JPH0128647Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a transformer for a switching regulator, and more particularly to an improvement in insulation means between windings in a transformer for a section-wound switching regulator.

<Prior art> Conventionally, in order to obtain dielectric strength between the windings in a transformer for a section-wound switching regulator, there have been two methods: (1) increasing the withstand voltage by thickening the coating of the copper wire of the winding; 2) using insulating tape between the windings, and (3) winding each winding separately on coaxial multiple bobbins with different diameters.

<Problems to be solved by the invention> However, the first method of increasing the thickness of the copper wire coating does not increase the dielectric strength unless the coating is considerably thick, and thickening the coating requires a special wire material, which increases the cost. Moreover, since the wire becomes thick, a bobbin with a large diameter is required, resulting in an increase in size. In addition, in the method of using the second insulating tape, it is difficult to securely wrap the insulating tape at the part that contacts the bobbin collar, so as shown in Fig. 1, the lower layer winding N1 is After section winding the bobbin 1, insulating tape 2 is wrapped around the surface of the bobbin 1, and then when the upper layer winding N2 is section wound, the upper layer winding N2 is lower than the lower layer winding between the collar 3 of the bobbin 1 and the tape 2. The problem was that it fell toward the wire N1, resulting in a drop in dielectric strength.
Furthermore, although the third method of using multiple bobbins provides perfect insulation, the structure is complicated and large due to the multiple bobbin structure, and the distance between the windings is large, resulting in poor coupling. However, there was a problem with the characteristics.

<Means for Solving the Problems> The present invention has been made to eliminate the above-mentioned drawbacks, and the present invention has been made in order to eliminate the above-mentioned drawbacks. Each protrusion is composed of a base and a tip that protrudes radially outward from the base and has a thickness that is at least smaller than the base, and each of these protrusions After winding the lower layer winding, an insulating sheet having a slit-like through hole into which only the tip of the section fits is wound around the bobbin, thereby forming a connection with the upper layer winding wound on the insulating sheet. The present invention provides a section-wound switching regulator transformer that ensures insulation between the lower windings and provides sufficient dielectric strength without deteriorating workability.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to the accompanying drawings.

2 and 3 are a plan view and a sectional view showing an example of a section-wound bobbin used in a transformer for a section-wound switching regulator according to the present invention, and FIG. An example of an insulating sheet is shown below.

As shown in the figure, in the present invention, the bobbin 1
A plurality of ribs 11, 12, 13 of 0 are formed at predetermined intervals in the circumferential direction, in this embodiment, 4
independent radially outward protrusions 11
Consisting of A to 11D, 12A to 12D, and _13A to 13D, each protruding portion _is as shown in FIG. 5 and _FIG .
D ₁ , 13A ₁ to 13D ₁ are both smaller in thickness (length in the axial direction) and length in the circumferential direction than the base;
Therefore, the tip portions 11A ₂ to 11D ₂ , 12 protrude radially outward with the upper surface of the base exposed to the surroundings.
It is composed of A ₂ to 12D ₂ and 13A ₂ to 13D ₂ .
Note that the flange portions 14 at both ends of the bobbin 10
and 15 is the base 11A ₁ of the protrusion inside
11D ₁ , 12A ₁ to 12D ₁ , and 13A ₁ to 13D ₁ are formed to have small diameter portions 14 ₁ and 15 ₁ of approximately the same height, and both edges of the insulating sheet 16 shown in FIG. , is configured to support when wrapped. Each protrusion 11A to 11
D, 12A to 12D, and 13A to 13D, a row of protrusions in the axial direction, for example, 11A, 12A, and 13A are tip portions 11A ₂ , as shown in FIG.
The bases of 12A ₂ and 13A ₂ have notches 17 at both ends in the radial direction so that when the insulating sheet 16 shown in FIG. 4 is wound around the bobbin 10, it fits only into the tip of each protrusion. The edge of the formed slit-like through hole 18 is engaged with this notch 17 and is fixed. In addition, the remaining protrusions, namely 11B to 11D, 12B to 1
2D and 13B to 13D have no notch at the base of the tip, and are therefore formed as shown in FIG. Of course, all the protrusions may be formed as shown in FIG. 5 so that the insulating sheet 16 can be wrapped from any position, or all the protrusions may be formed as shown in FIG. The insulating sheet may be fixed by suitable fixing means.

On the other hand, as described above, the insulating sheet 16 is formed with slit-like through holes 18 having dimensions that allow only the tips of each protrusion to fit into them, one row more than the number of rows of the protrusions, and transparent holes in the rows at both ends. The protrusion 11A, 1 has a hole having a notch 17 for fixing the insulating sheet as shown in FIG.
2A and 13A. That is, as illustrated in FIG. 7, the through holes in the row at one end are first locked and fixed in the notches 17 of the protrusions 11A, 12A, and 13A, and then wound around the bobbin once, and then the holes in the row at the other end are secured. Reopen the through hole to the protrusion 11A, 1
It is engaged and fixed in the notches 17 of 2A and 13A.

It should be noted that the above embodiments are merely illustrative of the present invention, and it goes without saying that various modifications and changes can be made as necessary. For example, the shape and dimensions of the bobbin, the number of collars and protrusions, the shape and dimensions of the protrusions, etc. can be changed as appropriate, and the thickness and radial length of the tip of the protrusion can be changed as appropriate. However, even if the radial length is not reduced, the lower layer winding, including the transition between sections, is completely covered by the insulating sheet, so reducing only the thickness can have the same effect. is obtained.

<Operation and Effects of the Invention> Since the present invention is configured as described above, first, the bobbin 10 shown in FIGS. 2 and 3 is
The lower winding N1 is connected to the base 11A of each protrusion ₁ to 1.
It is wound by section winding to a height of 1D ₁ , 12A ₁ to 12D ₁ , 13A ₁ to 13D ₁ . Of course, the height of the base is preselected to correspond to the number of turns of the lower winding N1. Next, the insulating sheet 16 shown in FIG. 4 is wound around the bobbin as described above. As a result, only the tip of each protrusion protrudes onto the insulating sheet 16 to form a brim. Next, the upper layer winding N is placed on this insulating sheet 16.
Wind 2 with a section winding. In this way, the coil of the section-wound switching regulator transformer is formed. FIG. 8 shows its cross-sectional view. As is clear from the cross-sectional view of FIG. 8, in the present invention, the insulating sheet 16
1A ₁ ~ 11D ₁ , 12A ₁ ~ 12D ₁ , 13A ₁ ~ 13
_D1 is completely supported by the surface of the seat 16, and both axial edges of the seat 16 are connected to the flange portions 14, 15.
It is completely supported by the small diameter portions 14 ₁ , 15 ₁ . That is, only the tip of each protrusion protrudes from the upper part of the insulating sheet 16, and the lower layer winding N
1 is completely covered by the insulating sheet 16. Therefore, the upper layer winding N2 and the lower layer winding N1 wound on the upper part of the insulating sheet 16 can be completely insulated by the insulating sheet 16,
Sufficient dielectric strength can be obtained. In addition, since the insulating sheet 16 only needs to fit the beginning of the winding to the tips of the protrusions in one row, wrap it around once, and then fit the end of the winding to the tips of the protrusions in the first row. Winding work becomes very easy and work efficiency improves. Furthermore, since the insulating sheet 16 is supported by the surface of the base of each protrusion, the insulation is reliable, and the upper layer winding never falls to the lower layer, improving reliability. Furthermore, complete interlayer insulation can be achieved without the need for coaxial multiple bobbin configurations, resulting in many advantages such as miniaturization and good coupling between windings.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the coil part of a conventional section-wound switching regulator transformer.
2 is a plan view showing a bobbin of an embodiment of a transformer for a section-wound switching regulator according to the present invention; FIG. 3 is a sectional view taken along line 3-3 of FIG. 2; The figure is a plan view showing an example of an insulating sheet wound around the bobbin in Figure 2, and
The figure is an enlarged perspective view of one of the protrusions of the bobbin in Fig. 2, Fig. 6 is an enlarged perspective view of another protrusion of the bobbin in Fig. 2, and Fig. 7 is an enlarged perspective view of one of the protrusions of the bobbin in Fig. 2. FIG. 8 is an explanatory diagram illustrating the manner in which the insulating sheet is wound, and FIG. 8 is a sectional view illustrating a state in which a coil is wound around the bobbin of FIG. 2. 10... Bobbin, 11, 12, 13... Bobbin collar, 11A-11D, 12A-12D, 13
A to 13D...Protrusion, 11A ₁ to 11D ₁ , 12
A ₁ to 12D ₁ , 13A ₁ to 13D ₁ ... base of protrusion, 11A ₂ to 11D ₂ , 12A ₂ to 12D ₂ , 13A ₂
~13D ₂ ...Tip of protrusion, 14,15...
Flange portion, 16... Insulating sheet, 17... Cut portion, 18... Through hole in the insulating sheet.

Claims (1)

[Scope of utility model registration request] Each collar of the section winding bobbin is constituted by a plurality of independent protrusions formed to protrude outward in the radial direction at predetermined intervals in the circumferential direction,
Each of the protrusions includes a base and a tip that protrudes radially outward from the base and has a thickness at least smaller than the thickness of the base, and has a through hole into which only the tip of each protrusion fits. The formed insulating sheet is wound around the bobbin so as to cover the lower layer winding wound within the height of the base of the protrusion, and the upper layer winding is wound on the insulating sheet. transformer for the controller.