JPH0442514A - Insulating method for toroidal core and insulating sheet thereof - Google Patents

Abstract

PURPOSE:To apply an automatic device to insulate the surface of a core by deviating a plurality of punched insulating sheets on a toroidal core, superposing thereon, and adhering it. CONSTITUTION:A punched insulating sheet 2 has an annular part 3 corresponding to the end face of a core 1, a tongue piece 4 of its inner peripheral side, and a tongue piece 5 of its outer peripheral side. A small hole is opened at the center of the piece 4, a cutting seam is formed radially, and the piece 5 is radially extended from the outer periphery. One sheet 2 is adhered to the inner and outer peripheral sides by adhering the part 3 to the upper end face of the core 1 and pressing the pieces 4, 5 down. Then, when two sheets 2 are similarly adhered from below the core 1, the ends of the pieces 4a and 5a are respectively superposed to each other.

Description

Detailed Description of the Invention A. Object of the Invention [Field of Industrial Application] The present invention relates to a toroidal core insulating method used in a noise prevention choke coil for suppressing electromagnetic noise by mounting it on an electronic device, and Regarding the insulation sheet.

[Conventional technology]

A toroidal core (hereinafter abbreviated as core) made of powder magnetic material or ferrite material is usually housed in a core insulating case, which is an insulating resin molded product, and is inserted through the center hole of the core from above the insulating case. windings are applied to make it into a choke coil.

Core insulation cases include those consisting of a bottomed double cylindrical case body and an annular lid plate, and those consisting of a bottomed double cylindrical case body divided into two equal parts.
The core insulating case is made in large quantities using a resin mold.

[Problem to be solved by the invention]

The core insulating case is extremely expensive when the number of units manufactured is small, as the depreciation cost of the resin molding mold is relatively high, and the number of units produced for choke coils that use a large toroidal core is small, so an insulating case is used. This rarely happens, and high withstand voltage characteristics are required, so the core is insulated by wrapping an insulating tape that can reliably insulate the entire surface of the core, so-called taping. This work called taping is a manual process, which has the drawbacks of low efficiency and the need for skilled workers.

Structure of the Invention [Means for Solving the Problems] An object of the present invention is to use an automated device to insulate the surface of a toroidal core in a noise prevention choke coil that uses a large core that is manufactured in small numbers. The object of the present invention is to provide a novel insulating method for toroidal cores that can be applied, and is characterized in that the core is insulated by pasting a plurality of punched insulating sheets of the same shape.

The present invention relates to a toroidal core having an annular or angular shape, and is provided with tongue-shaped punched insulating sheets that extend radially from the upper and lower surfaces of the annular portion and from the inner and outer circumferential sides of the core. It is characterized by

Further, the present invention is characterized in that a punched insulating sheet is attached to the toroidal core, which consists of a band-shaped portion corresponding to the outer peripheral surface of the core and band-shaped tongue pieces regularly provided on both sides of the band-shaped portion.

That is, the present invention provides: 1. A method for insulating a toroidal core, which comprises: attaching a plurality of punched insulating sheets to the surface of a toroidal core in a staggered manner to electrically insulate the surface of the toroidal core.

2. A tongue piece with a tapered tip is provided on the inner circumferential side and outer circumferential side of the annular part corresponding to the upper and lower end surfaces of the toroidal core, and an adhesive is attached to at least one side of the annular part and the tapered tongue piece. insulation sheet.

3. A belt-like part corresponding to the outer circumferential surface of the toroidal core and a belt-like tongue piece are provided on both sides of the belt-like part, and an adhesive is attached to at least one side of the belt-like part and the belt-like tongue piece. It is an insulating sheet.

[Effect]

By pasting the punched insulating sheets over and overlapping the surface of the toroidal core, the sheets completely cover the surface of the toroidal core and completely electrically insulate the core and the windings.

The annular portions of the punched insulating sheet that correspond to the upper and lower surfaces of the toroidal core and the band portions that correspond to the side surfaces of the toroidal core cover the end surfaces and outer peripheral surface of the toroidal core, respectively, and the tongue pieces cover the inner and outer peripheral surfaces of the toroidal core. Partially covers the surface, end surface, and inner circumferential surface.

〔Example〕

A first embodiment of the present invention will be described with reference to FIGS. 1 to 4.

Fig. 1 is an external perspective view of the toroidal core 1 after insulation, and Fig. 2 is a plan view of the punched insulating sheet (hereinafter simply referred to as the sheet) 2 used, which is a polyester film with an adhesive attached to one side. .

Or made of glass cloth, etc.

As shown in FIG. 2, the sheet 2 consists of an annular portion 3 corresponding to the end surface of the core 1, a tongue piece 4 on the inner peripheral side of the annular portion 3, and a tongue piece 5 on the outer peripheral side, and one side is coated with an adhesive. It is coated. The tongue piece 4 is formed by making a small hole in the center of the central circular part of the annular part 3, making cuts in the radial direction, and dividing the inner peripheral side into eight equal parts in this embodiment. The tongue pieces 5 have a similar shape to the tongue pieces 4 and extend radially from the outer circumference of the annular portion 3. The height dimension of the tongue piece 5 is almost the same as the height of the tongue piece 3. The dashed-dotted line indicated by S indicates the reference line of the sheet 2.

FIG. 3 shows a state in which the two sheets 2 of the first layer are attached to the core 1 from above and below with the reference line oriented as indicated by the dashed line S. First, the annular portion 3 of the first sheet 2 is attached to the upper end surface of the core 1, and the tongues 4 and 5 are pressed down to attach the first sheet 2 to the inner and outer circumferential sides of the core 1, respectively. Next, when the second sheet 2 is similarly attached from below the core 1, the tips of the tongues 4a and the tongues 5a overlap as shown by broken lines. The inner and outer peripheries of the core 1 are partially covered with the tongues 4a and 5a of the first layer sheet 2, respectively, and the core surface is formed at regular intervals in a diamond-shaped part A whose diagonal length is the same as the height of the core 1. will remain.

FIG. 4 shows the two sheets 2 of the second layer shifted from the position shown in FIG. (Rotation) The state shown is that it is pasted in the same way on top of the first layer. In the figure, the dashed line is 2
First layer tongue piece 4a hidden by layer tongue pieces 4b and 5b
, 5a are shown. On the inner layer and outer core surface of the core 1, only small diamond shapes B remain at regular intervals. This core surface B
is covered with three layers of sheets 2 to complete the insulation of the core 1 as shown in FIG.

In the case of the sheet 2 shown in FIG. 2, in principle it can be applied to a core whose height is such that the tips of the tongues 4 overlap.

However, in practical terms, 6 to 10 sheets are stacked and pasted in 3 to 5 layers in a staggered manner.

5 and 6 show a second embodiment of the invention.

FIG. 5 is an external view of the insulation completed state.

FIG. 6 is a perspective view showing a state in the middle of the insulation process.

The toroidal core 6 has an inner diameter and a height that are approximately the same. As shown partially unfolded in FIG. 6, the sheet 7 includes a band-shaped portion 8 that has a width that is approximately the same as the height of the core 6 and is slightly longer than the entire outer circumference of the core 6, and its side edges (
It consists of a band-shaped tongue piece 9 and a tongue piece 10 that are continuously provided facing each other (upper and lower in the figure), and one side of the sheet 7 is coated with an adhesive. The belt-shaped tongue piece 9 and the tongue piece 10 are the core 6
It has a shape in which a rectangular part is connected to the short side of a trapezoidal part corresponding to the fan shape of the end face, and the total length of the rectangle of both band-shaped tongue pieces 9 and tongue pieces 10 is slightly larger than the height dimension of the core 6. It is set as follows.

In FIG. 6, the second layer sheet 7 is attached to the core 6, which covers almost the entire surface by pasting the first layer sheet 7, and the second layer sheet 7 is attached to the tongue piece 9 and the tongue piece 10.
The number indicates the state in which the root is pasted with a shift of approximately half the width of the root.

One end (left end) of the belt-shaped portion 8 of the sheet 7 is connected to a tongue piece 9 and a tongue piece 10.
The second and third sheets are pasted on the outer peripheral surface of the core 6. Next, the first tongue piece 9 is tilted toward the inner circumferential side and the trapezoidal part is attached to the end surface (lower side) of the core 6. The long rectangular part of the tongue piece 9 is inserted into the central hole of the core 6 and is in the state again. This rectangular part is the core 6
It is bent along the inner circumferential edge of the core 6 and attached to the inner circumferential surface thereof in parallel to the axial direction of the core 6. Next, the first tongue piece 10 is similarly attached to the end surface (upper side) of the core 6, the rectangular part is attached to the inner peripheral surface, and the first tongue piece 10 is overlapped with the tip of the tongue piece 9.

Figure 6 shows how to proceed with this procedure until the fourth tongue piece 9.
, the pasting of the tongue piece 10 and the fifth and sixth tongue pieces 9 is finished, the fifth tongue piece 10 is pasted on the end face of the core 6, and the state is just before pushing down its rectangular part toward the inner peripheral surface. It shows.

The other end (right end) of the band-shaped portion 8 of the sheet 7 is pasted with one end (left end) slightly overlapping as shown in FIG. The 13th tongue piece 9.10 (not shown) is the 1st tongue piece 9.10
Similarly, there is some overlap. The tongue pieces 9 of the first layer sheet 7,
The boundary between the tongues 10 is covered with the second layer of tongues 9 and 10, so that the entire surface of the core 6 can be electrically insulated. It is also possible to attach the band 8 to the entire outer periphery and surface of the core 6, make the band-shaped tongues 9 and 10 into a crown shape, and then sequentially fold and attach them.

In the case of the sheet 7, by appropriately adjusting the shape of the tongue piece to match the shape of the core, the present invention can be applied to cores of any shape.

Effects of the Invention [Effects of the Invention] As explained above, according to the present invention, a punched insulating sheet can be easily made using a punching die that is lower than a resin molding die, and the sheet can be Pasting requires only a simple operation, and has the advantage that automated equipment can be applied.It is effective in electrically insulating toroidal cores more efficiently and at lower cost than before, regardless of whether the number of pieces manufactured is small.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of an insulated toroidal core showing an embodiment of the present invention. FIG. 2 is a plan view of a punched insulating sheet used for the toroidal core of FIG. 1. FIG. 3 is a perspective view showing a state in the middle of insulation according to the present invention. FIG. 4 is a perspective view of an intermediate state of insulation according to the present invention. FIG. 5 is an external perspective view of a toroidal core in a second embodiment of the present invention. FIG. 6 is a perspective view showing a state in which the embodiment of FIG. 5 is in the middle of insulation. 1.6... Toroidal core, 2.7... Punched insulating sheet, 3... Annular part, 4.5.9.10... Tongue piece, buttock... Band-shaped part, 4a, 5a...・1 layer tongue piece, 4b
, 5b... second layer tongue piece, 4c, 5c... third layer tongue piece.

Claims (3)

[Claims] 1. A method of insulating a toroidal core, characterized by electrically insulating the surface of the toroidal core by stacking and pasting a plurality of punched insulating sheets on the surface of the toroidal core. 2. A tongue piece with a tapered tip is provided on the inner circumferential side and outer circumferential side of the annular part corresponding to the upper and lower end surfaces of the toroidal core, and an adhesive is attached to at least one side of the annular part and the tapered tongue piece. Insulating sheet. 3. An insulating sheet comprising: a strip corresponding to the outer circumferential surface of a toroidal core; strip-shaped tongues on both sides of the strip; and an adhesive attached to at least one side of the strip and the strip-shaped tongue. .