JPH0447445B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an insulating tube suitable as a core shape of a winding of an electromagnetic induction device such as a transformer.

[Conventional technology]

Conventionally, as this type of insulating tube, there is one used for transformer windings as shown in FIG. 3, for example.
To explain this based on the diagram, 1 is the iron core of the transformer, 2 is an insulating tube fitted to the core, and 3 is a wedge member press-fitted between these to firmly fix the insulating tube 2 to the iron core 1. , 4 is a low-voltage winding wound around the outer periphery of the insulating tube 2, 5 is an insulating tube attached to the outside of this low-voltage winding 4 via a spacer 6, and 7 is wound around the outer periphery of this insulating tube 5. This is a high voltage winding wire.

Insulating tubes used in such transformers are required to have excellent heat resistance, mechanical strength, and dielectric strength, and are conventionally manufactured as follows.

That is, the insulating tube is made of a mixed woven fabric made of thin threads such as glass fiber as a base material, which is coated with or impregnated with a thermosetting resin to make it semi-cured.
This is wound around a core shape many times to obtain a predetermined thickness.
The resin was then heated and hardened to produce a tube as shown in Figure 4.

[Problem that the invention seeks to solve]

As mentioned above, conventional insulating tubes use a thin cloth woven with thin threads as a base material, so the appearance is less uneven and the workmanship is good, but it is necessary to manufacture an insulating tube of a specified thickness. It takes a long time to make a semi-cured base material coated or impregnated with a large amount of resin, and it takes a long time to make the base material into an insulating tube. This requires a long time, has poor workability, and is expensive.

The present invention has been made to solve the above-mentioned problems, and aims to provide an inexpensive insulating tube that has a good appearance and is easy to manufacture.

[Means for solving problems]

The insulating tube according to the present invention uses a plurality of interwoven fabrics having different thicknesses as a base material.

[Effect]

In the present invention, by effectively utilizing a thick base material and a thin base material, a short length and a small number of windings are required to obtain a predetermined thickness while suppressing unevenness in appearance. The time required to produce a semi-cured sheet coated or impregnated with a thermosetting resin and the time required to produce an insulating tube can be reduced.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIG. 1. The insulating tube 8 of the present embodiment has an innermost layer 9 made of a thin mixed woven fabric with a small weave as a base material, and a winding around the outer periphery of the innermost layer 9. It is formed from a center layer 10 made of a thick mixed woven fabric with a large weave as a base material, and an outermost layer 11 made of a base material similar to the innermost layer 9 wound around the outer periphery of this center layer 10, Each layer is coated with or impregnated with a thermosetting resin before being wound onto the respective interwoven fabrics, and this coating treatment is the same as in the prior art.

Next, to explain the manufacturing procedure of the insulating tube 8 according to the above embodiment, first, a sheet made of a thin mixed woven fabric with a small weave coated or impregnated with a thermosetting resin is wound several times around a core shape (not shown). The innermost layer 9 is formed into a cylindrical body. Next, a sheet made of a thick mixed woven fabric with a large weave coated or impregnated with a thermosetting resin is then wound to the required thickness to form the center layer 10. After that, a woven fabric is formed around the outer periphery of the center layer 10. The outermost layer 11 of the insulating tube is formed by winding a sheet of thin mixed woven fabric with small meshes coated or impregnated with a thermosetting resin several times. The sheet for the outermost layer 11 and the sheet for the innermost layer 9 may be the same.

In this way, in the insulating tube 8 of this embodiment, the thin innermost layer and outermost sheet are wound several times, and a thick sheet is used for the center layer, so that it is difficult to obtain a predetermined thickness. A small number of turns is sufficient. Further, since the lengths of the sheets used for the innermost layer 9, the outermost layer 11, and the central layer 10 may all be short, the time required to produce the semi-cured sheet and the insulating tube may be short.
Furthermore, since the innermost layer 9 and the outermost layer 11 of the insulating tube 8 are made of a thin mixed woven fabric with a small weave, the finished appearance is similar to that of conventional products, and the inner diameter of the insulating tube is Wedge driving to the side and winding of the coil conductor to the outer diameter side can be performed without any problems.

In the above embodiment, a sheet made of a thin interwoven fabric with a small weave coated or impregnated with a thermosetting resin was used for both the innermost layer 9 and the outermost layer 11 of the insulating tube. As shown, the inner layer 12 is made of a thick mixed woven fabric with a large weave, and this is wound around a core (not shown), and the outermost layer 13 is made of a thin mixed woven fabric with a small weave. good. In this case, a thick mixed woven fabric with a large weave is used for the inner layer 12, but since it is wound multiple times on the core tube, the innermost sheet is affected by the external pressure of the sheet wound on top of the core tube. Experiments have shown that the material is sufficiently pressed against the shape, leaving the surface without any unevenness. Therefore, by using a thin mixed woven fabric with a small weave for the outermost layer 13, the same effects as in the above embodiment can be obtained.

Furthermore, in each of the above examples, a thin mixed woven fabric with a small weave was used for the outermost layer, but
For example, if the present invention is applied to a device in which the inner diameter side of the insulating tube is important, a thick mixed woven fabric with a large weave may be used as the outermost layer, and the settings of each layer may be changed. Obviously, it can be chosen arbitrarily.

〔Effect of the invention〕

As described above, according to the present invention, since a plurality of mixed woven fabrics with different thicknesses are used as the base material, the production workability is good, the production time is short and inexpensive, and the appearance surface condition is better than that of the conventional one. The effect is that you can obtain something equivalent to .

[Brief explanation of the drawing]

Figures 1a and 1b both show an insulating tube according to an embodiment of the present invention; Figure 1a is a front view;
Figure b is a side view thereof, Figures 2 a and b are views corresponding to Figures 1 a and b showing other embodiments of the present invention, and Figure 3
Figures a and b both show conventional insulating tubes applied to transformers; Figure 3 a is a plan view, Figure 3 a
4 is a longitudinal sectional view thereof, and FIGS. 4a and 4b are views corresponding to FIGS. 1a and 1b showing the insulating tube of FIG. 3. 8, 14... Insulating tube, [9... Innermost layer (thin interwoven fabric), 11, 13... Outermost layer] - (thin interwoven fabric), [10... Center layer (thick interwoven fabric), 12...
...Inner layer] - (thick mixed woven fabric). In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. An insulating tube in which a flexible base material is coated or impregnated with a thermosetting resin to form a semi-cured state, and this is wound around a core to form a cylindrical shape. An insulating tube characterized by using a plurality of mixed woven fabrics with different thicknesses. 2. The insulating tube according to claim 1, wherein the innermost layer and the outermost layer are made of a thin mixed woven fabric, and the center layer is made of a thick mixed woven fabric. 3. The insulating tube according to claim 1, wherein a thick mixed woven fabric is used as the base material of the inner layer, and a thin mixed woven fabric is used as the base material of the outer layer.