JPH08264051A - Insulator with metal fixture - Google Patents

Abstract

PURPOSE: To provide an insulator with a metal fixture capable of preventing the dispersion of the adhesive strength between the porcelain insulator and the metal fixture and being stabilized at a high level. CONSTITUTION: Ceramic sand 3 is stuck in advance at a sand sticking density of 30-60 grain/cm<2> to the surface of an insulator 1 to which a metal fixture is to be connected and the metal is cemented on it. The grain size distribution of the sand 3 is preferably 700-1700μm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a porcelain insulator with a metal fitting cemented with a metal fitting.

Metal fittings are usually joined to the porcelain insulator, for example, a cap fitting is joined to the outside of the head and a pin fitting is joined to the inside of the head of the suspension insulator. Metal fittings are also joined to the upper and lower ends of the long insulator. Cement is used to bond the insulator and the metal fitting, but in order to increase the bonding strength of the cement, ceramic sand is adhered to the surface of the insulator to which the metal fitting is bonded in advance, and The method of cementing the metal fittings is adopted.

[0003] Crushed porcelain was used as the sand for a long time, but recently it was manufactured by the method disclosed in Japanese Patent Publication No. 6-53601 of the present applicant in order to stabilize the quality. Sand with less edges is used. Also, it is empirically known that a sand grain size of about 1000 μm is suitable. However, even if the above-mentioned sand is used, a product having low adhesive strength between the porcelain insulator and the metal fitting may be found by the strength test before shipping.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and provides a porcelain insulator with a metal fitting that can be stabilized at a high level by eliminating variations in the bonding strength between the porcelain insulator and the metal fitting. It was done by.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. In the present invention, a ceramic sand is preliminarily adhered to the surface of an insulator to which a metal fitting is joined, and the metal fitting is cemented to the surface. In the insulator, the sand adhesion density on the insulator surface is set to 30 to 60 particles / cm ² . The particle size distribution of the sand is preferably 700 to 1700 μm, and the sand may be a glaze-free sand or a sand whose surface is covered with glaze.

[0006]

According to the present invention, the sand adhesion density on the insulator surface can be
By setting the amount to 30 to 60 grains / cm ² , it is possible to prevent overlapping of sands and local lack of sand, and it is possible to stabilize the adhesive strength between the porcelain insulator and the metal fitting at a high level.

[0007]

The present invention will be described in more detail below with reference to the illustrated embodiments. In FIG. 1, 1 is a porcelain insulator (suspended insulator), and 2 is its head. A cap metal fitting (not shown) is cemented to the outer peripheral surface of the head portion 2, but the surface of the insulator 1 is glazed in the preceding stage, and a ceramic sand is applied to the surface to which the metal fitting is joined as shown in the drawing. 3 is attached with a glaze and baked.

As described above, the sand 3 has a shape with few edges. For example, as shown in Japanese Patent Publication No. 6-53601, a sand substrate is extruded into noodles, granulated and fired. It is preferable to use one. The particle size distribution of the sand 3 is preferably adjusted to 700 to 1700 μm. This is because if the particle size is smaller than this range, there is little effect to improve the adhesive strength of cement,
On the other hand, if it is rougher than this range, the metal fittings are obstructed by the sand 3 and are not bonded at a predetermined position, or cavities that are the starting points of breakage are likely to occur between the sands.

In the present invention, the sand adhesion density on the surface of the insulator is adjusted within the range of 30 to 60 particles / cm ² . Although the sand adhesion density on the insulator surface has not been controlled in the past, 20-25
Most were about / cm ² . In the present invention, the sand adhesion density on the insulator surface is thus increased to 30 to 60 grains as compared with the conventional case.
By setting / cm ² , the major feature is that the local sand shortage area is eliminated.

Since the sand 3 is for giving an anchor effect to cement, the sand adhesion density is 30
By setting the number of particles / cm ² or more, it becomes possible to eliminate the variation in cement bonding strength in the micro region. If the sand adhesion density is less than 30 grains / cm ² ,
Since the sand 3 does not contact each other, the sand 3 will settle freely inside the lower glaze layer of the surface of the insulator 1 during firing, and it will come into direct contact with the insulator surface without the lower glaze layer, causing a decrease in strength. Was also found.

On the contrary, when the sand adhesion density exceeds 60 grains / cm ² , a phenomenon occurs in which the sands overlap each other on the surface of the insulator, resulting in a defect called sand boro that is peeled off during the firing shrinkage after the adhesion of the sand 3. It is not preferable.

In order to confirm the effects of the present invention described above, the metal fitting was cemented by changing the sand attachment density on the insulator surface, and the adhesive strength of the metal fitting was measured. The insulator is made of porcelain and is a solid long stem insulator with a diameter of 92 mm.
A lower glaze layer having a thickness of m was formed in advance, and a glaze-free sand having a particle size distribution adjusted to 800 to 1600 μm was attached to the upper surface thereof. Table 1 shows the results. The test is conducted in groups of three, and Table 1
Shows the average value.

[0013]

[Table 1]

[0014]

As described above, in the insulator with metal fittings of the present invention, the sand adhesion density on the insulator surface is set to 30 to 60 grains / cm ² , so that sand boro and local sand shortage due to sand overlap can be prevented. There is an advantage that it can be prevented and the bonding strength between the porcelain insulator and the metal fitting can be stabilized at a high level.

[Brief description of drawings]

FIG. 1 is a front view showing a state in which sand is attached to the surface of an insulator.

[Explanation of symbols]

 1 insulator, 2 heads, 3 sands

Claims (4)

[Claims] 1. In an insulator with a metal fitting, in which a ceramic sand is adhered to the surface of an insulator to which the metal fitting is joined in advance and the metal fitting is cemented to the surface, the sand adhesion density of the insulator surface is 30 to 60 particles / cm ² . An insulator with metal fittings that is characterized by 2. An insulator with a metal fitting according to claim 1, wherein the particle size distribution of the sand is 700 to 1700 μm. 3. An insulator with a metal fitting according to claim 1, wherein a non-glaze sand is used. 4. An insulator with a metal fitting according to claim 1, wherein a sand whose surface is covered with glaze is used.