JPH062653U - Transformer - Google Patents

Abstract

(57) [Summary] [Purpose] To improve productivity and obtain high reliability while ensuring a predetermined insulating property without taping the spacer tape. [Structure] A core mainly composed of a ferromagnetic material,
A transformer in which a primary winding and a secondary winding are wound in layers through a winding frame made of an insulating material. The body portion of the winding frame around which the primary winding and the secondary winding are wound is formed in a step shape in which the winding width increases from the axial center of the core in the outer peripheral direction. As a result, a sufficient creeping distance is ensured between the opposite ends of the adjacent windings, and high insulation performance is obtained, so the spacer tape is omitted.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a small transformer such as a high frequency transformer used in a switching power supply device, for example.

[0002]

[Prior art]

 Fig. 2 shows a transformer that is used in switching power supplies and has a relatively small capacity and is mounted on a printed circuit board. FIG. 2 is a cross-sectional view of a conventional high frequency transformer (transformer), in which lead wires of each winding and pin terminals to be mounted on a printed circuit board are omitted. In FIG. 2, reference numeral 1 is a core made of an electromagnetic steel plate or the like, 2 is a winding frame fitted in the core 1, and 41 to 43 are windings wound around the winding frame 2.

In the winding frame 2, the body portion 21 and the collar portion 29 form an annular groove 28. The primary winding 42 is wound in layers in the annular groove 28 along the body portion 21, and the secondary winding 41 is wound in layers on the outer peripheral side thereof via an interlayer insulator (tape) 31. ing. Further, a primary winding 43 is wound in layers on the outer peripheral side thereof with an interlayer insulating material (tape) 32 interposed therebetween. An insulating cover member (tape) 33 is attached to the outermost peripheral portion of the primary winding 43.

In such a conventional transformer, it is necessary to secure a creepage insulation distance between the primary windings 42 and 43 and the secondary winding 41, and therefore, between both ends of each winding and the collar portion 29. Are provided with insulating inclusions (spacer tapes) 51 to 53 each having a width of about 2 mm to 3.5 mm.

[0005]

[Problems to be solved by the device]

 If these spacer tapes 51 to 53 are not mounted in order and with high precision between both ends of each winding and the collar portion 29, not only the insulation cannot be secured, but also the reshaped dimensions of the windings are significantly varied. This may result in deterioration of quality. However, the taping process of this spacer tape is complicated in the winding work, and has various points to be solved in order to ensure the quality and cope with various transformers in order to automate and save labor. .

The present invention has been made in view of the above problems existing in the prior art. The problem is that a predetermined insulating property is obtained without performing the taping process of the spacer tape. It is to provide a highly reliable transformer with stable quality and high productivity while ensuring the productivity.

[0007]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the transformer of the present invention has a core mainly composed of a ferromagnetic material, and a primary winding and a secondary winding formed in layers through a winding frame formed of an insulating material. In the wound-up transformer, the body portion of the winding frame, around which the primary winding and the secondary winding are wound, has a staircase in which the winding width increases from the axial center of the core in the outer peripheral direction. It is supposed to be formed into a shape.

[0008]

[Action]

 Since the body portion is formed in a stepped shape, a sufficient creeping distance is secured between the opposite ends of the adjacent windings, so that high insulation is obtained. Therefore, not only is the spacer tape unnecessary, but the taping process can be omitted.

[0009]

【Example】

 An embodiment of the transformer according to the present invention will be described with reference to FIG. FIG. 1 shows a cross-sectional view of a transformer used in a switching power supply device, for example. This embodiment is a high frequency transformer having a comparatively small capacity as used in the conventional example of FIG. 2, and in the drawing, the same parts / members that overlap are given the same numbers. . Similar to FIG. 2, the lead wires and pin terminals of the primary and secondary windings are omitted.

A ferromagnetic material such as an electromagnetic steel plate or a ferromagnetic ferrite is used for the core 1, and thin core plates of about 0.3 mm to 1 mm are laminated to a predetermined thickness or molded into a block shape. The ferromagnetic ferrite is formed in the shape of a square rod. The winding frame 2 is fitted into the hole 27 of the core 1 according to the outer shape of the core 1. The reel 2 is molded using an insulating resin material such as phenol resin. The winding frame 2 has flanges 29, 29 at both ends in the axial direction of the core 1, and primary and secondary windings are wound inside thereof, that is, in the outer peripheral direction of the shaft core. An annular groove 28 is formed.

The annular groove 28 is open because the first body portion 21 to the third body portion 23 and the first collar portion 24 to the third collar portion 26 of the winding frame 2 have a stepped stepped structure. A groove is formed in which the ends are successively larger. In the annular groove 28, firstly, the primary winding 42 is wound around the outer periphery of the first body portion 21 in layers according to the core axis direction of the first body portion 21. (In FIG. 1, the winding is sequentially wound in a spiral shape from the left end of the first body portion 21 to the right direction and from the upper side to the lower side.) That is, the primary winding 42 is formed in the annular groove 28. It is housed in an annular area defined by the first body portion 21 and the first collar portion 24. An interlayer insulating material (tape) 31 made of a material such as polyester is wound and mounted a predetermined number of times so as to cover the outer periphery of the primary winding 42 and the second body portion 22, and the secondary winding 41 is wound next. It serves as an insulating coating for keeping the insulation with.

The secondary winding 41 is wound around the outer circumference of the primary winding 42 with the interlayer insulator (tape) 31 interposed therebetween. The secondary winding 41 is sequentially wound in layers in an annular region defined by the outer peripheral portion of the interlayer insulator (tape) 31 and the second body portion 22 and the second flange portion 25 in the annular groove 28. It is stored. Since the winding width of the second body portion 22 is larger than that of the primary winding 42, the secondary winding 41 can be wound with a relatively large number of turns. An interlayer insulating material (tape) 32 made of a material such as polyester is wound a predetermined number of times so as to cover the outer periphery of the secondary winding 41 and the third body portion 23, like the interlayer insulating material (tape) 31. Insulation covered.

Further, the primary winding 43, which is also divided from the primary winding 42, is wound around the outer periphery of the secondary winding 41 via an interlayer insulating material (tape) 32. The primary winding 43 is successively wound in layers in the annular region defined by the outer peripheral portion of the interlayer insulator (tape) 32, the third body portion 23 and the third flange portion 26 in the annular groove 28, and is housed. To be done. Then, the outermost periphery thereof is wound a predetermined number of times with an insulating cover member (tape) 33 to maintain the insulation with the outside of the transformer. In this way, the primary winding 42, the secondary winding 41, and the primary winding 43 are sequentially arranged from the axis of the core 1 toward the outer periphery, and the primary windings 42 and 43 are divided. This is because the electromagnetic coupling through the core 1 is more effectively maintained, and the loss of leakage magnetic flux can be suppressed as much as possible. Depending on the specifications of the transformer, the primary winding 42 and the secondary winding 41 may be arranged in this order from the axial center of the core 1 toward the outer periphery in the order of two, or in the reverse order of the combination. Needless to say, these windings may be appropriately divided and arranged.

In FIG. 1, the creepage distance between the primary winding 42 and the secondary winding 41 adjacent to the primary winding 42 is secured in the second body portion 22. Similarly, the creepage distance between the primary winding 43 and the secondary winding 41 is secured by the third body portion 23.

As described above, since the second body portion 22 has a stepped shape in which the winding width for accommodating the winding is larger than that of the first body portion 21, the second body portion 22 itself is the primary winding. Corresponding to the creepage distance between the secondary winding 42 and the secondary winding 41, insulation is secured. As a result, the conventional spacer tape can be omitted. Further, with respect to each of the secondary winding 41 and the primary winding 43 arranged on the outer periphery of the secondary winding 41, the insulation is secured at both ends by the creepage distance formed by the third body portion 23. Thereby, the spacer tape can be omitted.

In the transformer of the present embodiment, the spacer tape is omitted, which is convenient for automation of winding. In particular, since the winding width dimensions of the second body portion 22 to the third body portion 23 are specified in advance, it is only necessary to set the winding start position and the winding end position of the winding machine. This has the advantage that a series of automation is not hindered by the taping process of the spacer tape.

Although one embodiment of the transformer according to the present invention has been described above, the present invention is not limited to this, and design changes and modifications can be freely made. For example, in the transformer shown in this embodiment, the core 1 has been described as having a square shape, but the combination of the E-shaped core 1 and the I-shaped core, or the two sets of E-shaped cores. It may be implemented by a configuration such as a combination which is obvious to those skilled in the art. Further, the material is not limited to this as long as it is a ferromagnetic material such as amorphous other than those shown in the examples. The reel 2 is not particularly specified as long as it is an insulating material, but polyamide nylon or phenol resin is preferable in consideration of moldability (glass fiber contained).

Although the number of steps of the staircase shape of the body portion of the winding frame 2 is three in this embodiment (the second body portion 22 to the third body portion 23), the number of windings mounted and the winding divisions It may be set freely according to the number. Needless to say, the staircase shape itself formed by the body portion and the collar portion may be arbitrarily set. Further, the winding method for winding the body of each winding may be double or triple for one winding as long as it is wound in layers.

[0019]

【effect】

 In the transformer of the present invention, since the body portion of the winding frame 2 is formed in a stepped shape, both ends of each winding wound in layers contact each other with different winding widths. In addition, due to the stepped shape of the body portion, a creeping distance facing each other between adjacent windings is secured (in the present embodiment, the second body portion 22 to the third body portion 23). Therefore, not only the spacer tape is unnecessary and the taping process can be omitted, but also the number of parts is reduced, the production cost can be reduced, and the winding process can be easily automated. Then, it is possible to obtain a reliable transformer with stable quality while achieving a predetermined insulation.

[Brief description of drawings]

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

FIG. 2 is a sectional view showing a conventional transformer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 core 2 reel 21 first body part 22 second body part 23 third body part 24 first flange part 25 second flange part 26 third flange part 28 annular groove 29 flange part 31 interlayer insulator (tape) 32 interlayer Insulator (tape) 33 Insulation cover member (tape) 41 Secondary winding 42 Primary winding 43 Primary winding

Claims (1)

[Scope of utility model registration request] 1. A transformer comprising a core mainly composed of a ferromagnetic material, and a primary winding and a secondary winding wound in layers through a winding frame made of an insulating material, wherein: The body portion of the winding frame around which the primary winding and the secondary winding are wound is formed in a stepped shape in which the winding width increases from the axial center of the core in the outer peripheral direction. A transformer.