the coil cover contacts at least one of the divided core portions located therearound to form a magnetic path that bypasses a joint surface between the divided core portions. Inductive porcelain.