JPH04209510A - Transformer - Google Patents

Abstract

PURPOSE:To make the title transformer small-sized and thin so as to be suitable for a surface-mounting operation and to easily perform an assembly operation and an operation after it by a method wherein a winding operation is performed on a large-sized bobbin, a medium-sized bobbin and a small-sized bobbin, the three bobbins are assembled and outgoing wires are arranged at insulating tape parts. CONSTITUTION:A bobbin to be used is constituted of a medium-sized bobbin B2, a small-sized bobbin B3 and a large-sized bobbin B1. When fitting parts at the bobbins B1, B2, B3 are fitted, a lower guard 3a at the bobbin B1 and a lower guard 3c at the bobbin B3 come into contact with a lower guard 3b at the bobbin B2 and with a receiver guard 7. At the same time, upper guards 2a, 2b, 2c at the individual bobbins B1, B2, B3 are made flush with each other and the bobbins can be assembled coaxially. Consequently, it is possible to reduce a space required for the creeping distance between the individual outgoing wires and individual windings. When the outgoing wires 15, 16, 17 are arranged at insulating tapes 10a, 10b, 10c, it is possible to surely and sufficiently ensure the creeping distance between the adjacent windings and the creeping distance between the windings and the outgoing wires. Thereby, a transformer which is small-sized and thin so as to be suitable for a surface-mounting operation is obtained. Its assembly property is made good and its cost can be lowered.

Description

[Detailed description of the invention]

[00011

[Industrial Application Field] This invention relates to a transformer. [0002] [0002] FIG. 12 shows a bobbin B used in a conventional surface-mount transformer, in which 21 is a cylindrical portion, 22
and 23 are upper and lower ribs provided at the upper and lower ends of the cylindrical portion 21, respectively; 24 is a terminal block provided on the lower rib 23;
5 is a terminal for surface mounting provided on the terminal block 24. [0003] Since the conventional transformer bobbin B has such a configuration, a coil is wound thereon in the following manner. That is, for example, in the case of double winding, as shown in FIG.
, then a second winding 28 is applied thereto, and an insulating tape 29 is further wound thereon. [0004] In the case where the winding is triple-wound, an insulating tape is further wound on the second winding 28, a third winding is applied on top of the second winding, and an insulating tape is further placed on top of the third winding. It's wrapped. A tube 32 is placed over the lead wire 31 from the coil wound inside. [0005] A conventional transformer is constructed by attaching a pair of bot cores 30 and 30 shown in FIG. 14 from above and below to a bobbin B on which a coil has been wound as described above and whose terminals have been connected. There is. Both cores 30.30 have a slug portion 30a and an outer shell portion 30b, and are mounted on the bobbin B by inserting the respective slug portions 30a into the cylindrical portion 21 of the bobbin B from above and below. [0006]

[Problems to be Solved by the Invention] Conventional bobbins B, especially those with three windings, have a structure in which the three windings are insulated with insulating tape, so that a high dielectric strength voltage is required between the three windings. In order to ensure creepage distance or space distance between the three windings in accordance with the standard voltage, it is necessary to make the bobbin larger in the plane direction and wrap the insulating tape thickly. For this reason, it has not been possible to obtain a small and thin transformer required for single-sided mounting. Also,
In order to ensure high dielectric strength between the lead wire and the winding, it was necessary to cover the lead wire with a tube or to ensure a creepage distance or clearance that complied with the standards. Furthermore, if the insulating tape shifts in the vertical direction of the bobbin B due to variations in the winding process of the insulating tape, the required creepage distance may not be secured. [0007] This invention was made in order to solve the above-mentioned problems, and can sufficiently and reliably secure the required creepage distance. The objective is to obtain a transformer that is easy to assemble and perform subsequent work. [0008]

[Means for Solving the Problems] A transformer according to the present invention has a shape in which upper and lower ribs are provided at the upper and lower ends of a cylindrical part, respectively, and which are coaxially arranged by fitting the fitting parts together. The transformer is constructed by winding wires on three large, medium, and small bobbins that are assembled one on top of the other, and the winding has a structure in which the portion through which the lead wire passes is covered with an insulating tape. [0009]

[Operation] In this invention, when three bobbins (large, medium, and small) are wound and assembled, the creepage distance between adjacent windings is determined by the width of the upper rib of the bobbin interposed between both windings. A distance equal to twice the thickness can be secured. Therefore, the space required to take creepage distance between each winding can be reduced. Further, in the present invention, when the lead wire is arranged in the insulating tape portion, a distance up to twice the bobbin winding width can be secured as the creepage distance between the lead wire and the winding wire. Therefore, the space required to take the creepage distance between the lead wire and the winding wire can be reduced. [0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 8. [0011] The bobbin used in the transformer of the example is:
It is composed of three bobbins: a medium bobbin B2 shown in FIGS. 2 and 5, a small bobbin B3 shown in FIG. 3, and a large bobbin B1 shown in FIG. 4. These three bobbins Br, B2,
When B3 is fitted with the fitting portions described later, as shown in FIG.
and each bobbin B+, B2, B
The upper ribs 2a, 2b, 2c of 3 are flush with each other so that they can be assembled coaxially. [0012] Large, medium, and small bobbins B+, B2,
In B3, la, lb, lc are cylindrical parts, 2a,
2b and 2c are the upper ribs provided at the upper ends of the cylindrical parts 1a, lb, and lc, respectively; 3a, 3b, and 3c are the lower ribs provided at the lower ends of the cylindrical parts 1a, lb, and IC, respectively; 4a, 4b, and 4c. Upper brim 2a, 2b,
2c are lead line guides provided respectively. In the large and medium bobbins B+ and B2, 10a and 10b are insulating tapes with one end attached to the lead wire guides 4a and 4b side of the cylindrical portions 1a and lb, and the other end drawn out to the outside of the bobbin. In middle bobbin B2, 5 is lower brim 3
A terminal block is provided integrally with b, and 6 is a piece provided with the terminal block 5.
This is for attaching surface mount terminals. 7.7
ml is a pair of receiving collars provided on the inner circumferential surface of the lower end of the cylindrical portion 1b, and ml is a fitting groove formed between the receiving boxpieces 7, 7. The above-mentioned rib holder 7.7 is a collar for placing the lower collar 3c of the small potbin BJ, and the fitting groove m1 is the small potbin B.]
This is a groove for fitting a fitting piece 8 (described later). m2
is a fitting groove formed between the upper flange 2b and the lead wire guides 4b, 4b. When a fitting piece 9 (described later) provided on the upper collar 2a of the large pobbin B1 is fitted into this groove m2, rotation of the large pobbin B1 is prevented. In the small water bottle B3, 8, 8 is a fitting piece provided on the lower flange 3c and protrudes downward.
3 rotation is prevented. In large pobin B1, 9.
9 is a fitting piece provided on the upper flange 2a. When these fitting pieces 9, 9 are fitted into the fitting groove m2 of the medium bobbin B2, rotation of the large bobbin B1 is prevented. [0013] Since the transformer pobbin of the embodiment is composed of the above-mentioned three bobbins B+, B2, and B3, when making a transformer using this bobbin, for example, it is assembled in the first step. (1) Piece 6 of middle bobbin B2
Attach the terminal 14 for surface mounting (Fig. 1) to the terminal. (2
) As shown in Figures 6 to 8, each large, medium, and small bobbin B+,
Windings 11, 12 and 13 are applied to B2 and B3, respectively. At this time, the winding 11 applied to the bobbin Bl, B2
．． 12 is a bobbin Bt of the insulating tapes 10a, 10b which are wound around the cylindrical parts 1a, 1b from above the insulating tapes 10a, 10b pasted on the respective cylindrical parts 1a, 1b, and after winding is completed,
The part protruding from B2 is folded back onto the winding 11.12 and placed between the collars 2a and 3a of the bobbin B1 and the collars 2b and 3b of the bobbin B2. 17 is a lead wire of the winding 11, 16 is a lead wire of the winding 12, and 15 is a lead wire of the winding 11. (3) Small potbin B3 to medium potbin B
2 into the cylindrical part 1b, and insert the fitting piece 8 of the small pot B3.
, 8 into the fitting groove mr of the medium pot bin B2, and then insert the small pot bin B.
Place the lower flange 3c of 3 on the receiving flange 7, 7 of the middle pot bin B2. (4) Fit the large bobbin B1 into the middle bobbin B2, and fit the fitting pieces 9, 9 of the same bobbin B+ into the fitting groove m2 of the middle bobbin B2. (5) Winding 11. 12. 13 lead wires 17, 16, and 15 are connected to the terminal 14, and a bot core having the same shape as shown in FIG. 14 is attached. FIG. 1 shows a cross section of the assembled state of three bobbins B1 to B3 obtained as described above, in which 14 is the above-mentioned terminal, 11, 12, 13 are windings, and 10a, 10b are It is an insulating tape and wraps part of the windings 11, 12. [0014a] Next, the operation will be explained. When the three bobbins B+-83 of the embodiment are assembled with windings 11 to 13 applied to each, as shown in FIG. 8, the windings 11 and 12 are separated by the cylindrical portion 1a of the large bobbin B+, 12 and 13
are partitioned by the cylindrical portion 1b of the middle bin B2. and,
The creepage distance between the windings 1 and 12 is the width of the upper rib 2a of the large pobin B1 plus twice the thickness, and is sufficiently secured. Also, the creepage distance between windings 12 and 13 is
The distance is the width of the upper brim 2b of the middle pot bin B2 plus twice the thickness, which is sufficiently secured. In addition, the creepage distance between the lead wire 15 and the winding 12 and between the lead wire 16 and the winding 11 is determined by the thickness of the upper ribs 2a, 2b and the thickness of the insulating tape 10a.
, 10b are secured in addition to the portions covering the windings 11 and 12, and the covering portion is secured up to the winding width of the bobbin (between the upper and lower ribs). For this reason, each winding 11~
13 can be reduced, and there is no need to cover the lead wires 15 and 16 with tubes, which allows the transformer to be made smaller and thinner. [0015] In the above embodiment, one end of the insulating tape was folded back and placed over the winding, but as shown in FIG. Winding 10 when pulled out from bobbin B1
After completing the winding, as shown in Figure 10, insulating tape 40
Both ends of a may be folded back over the winding 11 and placed over the same winding 11. Do the same for bobbin B2. In this way, as shown in FIG. 11, the creepage distances between the lead wire 15 and the winding 12 and between the lead wire 16 and the winding 11 are more sufficient than in the above embodiment in which one end is folded back. Secured. In addition, although a bot core is shown as the core in the example, the shape of the core can be E if it has a triple bobbin configuration.
I cocoa or EEC core may be used. [0016]

[Effects of the Invention] As described above, according to the present invention, large effects can be achieved. Assembled by winding three bobbins (medium and small), and covering the part of the winding through which the lead wire passes with insulating tape, the creepage distance between adjacent windings and the distance between the winding and the lead wire are A sufficient creepage distance can be ensured and, therefore, a small and thin transformer suitable for surface mounting can be obtained. Further, since tubes and the like are not required, assembly is easy, and a small and inexpensive transformer can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a coil portion of a transformer according to an embodiment of the present invention.

[Fig. 2] A perspective view showing a state in which insulating tape is attached to the middle bobbin used in the transformer of the example.

[Figure 3] Perspective view of a small pobbin used in the transformer of the example

[Fig. 4] A perspective view showing a state in which insulating tape is attached to a large pot bin used in the transformer of the example.

[Figure 5] Plan view of Figure 2

[Fig. 6] A perspective view showing the state in which the bobbin shown in Fig. 2 is wound.

[Fig. 7] A perspective view showing a state in which the bobbin shown in Fig. 3 is wound.

[Fig. 8] A perspective view showing a state in which the bobbin shown in Fig. 4 is wound.

FIG. 9 is a perspective view showing an insulating tape attached to a bobbin in another embodiment.

FIG. 10 is a perspective view showing the state in which the bobbin shown in FIG. 9 is wound;

[Fig. 11] A cross-sectional view showing a coil incorporating the bobbin of Fig. 10.

[Fig. 12] Perspective view of a conventional transformer bobbin

[Figure 13]
A sectional view showing the bobbin shown in Figure 12 in a state where the wire is wound and assembled.

[Figure 14] A perspective view of the pot core attached to the bobbin in Figure 13.

[Explanation of symbols]

B+ Large bobbin B2 Medium bobbin B3 Small bobbin la, lb, lc Cylindrical portion 2a, 2b, 2c Upper collar 3a, 3b, 3c Lower collar 10a, 10b, 40b Insulating tape 11, 12.
13 winding 15, 16. 17 Lead line In the drawings, the same reference numerals indicate the same or corresponding parts.

[Figure 11]

Claims (1)

[Claims] Claim 1: A tube having a shape in which an upper and a lower rib are provided at the upper and lower ends of the cylindrical part, respectively, and three large, medium, and small parts that are coaxially stacked and assembled by fitting the fitting parts. 1. A transformer constructed by winding a bobbin, wherein a portion of the winding through which a lead wire passes is covered with an insulating tape.