JP6787703B2 - Parts for strain insulators - Google Patents

Description

The present disclosure relates to parts for strain insulators.

Conventionally, in a strain insulator component used for retaining an overhead electric wire, it is necessary to withstand a predetermined tensile load and a predetermined voltage applied by a high potential side metal fitting connected to a transmission line and a ground side metal fitting connected to a support column side. There was, and a polymer insulator was used. (See Patent Document 1)

Japanese Unexamined Patent Publication No. 8-315658

However, in recent years, parts for strain insulators are required to have a higher tensile strength that can withstand high tensions caused by earthquakes, strong winds, and the like. In addition, the transmission line vibrates greatly due to an earthquake, strong wind, etc., and if it is repeatedly vibrated, the transmission line is damaged.

The present disclosure has been devised in view of such circumstances, and provides a strain insulator component that can withstand high tension generated by an earthquake, strong wind, etc. and can attenuate the vibration of a transmission line. The purpose is to provide.

The tension-resistant insulator component of the present disclosure is made of ceramics and includes a cylindrical base portion extending from the first end to the second end. This substrate portion includes a first portion including the first end, a second portion including the second end, and a third portion located between the first portion and the second portion, and has a diameter of the first portion. and the diameter of the second portion is much larger than the diameter of the third portion includes a third portion, a connection portion between each of the first site and the second site. This connecting portion is characterized in that it is curved in a concave shape so that the diameter gradually decreases from the outer peripheral portion of the first portion and the outer peripheral portion of the second portion to the outer peripheral portion of the third portion .

Since the strain-resistant insulator parts of the present disclosure can withstand high tension generated by an earthquake, strong wind, or the like, they can be used for a long period of time. Further, since the vibration generated by an earthquake, a strong wind, or the like can be attenuated, the damage to the transmission line can be reduced.

It is a top view which shows an example of the part for strain insulator of this disclosure schematically.

The parts for strain insulators of the present disclosure will be described in detail below with reference to the drawings. It should be noted that the drawings are schematically shown, and the dimensions and positional relationships of various structures in the drawings are not accurately illustrated.

The tension-resistant insulator component 1 of the present disclosure is made of ceramics and includes a cylindrical base portion extending from a first end 11 to a second end 21. In the following, reference numeral 1 may also be attached to the substrate portion. Further, the first end 11 and the second end 21 are respective ends of the base portion 1 located on the central axis in the longitudinal direction. The substrate portion 1 is a third portion 30 located between the first portion 10 including the first end 11, the second portion 20 including the second end 21, and the first portion 10 and the second portion 20. And. The diameter of the first site 10 and the diameter of the second site 20 are larger than the diameter of the third site 30.

The length of the base portion 1 can be set to, for example, 50 mm or more and 400 mm or less, and the diameter of the first portion 10 and the diameter of the second portion 20 can be set to 20 mm or more and 80 mm or less. Further, the diameter of the third portion 30 is smaller than the diameter of the first portion 10 and the diameter of the second portion 20, and can be set to, for example, 10 mm or more and 50 mm or less.

The tension-resistant insulator component 1 of the present disclosure is used when connecting a power transmission line to a support column. At the time of connection, a fixing bracket connected to a power transmission line and a fixing bracket connected to a support column are attached to the strain insulator component 1. Since the diameter of the first portion 10 and the diameter of the second portion 20 are larger than the diameter of the third portion 30, the fixing bracket is fixed by being caught by a difference in dimensions.

Since the strain insulator component 1 of the present disclosure can withstand high tension generated by an earthquake, strong wind, or the like, it can be used for a long period of time. Further, since the vibration generated by an earthquake, a strong wind, or the like can be attenuated, the damage to the transmission line can be reduced.

Regarding the diameter of the first part 10 and the diameter of the second part 20, if the directionality of the strain insulator part 1 is not required at the time of use, the diameters may be the same, and the directionality is required. If so, it may be different.

The tension-resistant insulator component 1 of the present disclosure preferably has an integrated structure that does not have a joint or an adhesive portion, and is a solid portion that does not have a hollow portion or the like.

In the tension-resistant insulator component 1 of the present disclosure, it is preferable that the connecting portion 40 between the first portion 10 and the third portion 30 and the second portion 20 and the third portion 30 has a curved surface shape. The force applied by the tensile stress applied to the base portion 1 is largely applied between the first portion 10 and the third portion 30, and between the second portion 20 and the third portion 30. Since the connecting portion 40 of the strain insulator component 1 has a curved surface shape, it can withstand the concentration of the force applied by the tensile stress, so that it can be used for a long period of time. In other words, the strain insulator component 1 has high tensile strength.

Further, the ceramics preferably have a Young's modulus of 400 GPa or less. When the Young's modulus value is 400 GPa or less, it approaches the Young's modulus of the metal constituting the transmission line, so that the effect of attenuating the vibration of the transmission line caused by an earthquake, strong wind, or the like becomes large. In particular, the Young's modulus of ceramics is preferably 240 MPa or less. Young's modulus can be determined by the ultrasonic pulse method described in JIS R1602-1995.

The ceramics preferably contain any one of zirconia, silicon nitride, alumina and a composite material thereof as a main component. The composite material is, for example, zirconia-reinforced alumina (ZTA). Since these ceramics have a low Young's modulus and are closer to the Young's modulus value of the metal constituting the transmission line, the effect of attenuating the vibration of the transmission line caused by an earthquake, strong wind, or the like is further increased. The main component here means that it occupies 50% by mass or more of the total 100% by mass of all the components constituting the ceramic. In the case of zirconia-reinforced alumina (ZTA), the content of zirconia and alumina The sum of the content of the main component is the content of the main component.

The components constituting the ceramics can be identified by using an X-ray diffractometer (XRD), and the content thereof can be determined by the Rietveld method. Further, the metal element obtained by the fluorescent X-ray analyzer (XRF) or the ICP (Inductively Coupled Plasma) emission spectroscopic analyzer may be converted into the identified component and obtained.

From the viewpoint of Young's modulus, ceramics preferably contain zirconia as a main component. When ceramics contain zirconia as a main component, the mechanical strength is high, and the mechanical strength is unlikely to decrease even when heated under the scorching sun. The crystal structure of zirconia is preferably tetragonal. The crystal structure of zirconia can be confirmed by an X-ray diffractometer (XRD).

When the ceramics contain silicon nitride as the main component, it is difficult to crack even if it receives high thermal stress, vibration or impact, so the composition formula is Si _6-Z Al _Z O _Z N _8-Z (z = 0.1). With β-sialon represented by 1) as the main phase, the composition ratios of Al, Si, and RE (RE is a Group 3 element of the periodic table) are Al ₂ O ₃ , SiO ₂ , and RE ₂ O ₃ conversion, respectively. ₂ O ₃ is 5 to 50% by mass, SiO ₂ is 5 to 20% by mass, and the balance is silicon nitride containing a grain boundary phase consisting of RE ₂ O ₃ and N, RE-Al-Si-ON. Is preferable.

Further, it is preferable that the substrate portion 1 has a coating film containing fluorine on the substrate portion 1. Such a coating film containing fluorine can prevent dirt from entering the open pores existing on the surface of the substrate portion 1 made of ceramics. Further, since fluorine has water repellency by containing fluorine, it is possible to prevent the adhesion of stains such as water stains, and it is possible to protect the parts for strain insulators from the external environment for a long period of time. The thickness of this coating film can be set to, for example, 25 μm or more and 60 μm or less.

Further, the coating film preferably contains either polytetrafluoroethylene, polyvinylidene fluoride or a perfluoroethylene propene copolymer. These materials contain fluorine and are readily available and can be easily coated.

Further, it is preferable that the color tone of the coating film is different from the color tone of the surface of the substrate portion 1. Since the color tone of the coating is different from the color tone of the surface of the substrate portion 1, the peeling of the coating film can be visually confirmed, and in the production, the coating film is forgotten to be formed or partially covered. It can be easily confirmed that there is no covering film.

The state in which the color tone of the coating film is different from the color tone of the surface of the substrate portion 1 means a state in which the difference in color tone can be visually recognized, and is the difference in color tone feeling defined by the following formula (A). It is preferable that ΔE * ab) is 30 or more.
ΔE * ab = ((ΔL *) 2+ (Δa *) 2+ (Δb *) 2)) 1/2 ... (A)
Here, L * is a brightness index in the CIE1976L * a * b * color space, and chromaticity indexes a * and b * are chromaticity indexes in the color space.

Next, an example of a method for manufacturing the tension insulator parts of the present disclosure will be described.

When the main component of the ceramic is alumina (aluminum oxide), first, alumina powder as a main raw material and powders of calcium oxide, silicon oxide and magnesium oxide which are sintering aids are prepared. Then, after weighing a desired amount, the mixture is placed in a mill together with a solvent and a ball and pulverized until a predetermined particle size is obtained to prepare a slurry.

Next, after adding a binder to the obtained slurry, granules are prepared by spray-drying using a spray dryer.

Next, a columnar molded body having a predetermined size is produced from these granules by a dry pressure molding method such as a cold isotropic molding method (CIP molding). Then, the molded body is machined so that the diameter of the first portion 10 at both ends and the diameter of the second portion 20 are larger than the diameter of the third portion 30 at the center, and the substrate portion 1 is processed. To obtain a molded product.

A molded product may be produced by an injection molding method or a press molding method using pellets produced from the same raw material.

Next, when the obtained molded product to be the substrate portion 1 is made of, for example, alumina, the maximum temperature is set to 1450 to 1750 ° C. in the atmospheric atmosphere, and the holding time at this maximum temperature is set to 1 to 1. It may be fired for 8 hours.

When the main component of the ceramic is zirconia (zirconium oxide), first, a zirconia powder containing a stabilizer component is prepared. The zirconia powder containing the stabilizer component is, for example, 2 mol of zirconium oxide. It is a powder in which yttrium oxide of% or more and 4 mol% or less is solid-dissolved, and is produced as follows. An aqueous solution of the zirconium compound and an aqueous solution of the yttrium compound are mixed so that 2 mol% or more and 4 mol% or less of yttrium oxide is dissolved in zirconium oxide. As such a zirconium compound, for example, zirconium oxychloride can be used, and as the compound of yttrium, for example, yttrium oxychloride can be used.

Then, a slurry is prepared by using a coprecipitation method for obtaining a hydrate by hydrolysis, then dehydrated, dried, and calcined at 500 ° C. to 1200 ° C. to obtain a calcined powder. Then, the calcined powder is pulverized by a wet ball mill or the like and dried to obtain a zirconia powder containing a stabilizer component.

If the average particle size (D ₅₀ ) of the zirconium oxide powder stabilized by yttrium oxide is 0.05 μm or more and 0.2 μm or less, the crystals of zirconium oxide become fine, so that the mechanical strength of the ceramics and Fracture toughness can be increased, and it is more preferable that the average particle size (D ₅₀ ) is 0.05 μm or more and 0.1 μm or less.

Next, the zirconia powder containing the stabilizer component and the sintering aid component are weighed in a predetermined amount, silica sol and a binder are added, and then spray-dried using a spray dryer to obtain an average particle size (D ₅₀ ). For example, granules of 40 μm or more and 55 μm or less are prepared.

Then, the obtained granules can be filled in a molding die to obtain a molded product by a method such as press molding or CIP molding.

Finally, the molded product may be fired in an air atmosphere with a holding temperature of 1400 ° C. or higher and 1500 ° C. or lower and a holding time of 1 hour or longer and 3 hours or lower.

Since the firing conditions such as the maximum temperature and the holding time change depending on the shape and size of the product, they may be adjusted as necessary. Further, if necessary, the surface of the substrate portion 1 may be subjected to processing such as polishing to modify the surface roughness state.

Next, in order to have a coating film containing fluorine on the substrate portion, the following procedure may be carried out. When polytetrafluoroethylene is contained, polytetrafluoroethylene is mixed with an organic solvent such as chloroform, methanol, formic acid, N, N-dimethylformamide, tetrahydrofuran, 1,2-dichloroethane, ethyl acetate, and methyl ethyl ketone to obtain a predetermined concentration. A solution may be prepared and the coated portion may be coated with a spray device. Alternatively, the substrate portion may be dipped in a solution tank to cover it. By masking the uncoated portion in advance, the coating film may not adhere to the uncoated portion. Further, by making the ceramics containing alumina as a main component white and forming a coating portion containing a black pigment, the color tone of the substrate portion and the color tone of the coating portion can be made different.

Further, the strain insulator parts of the present disclosure are not limited to the above-described embodiments, and various changes and improvements can be made without departing from the gist.

1: Base part 10: First part 11: First end 20: Second part 21: Second end 30: Third part 40: Connection part

Claims (7)

It is made of ceramics and has a cylindrical base portion extending from the first end to the second end, and the base portion includes a first portion including the first end, a second portion including the second end, and the first portion. and a third site located between the one-site and said second site, said diameter and the diameter of the second portion of the first region is much larger than the diameter of the third portion, said third portion A connecting portion is provided between each of the first portion and the second portion, and the connecting portion is formed from the outer peripheral portion of the first portion and the outer peripheral portion of the second portion to the outer peripheral portion of the third portion. A component for strain insulators characterized in that it is curved in a concave shape so that its diameter gradually decreases toward . The component for a strain insulator according to claim 1, wherein the ceramic has a Young's modulus of 400 GPa or less. The tension-resistant insulator component according to claim 1 or 2 , wherein the ceramic is mainly composed of zirconia, silicon nitride, alumina, or a composite material thereof. The component for a strain insulator according to claim 3 , wherein the ceramics contain zirconia as a main component. The component for a strain insulator according to any one of claims 1 to 4 , wherein a coating film containing fluorine is provided on the substrate portion. The component for strain insulators according to claim 5 , wherein the coating film contains any one of polytetrafluoroethylene, polyvinylidene fluoride, and perfluoroethylene propene copolymer. The component for a strain insulator according to claim 5 or 6 , wherein the color tone of the coating film is different from the color tone of the substrate portion.

Images