JPH0356022Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to the improvement of the coil of a transformer that converts voltage or current, particularly the lead-out portion of the end-of-winding wire of a low-voltage coil.

[Conventional technology]

Conventional transformer coils of this type include those shown in FIGS. 3 to 6. Figure 3 is a cross-sectional view of a transformer with a conventional low-voltage coil, and Figure 4 is a cross-sectional view of a transformer with a conventional low-voltage coil.
Fig. 5 is a perspective view of a part of the low voltage coil shown in Fig. 4, and Fig. 6 is a perspective view of a fixing member for the winding end lead wire used in the low voltage coil shown in Fig. 4. It is a diagram.

In the figure, 1 is a winding frame made of a thick insulating plate formed into a cylindrical shape, 2 is a low-voltage coil made of insulated conductor wire wound in an even number of layers around the outer circumference of the winding frame 1, and 3 is made of a material such as plastic film. An insulating layer made of thin insulating paper wound around the outer periphery of the low voltage coil 2, 4 a high voltage coil made of an insulated conductor wound around the outer periphery of the insulating layer 3, 5 connected to the beginning and end of the winding of the high voltage coil 4, respectively. The primary terminal 6 is a jacket resin formed by integrating the winding frame 1, low voltage coil 2, insulating layer 3, high voltage coil 4 and primary terminal 5, impregnated with synthetic resin or cast, and molded, 7 is a U-shaped One of the cores is inserted into the window 1A for incorporating the core, and the other is inserted into the space 6A of the resin jacket 6 and fixed thereto. Reference numeral 8 denotes a mounting foot attached to the bottom surface 6B of the outer covering resin 6.

2A is the winding end lead wire of the low voltage coil 2, 2B is the winding start lead wire, and 2C is a suitable fixing member such as cotton tape used when the low voltage coil 2 is wound in an even number of layers. The member 2C is folded and held between a part of the outermost layer and the previous layer so that the folded part 2D is adjacent to the winding end exit line 2A.
The end-of-winding lead wire 2A is inserted through the folded portion 2D and is tied to the entire low-voltage coil 2 by a thread 2E for fixing the end-of-winding lead wire.

To form the low-voltage coil 2, the winding frame 1 is fitted onto the bobbin of a winding machine, and the winding frame 1 is wound as shown by the arrow in Fig. 5 until the outermost layer has an appropriate number of turns. When wound, the fixing member 2C is placed in a folded state and further wound an appropriate number of turns on top of it. Next, before or after removing the low-voltage coil from the bobbin of the winding machine, the winding end lead wire 2A is inserted into the folded portion 2D of the fixing member 2C.
Thereafter, with the low voltage coil 2 removed from the bobbin, the thread 2E is wound to tightly bind the entire low voltage coil 2. As shown in FIG. 5 by a dashed line, the fixing member 2C
The portion protruding from the low-voltage coil 2 is cut off to an appropriate length (for example, the portion indicated by the dashed-dotted line in FIG. 5).

[Problem that the invention attempts to solve]

Since the conventional transformer coil is constructed as described above, when thin insulating paper is wound around the low voltage coil 2 to form the insulating layer 3, the output wire fixing thread 2E is attached at the end of the winding.
The winding end wire fixing member 2C is placed in close contact between the thin insulating paper of the insulating layer 3 and the low voltage coil 2, so even if it is impregnated with synthetic resin or cast, it will not fix the winding end wire. Thread 2E and end winding wire fixing member 2C
is difficult to impregnate with synthetic resin and voids occur. Furthermore, since the fixing member 2C extends only to the middle part of the low voltage coil 2 in the axial direction, the low voltage coil 2
An axial step is formed on the outer surface of the cylinder, and this step also causes voids. Winding end exit wire fixing thread 2
E and the winding end lead wire fixing member 2C are often made of a material with a high dielectric constant, and electric field concentration tends to occur in voids near such a high dielectric constant material, making it easy to generate partial discharge. When a partial discharge occurs, there are problems such as dielectric breakdown of the insulating layer 3 between the high voltage coil 4 and the low voltage coil 2. Furthermore, since the wire 2E for fixing the lead line requires binding work, the workability is poor and the cost is high.

This idea was devised to eliminate these problems; voids are less likely to occur, and even if voids occur, there will be no dielectric breakdown due to electric field concentration in the voids, and it can be manufactured easily and at low cost. The purpose is to provide a transformer coil.

[Means for solving problems]

In the transformer coil according to this invention, a fixing member for an end-of-winding lead wire, which is held between layers of a low-voltage coil, is extended through the layers to the end of the coil on the opposite side from the end-of-winding lead wire.

[Effect]

In the transformer coil configured as described above, the fixing member for the end-of-winding lead wire extends between the layers that sandwich it, so it does not come out on the surface of the low-voltage coil, and the fixing member Since the interlayers extend from one axial end to the other axial end, there is no axial step on the outer surface of the low voltage coil, and the winding tension of the low voltage coil ensures tightness between the layers. The winding end lead wire is not pulled out from between the layers and loosened even when and after the winding end lead wire is inserted through the folded portion.

[Example of idea]

An example of this invention is shown below in Figures 1 and 2.
The diagram will be explained. FIG. 1 is an axial cross-sectional view of a low-voltage coil according to one embodiment of this invention installed on the bobbin of a winding machine, and FIG. 2 is a perspective view of the low-voltage coil removed from the bobbin. is a low voltage coil, 9A is a winding end lead wire of the low voltage coil 9, and 9B is a winding end lead wire 9 of the low voltage coil 9.
The axial end on the A side, 9C is the axial end on the opposite side,
10 is a bobbin of a winding machine, and 10A is a flange of the bobbin 10. Reference numeral 11 is a winding end wire fixing member corresponding to the conventional winding end wire 2C, and 11A is a folded portion of the winding end wire fixing member, which is located adjacent to the winding end wire 9A. The fixing member 11 extends between the layers of the low voltage coil 9 on which it is held, that is, between the outermost layer and the previous layer in this embodiment, from the axial end 9B on the winding end lead line 9A side to the opposite axial end 9C. It extends to. Thus,
The fixing member 11 extends between the layers that sandwich it,
Since it is not exposed to the outer surface of the low voltage coil 9, voids caused by the fixing member 11 being exposed to the outer surface of the low voltage coil 9 during resin impregnation or casting are eliminated, and the insulating layer 3 and Since there is no high-permittivity material of the fixing member 11 between them, even if voids occur due to other causes, it is difficult for electric field to concentrate on the voids, and partial discharge is less likely to occur, thereby preventing dielectric breakdown of the insulating layer 3. is prevented.

Further, by extending the fixing member 11 from the axial end 9B on the winding end lead line 9A side to the axial end 9C on the opposite side, the above effect is further enhanced. That is, by extending the fixing member 11 in this way, the fixing member 1 is attached to the outer surface of the low voltage coil 9.
1, and voids caused by such a step are eliminated. Furthermore, since the fixing member 11 is held between the layers of the low-voltage coil 9 over a long distance, it is firmly held between the layers by making the most of the winding tension of the outer layer, and fixes the winding end lead wire 9A. Even when the fixing member 11 is inserted into the folded portion 11A of the member 11 and thereafter, the fixing member 11 is not pulled out from between the layers and loosened, and therefore, there is no need for the conventionally required binding with the thread 2E for fixing the lead line. The occurrence of voids caused by the thread 2E being exposed on the outer surface of the low-voltage coil 9 is eliminated, and even if voids occur due to other causes, electric field concentration on the voids is unlikely to occur because the thread 2E is not present. It is. As described above, by extending the fixing member 11 as described above, the effect of preventing the generation of voids and alleviating the concentration of electric field in the voids caused by other causes is promoted. Since the binding work of 2E is not necessary, it is possible to manufacture the transformer coil with good workability and at low cost.

Note that, as in the illustrated embodiment, the folded portion 11A
After inserting it into the folded part 11A in the direction of arrow 12,
When the winding end wire 9A is bent under tension along the folded portion 11A, the winding end wire 9A is firmly held by the folded portion 11A, and springback or loosening of the low voltage coil 9 is more reliably prevented.

Further, in the above embodiment, the fixing member 11 is sandwiched between the outermost layer of the low voltage coil 9 and the previous layer, but there is also a gap between other layers, for example, between the second layer and the third layer counting from the outermost layer. You can also hold it in between. Also, the fixed member 1
1 is not limited to a tape-like material, but may be a string-like material.

Furthermore, if the axial end 9B of the low-voltage coil 9 on the winding end wire side is wound in a tapered manner as in the illustrated embodiment, this end 9B and the flange 1 of the bobbin 10
A space 13 is formed between the low voltage coil 9 and the low voltage coil 9.
The winding end lead wire 9A can be inserted into the folded part 11A of the fixing member 11 by using the space without removing it from the bobbin 10, improving work efficiency. Further, by forming the winding end wire 9A into such a tapered shape, the winding end lead wire 9A can be easily accommodated within the axial range and the radial range of the low voltage coil 9. In order to wind the layer in a tapered manner as described above, the next layer may be wound an appropriate number of turns (for example, one turn to several turns) less than the number of turns of the innermost layer.

[Effect of idea]

As described above, according to this invention, the fixing member for the end-of-winding lead wire is not exposed on the surface of the low-voltage coil by extending between the layers that sandwich it.
Voids are less likely to occur during resin impregnation or casting, and since the high dielectric constant material of the fixing member does not exist between the outermost layer of the low voltage coil and the surrounding insulating layer, the fixing member is placed on the outer surface of the low voltage coil. The occurrence of voids caused by exposure is eliminated, and even if voids occur due to other causes, electric field concentration in the voids is less likely to occur, and partial discharge is less likely to occur, so dielectric breakdown of the insulating layer is prevented. , the reliability and performance of the transformer are improved, and since the fixing member extends from one axial end to the other axial end between the layers sandwiching the fixing member, the fixing member is attached to the outer surface of the low voltage coil. Therefore, no level difference is generated, and voids caused by such a level difference are also eliminated. In addition, the fixing member is firmly held between the layers, and there is no need to bind it with the winding end wire fixing thread as in the conventional method. This eliminates the occurrence of voids caused by the fibers being exposed on the outer surface of the low-voltage coil, and even if voids occur due to other causes, the absence of these threads makes it difficult for the electric field to concentrate in such voids, and the transformer The reliability and performance of the transformer coil are further improved, and furthermore, since the above-mentioned binding work is no longer necessary, it is possible to manufacture the transformer coil with good workability and at low cost.

[Brief explanation of drawings]

Fig. 1 is an axial sectional view showing the low voltage coil according to an embodiment of this invention before it is removed from the bobbin of a winding machine, and Fig. 2 is a perspective view of the low voltage coil shown in Fig. 1 after it is removed from the bobbin. , Figure 3 is a cross-sectional view of a transformer with a conventional low voltage coil, Figure 4 is a cross-sectional view of a transformer with a conventional low voltage coil.
The figure is a perspective view of the low-voltage coil shown in Fig. 3, and Fig. 5 is an axial cross-sectional view of a portion of the low-voltage coil shown in Fig. 4.
6 is a perspective view of a fixing member for the winding end lead wire used in the low voltage coil of FIG. 4. FIG. In the figure, 1 is a winding frame, 3 is an insulating layer, 4 is a high voltage coil, 9 is a low voltage coil, 9A is a winding end lead wire,
9B and 9C are axial ends of the low voltage coil 9, 11 is a winding end wire fixing member, and 11A is a folded portion of the fixing member 11. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A transformer coil in which a low-voltage coil, an insulating layer, and a high-voltage coil are sequentially wound around the outer circumference of a winding frame, and these low-voltage coils, insulating layers, and high-voltage coils are integrally molded with resin, and the low-voltage coil is arranged in an even number of layers. The end-of-winding wire fixing member of the wound low-voltage coil is folded back and held between the layers of the low-voltage coil so that the folded part is adjacent to the end-of-winding wire, and the end-of-winding wire is fixed to the fixing member. It is characterized in that the fixing member is inserted through the folded part of the paper and is fixed, and the fixing member is extended through the interlayers to an axial end on the opposite side from the winding end lead line side between the sandwiched layers. transformer coil.