JPH0219938Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an improvement of a coil for a molded transformer, which is formed by winding a sheet-like conductor such as an aluminum strip.

[Background technology of the invention]

Generally, coils for molded transformers that use sheet-like conductors such as aluminum strips are as shown in Figure 5.
Interlayer insulator 2 slightly wider than sheet conductor 1
(For example, an interlayer insulator made of a prepreg material impregnated with a thermosetting resin and brought into a semi-cured state) is wound while intervening between the sheet-like conductors 1 to form the bare coil 3, and then The gap between the ends of the interlayer insulator 2 protruding from both end faces of the conductor 1 is filled with a thermosetting synthetic resin containing a filler by dropping or other appropriate means, and together with the resin impregnated into the interlayer insulator 2, The coil 4 for a molded transformer was produced by heating and curing.

[Problems with background technology]

However, the coil 4 for the molded transformer described above
When manufacturing the bare coil 3, the sheet-like conductor 1 and the interlayer insulator 2 are overlapped and wound on the wide interlayer insulator 2 during the winding work.
(In other words, the distance l between both end faces of the sheet-like conductor 1 and the interlayer insulator 2 cannot be kept constant. This is because the sheet-like conductor 1 has a large tension. However, since the interlayer insulator 2 will break if a large tension is applied, it is not possible to apply too much tension. In some cases, the interlayer insulating material 2 is wound unevenly in either direction. In this way, if the interlayer insulator 2 is offset, the insulation properties of the end face of the coil at the offset portion will be significantly weakened, so in this case, the relative positional relationship of the interlayer insulator 2 to the sheet conductor 1 is corrected each time. At the same time, he was working on winding wires. However, when the interlayer insulating material 2 is wound while being corrected, if the correction becomes large, the end portion of the interlayer insulating material 2 near the corrected position may become sagging or wrinkled, as shown in FIG. Something happened. If the aforementioned slack S occurs in the interlayer insulator 2 during winding of the sheet conductor 1, the sheet conductor 1 will be wound with most of the slack S remaining intact. Become.

Therefore, when the synthetic resin is filled from one winding end face of the bare coil 3 after winding the bare coil 3, the resin passes through the bare coil 3 from the slack S portion and is discharged from the opposite winding end face. It leaked and the elementary coil 3
There was a drawback that the molding work on the end face of the winding could not be carried out smoothly. For this reason, one winding end surface of the bare coil 3 is usually placed on a silicone rubber sheet or the like and sealed to prevent the resin from leaking out, making the molding process very time-consuming. It was inefficient.

In addition, when the sheet conductor 1 is cut to a certain width, burrs occur at the cut portion, and when a sheet conductor with burrs is used, the protrusions of the burrs destroy the interlayer insulation, causing the interlayer There was a risk of insulation failure.

[Purpose of invention]

The present invention eliminates the above-mentioned drawbacks, suppresses the sagging that occurs every time the winding position of the interlayer insulator is corrected, and enables smooth filling of resin into the winding end surface of the coil. It is an object of the present invention to provide a coil for a molded transformer that prevents interlayer insulation from being destroyed by burrs generated at cut portions of a sheet-like conductor.

[Summary of the idea]

The coil for a molded transformer of the present invention is produced by applying adhesive insulating tape to both ends of the sheet-like conductor while not covering the end surface of the sheet-like conductor. When winding the sheet-like conductor, the tension of the sheet-like conductor is applied only to both ends of the sheet-like conductor to prevent sag from occurring near the winding end surface of the interlayer insulator, and to prevent burrs from forming on the end surface of the sheet-like conductor. The purpose is to prevent damage to interlayer insulators and improve the reliability of molded transformer coils by using sheet-like conductors.

[Example of idea]

Embodiments of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 3, the same parts as in the conventional example will be described with the same reference numerals. In FIG. 1, an adhesive insulating tape 5 is placed between both ends of the sheet-like conductor 1 and the end of the interlayer insulator 2 protruding from the end surface of the sheet-like conductor 1. Burr a at the cut portion of the width direction end face
(See FIG. 3). As shown in FIG. 2, this insulating tape 5 is attached to both ends of the sheet-like conductor 1 at the same time as the sheet-like conductor 1 is wound. That is, the sheet-like conductor 1
2 is polymerized with the interlayer insulator 2 and wound on the winding frame 6 to form the element coil 3a as in the conventional case. During the winding, the sheet-like conductor 1 is coated with the wires shown in FIG. 2 at both ends. As shown in the figure, a narrow adhesive insulating tape 5 is attached and wound at the same time as the sheet-like conductor 1. Therefore, as shown in FIG.
The interlayer insulator 2 protrudes from the gap between the ends of the interlayer insulator 2 and is attached to both ends of the sheet-like conductor 1 without covering both end faces of the sheet-like conductor 1 . Therefore, during winding of the sheet conductor 1,
If the interlayer insulator 2 is out of position relative to the sheet conductor 1, if the interlayer insulator 2 is gradually corrected to the correct winding position while winding work is performed, the area near the corrected point will be This causes sagging and wrinkles at the ends of the interlayer insulator 2. However, since the sheet-like conductor 1 is wound with a narrow insulating tape 5 attached to both ends thereof, when manufacturing the element coil 3, the tension applied to the sheet-like conductor 1 is applied only to its both ends. (In other words, in the sheet-shaped conductor 1, a space is created between the part of the sheet-shaped conductor 1 and the interlayer insulator 2 where the insulating tape 5 is not present, and no tension is applied to this part when winding the sheet-shaped conductor 1. Even if slack occurs near the ends of the interlayer insulator 2 during winding, as the sheet-like conductor 1 is wound one after another, the tension applied only to the ends of the sheet-like conductor 1 will cause the above-mentioned The slack portion of the interlayer insulator 2 can be gradually crushed and reduced in size. In this way, the sheet-like conductor 1 is polymerized with the interlayer insulator 2, and the insulating tape 5 is attached only to both ends of the sheet-like conductor 1 while being wound to form an elementary coil.
form a. Subsequently, resin is filled between the ends of the interlayer insulator 2 protruding from both end faces of the sheet-like conductor 1 from one end face of the element coil 3. On this occasion,
Since the end face of the elemental coil 3 has almost no slack due to the winding of the interlayer insulator 2, the filled resin does not flow down inside the elemental coil 3a and leak from the opposite end face. After this, the elementary coil 3a
The resin filled in the end face and the resin impregnated into the interlayer insulator 2 are heated and hardened. Once the resin is heated and cured, turn the bare coil 3a over and remove the bare coil 3a.
Similarly to the above, the end face on the opposite side where the resin is not filled is also filled with resin, and this is heated and hardened to form a resin insulating layer 7 on both end faces of the bare coil 3a, thereby forming the molded transformer coil of the present invention. Complete the production of 4a.

Moreover, the molded transformer coil 4a of the present invention is
When winding the sheet-like conductor, an elementary coil 3a is formed by winding the sheet-like conductor 1 on both end faces with insulating tape 5 interposed at positions corresponding to the burrs a of the sheet-like conductor 1. Therefore, as shown in FIG.
Even if this occurs, the burrs a can be prevented from digging into the insulating tape 5 and damaging the interlayer insulating material 2.

Next, the state in which the molded transformer coil 4a constructed as described above is assembled into the iron core 8 is as shown in FIG. In the figure, 9 is a coil holder;
10 is an iron core tightening fitting.

FIG. 4 shows another embodiment of the present invention, in which instead of attaching insulating tape 5 to both ends of the sheet-like conductor 1, the ends of the interlayer insulator 2 are folded back into a narrow tape shape. The present invention can also be achieved by placing the sheet-like conductor 1 on the folded portion 2a and winding it.

[Effect of idea]

As explained above, in the molded transformer coil of the present invention, when winding a sheet-like conductor, a narrow insulating tape or a layer between A tape-like insulator formed by folding back the end of the insulator is interposed between the end of the interlayer insulator wider than the sheet-like conductor, and an elementary coil is wound therein,
Since the resin insulating layer is provided in the gap formed between the ends of the interlayer insulator protruding from both end faces in the axial direction of the element coil, the following effects are achieved.

This invention polymerizes the sheet-like conductor and the wider interlayer insulator by interposing a narrow tape-like insulator from the end face of the sheet-like conductor to the end of the wider interlayer insulator. When winding a bare coil, the tension of the sheet conductor is applied only to both ends of the interlayer insulator in the width direction during the winding (the ends of the interlayer insulator and the sheet conductor are Since the insulator is interposed, there is a space between the center part of the sheet-like conductor and the interlayer insulator, so no tension is applied to this part during winding.)
Since the structure is configured as shown in FIG. can be reliably prevented. In other words, the slack portion of the interlayer insulator that occurs during winding of the sheet-like conductor is removed by effectively utilizing the tension applied to the widthwise ends of the interlayer insulator when winding the sheet-like conductor. The element coil can be made smaller by winding it while adjusting it, and thereby the element coil can be smoothly wound without creating a slack part due to the interlayer insulating material on the end face in the axial direction.

In addition, since the narrow tape-like insulator is pasted on the end face of the sheet-like conductor between the edge of the interlayer insulator in correspondence with the burr of the cut part, it is easy to cut the sheet-like conductor. There is no possibility that the interlayer insulating material is damaged due to burrs in the parts and the insulation deteriorates, and a highly reliable coil for a molded transformer can be obtained.

Furthermore, when filling the gap formed between the interlayer insulators on the end faces of the bare coils with synthetic resin, there is almost no slack in the interlayer insulators on the axial end faces of the bare coils, so the resin filling process is easy. This can be done smoothly and efficiently, and the tape-shaped insulating material attached to the end of the sheet-like conductor is inside the resin insulating layer formed by filling the end face of the elementary coil with synthetic resin. Because it is embedded in the coil, it can be held without falling off the end face of the coil.

In this way, in the present invention, in addition to the interlayer insulating material, a narrow tape-like insulating material is interposed on the axial end surface of the coil in correspondence with the burrs at the cut portion of the sheet-like conductor. It is possible to reliably prevent sagging and damage to the interlayer insulation, and to provide a resin insulation layer by filling the gap between the axial end faces of the coil with synthetic resin, thereby strengthening the insulation of the end faces of the coil. This makes it possible to provide a highly reliable molded transformer coil with improved insulation and productivity.

[Brief explanation of drawings]

Figure 1 is a partially enlarged sectional view showing the molded transformer coil of the present invention assembled into an iron core;
The figure is an explanatory diagram showing the winding state of the transformer coil of the present invention, Figure 3 is an enlarged sectional view of the P section of Figure 1, and Figure 4 is an enlarged sectional view of the main part showing another embodiment of the present invention. , Fig. 5 is a partially enlarged cross-sectional view showing a state in which a conventional transformer coil is assembled into an iron core, and Fig.
It is a sectional view taken along the line AA in the figure. 1... Sheet-like conductor, 2... Interlayer insulator, 3,
3a... Plain coil, 4, 4a... Coil for molded transformer, 5... Insulating tape, 8... Iron core.

Claims (1)

[Scope of utility model registration request] In a transformer coil constructed by overlapping a sheet-like conductor 1 made of aluminum, copper, etc. and an interlayer insulator 2 wider than the sheet-like conductor 1 and winding it a predetermined number of times, the width direction of the sheet-like conductor 1 is At both ends, a tape-shaped insulator with a narrow width and high adhesiveness is protruded from the end face of the sheet conductor 1 at a position corresponding to the burr a on the cut part of the end face of the sheet conductor 1. The sheet-like conductor 1, which is pasted along the length direction and pasted with the tape-like insulating material protruding from the end face in the width direction, is polymerized and wound together with the interlayer insulating material 2 which is wider than the tape-like insulating material. The coil 3a is formed, and a gap formed between the ends of the interlayer insulator 2 protruding from the end face of the sheet-like conductor 1 of the elementary coil 3a is filled with synthetic resin to form a resin insulating layer 7. ,
A tape-shaped insulator pasted from the end of the interlayer insulator 2 to the inside of the end face of the sheet-like conductor is embedded in a resin insulating layer 7 formed on both end faces of the element coil 3a. A molded transformer coil featuring: