WO2007039939A1

WO2007039939A1 - Core having insulating sheet and electric device provided with such core

Info

Publication number: WO2007039939A1
Application number: PCT/JP2006/303273
Authority: WO
Inventors: Yoshiyuki Tabata; Ryoichi Takami; Shinsuke Shimabayashi
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2005-10-05
Filing date: 2006-02-23
Publication date: 2007-04-12
Also published as: CN101091227B; CN101091227A; JPWO2007039939A1; JP4325673B2

Abstract

In a core having an insulating sheet and an electric device provided with such core, a bobbin is inserted into one section of the core which is composed of at least two sections, and at the same time, a substantially strip-like insulating sheet bent in substantially T shape or L shape is inserted. An unbent portion of the insulating sheet is arranged along the surface of the core. The other section of the core is inserted into the bobbin to have the bent portion of the insulating sheet sandwiched with the facing portions of the core.

Description

Specification

Core having insulating sheet and electric device including the same

Technical field

The present invention mainly relates to a core having an insulating sheet and an electric device such as a transformer provided with the core.

Background art

A configuration of an iron core as an example of a conventional core and a configuration of a transformer including the core will be described with reference to FIG. In Fig. 12, when forming the air gap 10 (hereinafter referred to as gap 10) of the E-shaped iron core 9 that constitutes the transformer, when the pair of E-shaped iron cores 9 are brought into contact with each other, the center is the center The gap 10 is formed by cutting the part so that the central parts do not contact each other.

As another example, as shown in FIG. 13, when a U-shaped core 1 is used, a gap material 11 is inserted into a butt portion of a pair of U-shaped cores 1 facing each other. A gap is formed by attaching the gap material 11 to both U-shaped cores 1. Note that the characteristics of the transformer can be changed by changing the thickness of the gap material 11 to be inserted or by using the gap material 12 having different characteristics from the gap material 11.

[0004] As another example, as shown in Fig. 14, a structure in which several gap materials 14 or 15 are inserted into the gap portion of the circular core 13, and the characteristics of the transformer are combined by the combination of the gap materials 14, 15 is shown. Are known (see, for example, JP-A-2002-75747).

[0005] However, with the above-described conventional iron core and the transformer including the same, it is necessary to form a gap! There are the following problems.

In FIG. 12, by cutting the E-shaped core 9, a gap 10 is formed when one set of the E-shaped core 9 is combined. Therefore, it is extremely difficult to change the size of the gap 10 by cutting the iron core when assembling the transformer. When changing the type of gap 10 in a small-lot production transformer, it is necessary to change the design of the E-shaped iron core 9 so that it matches the various gaps 10. Therefore, sharing There is a problem in terms of cost.

[0007] In addition, in the example using the U-shaped core 1 shown in Fig. 13, the U-shaped core 1 is replaced by arranging the gap materials 11 and 12 on the contact surface of the U-shaped core 1 at the time of creating the transformer. The thickness of the gap between the iron cores 1 can be changed. However, in order to change the thickness of the gap material 11, it is necessary to prepare multiple types of gap materials 12 in which the thickness of the material itself is changed.

[0008] Further, in the example using the circular iron core 13 shown in Fig. 14, the characteristics of the transformer can be changed by changing the material of the several gap materials 14 and 15 to be inserted. However, in order to change the characteristics of a transformer, several types of gap materials with different characteristics must be prepared.

[0009] As described above, in the conventional iron core and transformer, the number of parts and types of gap materials are increased, and in addition, the number of assembling steps such as requiring a pasting work for fixing a plurality of gap materials is required. Parts cost will increase.

Furthermore, in the examples of the U-shaped core 1 shown in FIG. 13 and the circular core 13 shown in FIG. 14, when assembling the transformer, the surroundings of each gap material are covered with parts such as bobbins forming coils. In such a case, it is impossible to confirm whether the gap material is inserted after assembly of the transformer! Therefore, it can be confirmed that the gap material is not included only after the transformer is assembled into the product after the transformer assembly is completed and the characteristics of the product are confirmed. In addition, if it is not possible to find a gap material forgotten due to the characteristics of the product, the product may be distributed to the factory as it is.

Disclosure of the invention

The core having the insulating sheet of the present invention is a core having at least two partial forces, and a gap between the cores is formed by sandwiching a bent portion (hereinafter referred to as a bent portion) of the insulating sheet between the cores. Then, an unbent portion of the insulating sheet (hereinafter referred to as a non-bent portion) is placed along the surface of the core. The insulating sheet has a substantially strip shape bent into a substantially T-shape or a substantially L-shape, or a substantially strip shape folded into at least two opposing substantially L-shapes.

[0012] According to the core having the insulating sheet of the present invention, it is necessary to change the gap itself depending on the thickness and material of the gap material without changing the shape of the core depending on the type of the electrical equipment. There is no. In addition, it is possible to confirm that gap materials are forgotten to be inserted, reducing assembly man-hours and component costs, and improving quality stability.

Brief Description of Drawings

FIG. 1 is an external view of a U-shaped iron core according to a first embodiment of the present invention.

FIG. 2 is an assembly diagram of a belt-like sheet, a U-shaped iron core, and a bobbin according to Embodiment 1 of the present invention.

FIG. 3 is an external view of a belt-like sheet according to Embodiment 1 of the present invention.

FIG. 4 is an external view showing a state in which the belt-like sheet, the U-shaped iron core, and the bobbin according to Embodiment 1 of the present invention are assembled.

FIG. 5 is an external view showing a state in which the belt-like sheet in Embodiment 2 of the present invention is bent twice.

FIG. 6 is an external view of a belt-like sheet according to Embodiment 3 of the present invention.

FIG. 7 is an assembly diagram of a belt-like sheet, a U-shaped iron core, and a bobbin according to Embodiment 3 of the present invention.

FIG. 8 is an external view showing a state in which the belt-like sheet, the U-shaped iron core, and the bobbin are assembled in the third embodiment of the present invention.

FIG. 9 is an external view of a belt-like sheet according to Embodiment 4 of the present invention.

FIG. 10 is an assembly diagram of a belt-like sheet, a U-shaped iron core and a bobbin according to Embodiment 4 of the present invention.

FIG. 11 is an external view showing a state in which a belt-like sheet, a U-shaped iron core, and a bobbin are assembled according to Embodiment 4 of the present invention.

FIG. 12 is an external view of a conventional E-shaped iron core.

FIG. 13 is a schematic diagram for explaining a gap thickness change of a conventional U-shaped core.

FIG. 14 is a schematic diagram for explaining a change in gap material of a conventional circular iron core. Explanation of symbols

[0014] 1 U-shaped iron core

2 Strip sheet 3A V-shaped bend

3B Unfolded part

4 Bobbin

5 Coil terminal

6 Kiak

7 Screw

8A continuous V-shaped fold

8B Unfolded part

9 E-shaped iron core

10 Air gap

11, 12 Gap material

13 Circular iron core

14, 15 Gap material

16 Strip sheet

17A L-shaped bend

17B Unfolded part

BEST MODE FOR CARRYING OUT THE INVENTION

[0015] (Embodiment 1)

Hereinafter, Embodiment 1 of the present invention will be described with reference to FIGS. Figure 1 is an external view of a set of U-shaped iron cores 1 that make up an iron core that is an example of a core. Fig. 2 shows a U-shaped iron core 1, a belt-like sheet 2 to be described later, a V-shaped bent portion 3A of the belt-like sheet 2, and an unfolded portion of the belt-like sheet 2 (a portion other than the V-shaped bent portion 3A, hereinafter FIG. 5 is an explanatory diagram for explaining gap formation of an iron core composed of a bobbin 4 and a non-bent portion 3B. FIG. 3 is an external view of the belt-like sheet 2. FIG. 4 is an external view showing a state in which the belt-like sheet 2, the U-shaped iron core 1 and the bobbin 4 are assembled.

[0016] Hereinafter, the gap formation of the iron core in the first embodiment will be described.

[0017] As shown in Figs. 1 and 2, for example, a pair of U-shaped iron cores 1 are configured to face each other. In addition, as shown in Fig. 2 and Fig. 3, near the center of the belt-like sheet 2 made of an insulating material Is formed with a V-shaped bent portion 3A. As will be described later, when the V-shaped bent portion 3A is sandwiched between the U-shaped iron cores 1, the overall shape of the belt-like sheet 2 is substantially T-shaped. In addition, as shown in FIG. 2, the depth of the V-shaped bent portion 3 A of the belt-like sheet 2 is substantially equal to the thickness of the U-shaped core 1. The area of the portion of the V-shaped bent portion 3A facing the cross section of the U-shaped iron core 1 may be equal to or greater than the cross-sectional area of the U-shaped iron core 1. As the belt-like sheet 2, a material that is magnetically nonmagnetic and electrically insulative is used.

[0018] Next, assembly of a transformer, which is an example of an electric device including an iron core, will be described.

When assembling the transformer, for example, as shown in FIG. 2, a bobbin 4 for winding a winding to form a coil is prepared. Insert bobbin 4 into U-shaped iron core 1 located at the bottom in Fig. 2, and insert belt-like sheet 2 at the same time. At this time, the V-shaped bent portion 3A is arranged so as to be in the position of the cross section of the U-shaped core 1. The unbent portion 3B of the belt-like sheet 2 is placed along the outer surface portion of the U-shaped iron core 1 below. Then, the upper U-shaped iron core 1 is inserted into the bobbin 4 so that the V-shaped bent portion 3 A of the belt-like sheet 2 is sandwiched between the butted portions of the U-shaped iron core 1 positioned below and above in FIG. To do.

[0020] After that, as shown in FIG. 4, in the state where the V-shaped bent portion 3A (not shown) of the belt-like sheet 2 is sandwiched between a pair of U-shaped iron cores 1, A pair of U-shaped iron cores 1 are fixed by fastening with screws 7. Then, a coil is formed by performing a winding on the bobbin 4 to constitute a transformer.

[0021] It should be noted that here, an example in which a pair of U-shaped iron core 1 and strip-like sheet 2 is inserted into bobbin 4 is formed. A coil is formed by performing a winding on bobbin 4, and this coil is formed into a U-shape. You can insert the iron core 1 and the belt-like sheet 2.

[0022] The length of the belt-like sheet 2 is such that when sandwiched by the U-shaped iron core 1, the whole length of the unfolded portion 3B is longer than the bobbin 4 and the coil, and the belt-like sheet 2 is visible from the outside. It only suffices.

[0023] The operation of the transformer configured as described above will be described.

[0024] As shown in FIG. 2, when assembling a pair of U-shaped iron core 1, bobbin 4, and strip-like sheet 2, V of strip-like sheet 2 formed by folding a part of strip-like strip-like sheet 2 Shaped bending Part 3A is sandwiched between a pair of U-shaped cores 1. Therefore, the work of attaching the belt-like sheet 2 to the U-shaped iron core 1 is not necessary and is naturally fixed between the pair of U-shaped iron cores 1. Further, the belt-like sheet 2 exists inside the bobbin 4. For this reason, even if the V-shaped bent part 3 A of the belt-like sheet 2 is disengaged from the abutting portion of the U-shaped iron core 1, the inner shape of the bobbin 4 is cylindrical. It is held so that it does not deviate from the butted part of the iron core 1.

Further, as shown in FIG. 4, when the pair of U-shaped iron core 1, bobbin 4 and belt-like sheet 2 are assembled, the unfolded portion 3 B of the belt-like sheet 2 protrudes outside the bobbin 4. It has become. Here, bobbin 4 force When external mechanical force is applied to coil terminal 5 that serves as a lead wire from a coil (not shown) exposed to the outside, coil terminal 5 and U-shaped There is a possibility of contact with the type iron core 1. However, as in the first embodiment, the belt-like sheet 2 is arranged between the coil terminal 5 and the U-shape by the configuration in which the unfolded portion 3B of the belt-like sheet 2 is located between the U-shaped iron core 1 and the coil terminal 5. It is possible to electrically insulate from the mold core 1.

[0026] Furthermore, as shown in FIG. 4, the presence of the belt-like sheet 2 that protrudes outside the bobbin 4, so that when the transformer is incorporated into the product, the V-shaped folding that is a part of the belt-like sheet 2 is performed. It is possible to visually confirm whether the part 3 A is correctly inserted between the U-shaped iron cores 1 and a gap is formed between the U-shaped iron cores 1!

[0027] Note that the method of fixing the pair of U-shaped cores 1 shown in Fig. 4 is an example, and the U-shaped core 1 is directly attached to the tape or string without using the quill 6 and the screw 7. It may be fixed. Alternatively, it may be fastened with a band-shaped component along the outer shape portion of the U-shaped iron core 1.

[0028] As described above, according to the first embodiment, the belt-like sheet 2 is fixed by adopting a configuration in which the V-shaped bent portion 3A of the belt-like sheet 2 is sandwiched between the pair of U-shaped iron cores 1. Can do. This eliminates the need for pasting the material for forming the gap between the U-shaped iron cores 1 on the U-shaped iron core 1 as in the prior art, improving workability. Further, since it is not necessary to attach a member for forming the gap to the U-shaped iron core 1, the dimension of the gap can be changed relatively easily by replacing the belt-like sheet 2 or the like.

Further, as shown in FIG. 2, since the belt-like sheet 2 exists inside the bobbin 4, the belt-like sheet Even when the V-shaped bent part 3A of 2 becomes disengaged from the butt portion of the U-shaped iron core 1, the belt-like sheet 2 does not release the butt portion force of the U-shaped iron core 1. This is because the internal shape of the bobbin 4 is cylindrical, and the space between the belt-like sheet 2 and the bobbin 4 is not so large. Therefore, the thickness of the gap which is the V-shaped bent portion 3A of the belt-like sheet 2 can be stably maintained.

[0030] As shown in FIG. 4, when the pair of U-shaped iron cores 1, the bobbin 4, and the belt-like sheet 2 are assembled, the unbent portion 3B of the belt-like sheet 2 protrudes outside the bobbin 4. Therefore, it is possible to electrically insulate between the coil terminal 5 and the U-shaped iron core 1 by the belt-like sheet 2. As a result, electrical leakage is prevented and a safer transformer can be configured. Furthermore, since the structure can visually confirm whether or not the gap of the belt-like sheet 2 is inserted, it is possible to prevent the gap from being forgotten.

[0031] (Embodiment 2)

In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

[0032] The difference from the first embodiment is that, as shown in Fig. 5, a continuous V-shaped bent portion 8A is formed by bending a part of the belt-like sheet 2 also having an insulating material force, and this continuous V-shaped bent portion. 8A is used to form a gap between U-shaped iron cores 1. In this manner, by using the belt-like sheet 2 on which the continuous V-shaped bent portion 8A is created, the gap thickness can be doubled as compared with the belt-like sheet 2 of FIG. In addition, if the V-shaped bent portion is additionally provided, the gap thickness can be easily changed.

Hereinafter, the transformer according to the second embodiment will be described.

[0034] The force of the bent portion of the belt-like sheet 2 is different. As shown in Fig. 2, when the U-shaped iron core 1, the bobbin 4 and the belt-like sheet 2 are assembled, the continuous V-shaped bent portion 8A of the belt-like sheet 2 is The belt-like sheet 2 is sandwiched between the U-shaped iron cores 1 and is naturally fixed without any pasting work. Furthermore, since the belt-like sheet 2 exists inside the bobbin 4 whose inner shape is cylindrical, the belt-like sheet 2 does not deviate from the butt portion of the U-shaped iron core 1.

Further, as shown in FIG. 4, when the U-shaped iron core 1, the bobbin 4, and the belt-like sheet 2 are assembled, the unbent portion 8 B of the belt-like sheet 2 has a structure that protrudes outside the bobbin 4. This Due to this structure, the bobbin 4 force When the external force mechanical force is applied to the coil terminal 5 exposed to the outside, there is a possibility that the coil terminal 5 and the U-shaped iron core 1 may touch. The coil terminal 5 and the U-shaped iron core 1 can be electrically insulated.

[0036] Further, as shown in FIG. 4, the presence of the strip-shaped sheet 2 protruding outside the bobbin 4, the continuous V-shaped bent portion 8A of the strip-shaped sheet 2 is geared when the transformer is incorporated into the product. You can visually check whether it is inserted as.

[0037] Although the gap thickness can be easily changed by increasing the number of times the continuous V-shaped bent portion 8A is bent, at least the belt-like sheet 2 is considered to be exposed to the bobbin 4 force. And hope to increase the number of bending.

[0038] As described above, according to the second embodiment, since the belt-like sheet 2 is naturally fixed without performing the pasting operation, the gap of the continuous V-shaped bent portion 8A of the belt-like sheet 2 is reduced. There is no need to paste. If the number of V-shaped folding of the belt-like sheet 2 is changed, it is possible to cope with the formation of gaps with various thicknesses.

[0039] (Embodiment 3)

In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and detailed description thereof is omitted.

[0040] The difference from Embodiment 1 is that, as shown in Fig. 6, a part of the sheet is folded as a band-like sheet 16 having insulating material strength to form an L-shaped bent portion 17A, and an L-shaped band-like sheet is formed. This is the point on Sheet 16. This L-shaped bent portion 17A is used for forming a gap between the U-shaped iron cores 1. In this way, by using the belt-like sheet 16 in which the L-shaped bent portion 17A is formed, the length of the belt-like sheet 2 can be halved compared to the belt-like sheet 2 shown in FIG.

Hereinafter, the transformer according to the third embodiment will be described.

[0042] As shown in FIG. 7, when the U-shaped iron core 1, the bobbin 4 and the belt-like sheet 16 are assembled, the L-shaped bent portion 17A of the belt-like sheet 16 is sandwiched between the U-shaped iron core 1 and the belt-like sheet 16 Is fixed naturally without any pasting work. Furthermore, since the belt-like sheet 16 exists inside the bobbin 4 whose inner shape is cylindrical, even if the L-shaped bent portion 17 A of the belt-like sheet 16 deviates from the abutting portion of the U-shaped iron core 1, the belt-like sheet 16 Sheet 16 is U-shaped iron core It will not come off from the butt of 1.

Further, as shown in FIG. 8, when the U-shaped iron core 1, the bobbin 4, and the belt-like sheet 16 are assembled, the unfolded portion 17 B of the belt-like sheet 16 protrudes outside the bobbin 4. ing. With this structure, the bobbin 4 force When the externally applied mechanical force is applied to the coil terminal 5 exposed to the outside, the coil terminal 5 and the U-shaped iron core 1 may come into contact. Thus, the coil terminal 5 and the U-shaped iron core 1 can be electrically insulated.

[0044] Further, as shown in FIG. 8, the presence of the belt-like sheet 16 protruding outside the bobbin 4 indicates whether or not the gap of the belt-like sheet 16 is inserted when the transformer is incorporated into the product. It can be confirmed visually.

[0045] As described above, according to the third embodiment, as shown in FIG. 7, the belt-like sheet 16 is naturally fixed without performing an attaching operation. There is no need to paste the gap which is the bent portion 17A.

[0046] Further, as shown in FIG. 7, since the belt-like sheet 16 is held away from the butted portion of the U-shaped iron core 1, the thickness of the gap which is the L-shaped bent portion 17A of the belt-like sheet 16 Can be kept stable.

In addition, as shown in FIG. 8, the coil terminal 5 and the U-shaped iron core 1 can be electrically insulated by the belt-like sheet 16, so that a safer transformer can be configured by preventing leakage and the like. .

[0048] Further, as shown in FIG. 8, since the structure can visually confirm whether or not the gap of the belt-like sheet 16 is inserted, it is possible to prevent a gap from being forgotten.

[0049] (Embodiment 4)

In the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and detailed description thereof is omitted.

[0050] The difference from the first embodiment is that, as shown in Fig. 9, a part of the belt-like sheet 16 is folded as a belt-like sheet 16 to form an L-shaped bent portion 17A so as to face each other. This is the point. In this way, when the belt-like sheet 16 having the L-shaped bent portion 17A is used in combination with the direction, the belt-like sheet at the time of assembly is compared with the belt-like sheet 2 shown in FIG.

It can be assembled with 16 divided. [0051] Hereinafter, a transformer according to the fourth embodiment will be described.

[0052] As shown in FIG. 10, when the U-shaped iron core 1, the bobbin 4 and the belt-like sheet 16 are assembled, the L-shaped bent portion 17A of the belt-like sheet 16 is sandwiched between the U-shaped iron core 1 and the belt-like sheet 16 Is fixed naturally without any pasting work. Furthermore, since the belt-like sheet 16 exists inside the bobbin 4 whose inner shape is cylindrical, even when the L-shaped bent portion 17 A of the belt-like sheet 16 deviates from the abutting portion of the U-shaped iron core 1, The sheet 16 will not come off the butted part of the U-shaped iron core 1.

[0053] Further, as shown in FIG. 11, when the U-shaped iron core 1, the bobbin 4 and the belt-like sheet 16 are erected, the unbent portion 17B of the belt-like sheet 16 protrudes outside the bobbin 4. It becomes the structure. With this structure, the bobbin 4 force When the external mechanical force is applied to the coil terminal 5 exposed to the outside, there is a possibility that the coil terminal 5 and the U-shaped core 1 may come into contact with each other. Sheet 16 can electrically insulate between coil terminal 5 and U-shaped iron core 1

[0054] Further, as shown in FIG. 11, the presence of the belt-like sheet 16 that protrudes outside the bobbin 4 makes it possible to visually determine whether or not the gap of the belt-like sheet 16 is inserted when the transformer is incorporated into the product. Can be confirmed.

[0055] As described above, according to the fourth embodiment, as shown in Fig. 10, the belt-like sheet 16 is naturally fixed without performing an attaching operation. Part 17

There is no need to paste the gap A.

[0056] Further, as shown in FIG. 10, since the belt-like sheet 16 is held away from the butted portion of the U-shaped iron core 1, the thickness of the gap that is the L-shaped bent portion 17A of the belt-like sheet 16 Can be kept stable.

Further, as shown in FIG. 11, since the coil terminal 5 and the U-shaped iron core 1 can be electrically insulated by the belt-like sheet 16, it is possible to constitute a safer transformer by preventing leakage and the like. .

[0058] Further, as shown in FIG. 11, since the structure can visually confirm whether or not the gap of the belt-like sheet 16 is inserted, it is possible to prevent the gap from being forgotten.

[0059] In Embodiment 3 and Embodiment 4 described above, the L-shaped bent portion 17A of the belt-like sheet 16 may be bent into a continuous V-shape. By rubbing like this, If the number of times of bending is changed, gaps with various thicknesses can be formed.

[0060] Further, in Embodiments 1 to 4 described above, a plurality of belt-like sheets 2 or belt-like sheets 16 may be laminated and used. In this way, the gap size can be easily changed by changing the number of stacked layers. Further, the use of the belt-like sheet 2 or the belt-like sheet 16 having different thicknesses can increase the degree of freedom of the gap size to be formed.

[0061] Further, in Embodiments 1 to 4 described above, the iron core as an example of the core has been described. However, the core is not limited to the iron core, and a generally known ferrite core or the like can be used. What has is good.

[0062] Further, in the first to fourth embodiments described above, the description has been given using the transformer which is an example of the electric device, but the electric device is not limited to the transformer, for example, a rear tuttle or the like. It can be applied to a device having a coil. Industrial applicability

[0063] The core and the electric device having the insulating sheet of the present invention can reduce the number of attaching work steps without attaching the gap and prevent the gap from being forgotten. For example, the core and the electric device for incorporating the device Useful as.

Claims

The scope of the claims

[I] A core with at least two partial forces,

A strip-shaped insulating sheet;

A gap formed by sandwiching the bent portion of the insulating sheet between the cores, and the non-folded portion of the insulating sheet includes an insulating sheet configured along the surface of the core.

[2] The core having an insulating sheet according to [1], wherein the insulating sheet has a strip shape bent into a T-shape.

[3] The core having an insulating sheet according to [1], wherein the insulating sheet has a strip shape bent in an L shape.

4. The core having an insulating sheet according to claim 1, wherein the insulating sheet is in the shape of a band bent into at least two opposing L-shapes.

5. The core having an insulating sheet according to claim 1, wherein the bent portion of the insulating sheet is continuously bent.

6. The core having an insulating sheet according to claim 1, wherein the gap is formed by stacking a plurality of the insulating sheets and sandwiching them between the cores.

[7] A core having the insulating sheet according to claim 1,

An electric device including a coil disposed concentrically with respect to the leg of the core, wherein at least a part of the non-bent portion of the insulating sheet extends between the coil and the surface of the core. Configured electrical equipment.

8. The electric machine according to claim 7, wherein the bent portion of the insulating sheet is continuously bent.

9. The electrical device according to claim 7, wherein the gap is formed by laminating a plurality of the insulating sheets and sandwiching them between the cores.

10. The electrical device according to claim 8, wherein the gap is formed by laminating a plurality of the insulating sheets and sandwiching them between the cores.

[II] The electrical device according to claim 7, wherein the entire length of the unfolded portion of the insulating sheet is longer than the length of the coil.

12. The electric device according to claim 7, further comprising a bobbin constituting the coil, wherein an overall length of the non-bent portion of the insulating sheet is longer than a length of the bobbin.

13. The electric device according to claim 7, wherein a non-bent portion of the insulating sheet is disposed at a position where the core and the coil are insulated.