JPS6314425Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to improvements in coil core type insulating tubes used in dry type transformers.

Coil core type insulation tubes for transformers, reactors, etc.
It is necessary to have not only electrical dielectric strength but also the strength to withstand mechanical forces that occur during short circuits, and to prevent breakage during handling during coil assembly as a core type.

Conventional core-type insulating tubes are made of glass fiber or the like as a base material and are hardened with epoxy resin or the like to have excellent heat resistance and mechanical strength. This insulating tube generally has a high porosity and it is difficult to obtain through-layer pressure resistance, so as shown in Figure 1, the iron core
When winding the coil 4 around the outer periphery of the insulating tube 2 to be fitted onto the outside, the insulating sheet 3 having excellent electrical dielectric strength is wound a necessary number of times, and then the cooling duct spacer 7 for forming the cooling duct 6 is wrapped around the coil 4. The coil 4 was wound so as to be interposed therebetween. In the figure, 5 is a fixing spacer interposed between the iron core 1 and the insulating tube 2.

However, in the conventional configuration described above, when wrapping the insulating sheet 3 around the outer periphery of the insulating tube 2, the insulating sheet 3 tends to wave or bulge at the overlapped portion, and tape or the like is not required to secure the insulating sheet 3. Because of this, the dimensions are large compared to the thickness required for insulation, and the drawback is that it is difficult to obtain accurate outer diameter dimensions. Furthermore, the waving of the insulating sheet 3 crushed the cooling duct 6 and became a factor that inhibited the cooling effect.

This invention focused on the above-mentioned conventional drawbacks and was developed with the aim of improving them.The coil core type insulating tube used in dry type transformers is composed of two layers, an inner layer and an outer layer, and the inner layer is made of heat-resistant material. The outer layer is made of a base material such as polyamide paper with excellent electrical dielectric strength, and these inner and outer layers are integrated with resin to provide mechanical strength and electrical strength. The purpose is to provide a coil insulating tube that satisfies the above requirements at the same time.

An embodiment of the present invention will be described below with reference to FIG. 2, using the same reference numerals for the same members as in FIG.

The insulating tube 2 according to the present invention has a two-layer structure including an inner layer 2a and an outer layer 2b.

The inner layer 2a is made of a material such as glass fiber that has excellent heat resistance and mechanical strength.
b is composed of a material such as heat-resistant polyamide paper with excellent electrical dielectric strength rolled up on the outer surface of the inner layer 2a,
It is solidified and integrated with epoxy resin.

Since the other configurations are the same as those in FIG. 1, corresponding symbols are attached and explanations are omitted.

By having the above-mentioned structure of the present invention, undulations and unevenness are not formed on the outer periphery of the insulating tube 2, the thickness can be reduced, a core-shaped insulating tube with good precision can be obtained, and the overall coil size can be reduced. is also stabilized, and the cooling duct 6 is also secured, preventing the cooling effect from being inhibited.

In particular, the outer layer 2b is not directly affected by the heat from the iron core 1, and the inner layer 2a is made of a material with excellent heat resistance, so when used in dry type transformers with a low heat resistance class. Even if the transformer is There are various effects such as being able to economically produce similar products.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a conventional coil, and FIG. 2 is a cross-sectional view of a coil according to the present invention. 1... Iron core, 2... Insulating tube, 2a... Inner layer,
2b... Outer layer, 3... Insulating sheet, 4... Coil, 5... Fixing spacer, 6... Cooling duct, 7... Spacer for cooling duct. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] An insulating tube is placed around the outer periphery of the core leg via a fixing spacer, and a coil is wound around the outer periphery of the insulating tube via a cooling duct spacer, thereby creating a cooling duct between the insulating tube and the coil. In the coil core type structure of the dry type transformer, the insulating tube is composed of two layers, an inner layer and an outer layer, the inner layer is made of a glass base material with excellent heat resistance and mechanical strength, and the outer layer is made of a glass base material with excellent heat resistance and mechanical strength. A coil core type structure of a dry transformer characterized by being made of a base material such as polyamide paper with excellent dielectric strength, and having these inner and outer layers integrated with resin.