JPH01312801A - Formation of insulating coat - Google Patents

Abstract

PURPOSE:To enable the film thickness of an insulating coat to be uniform, prevent electrical characteristics from varying, and prevent insulating paint from being adhered to the edge surface of an element body by heating the element body to 70-150 deg.C, placing it onto two rollers, and then rotating the rollers to allow a film of insulating paint of specified thickness adhered to the cylindrical surface of the rollers to be transferred and adhered to the cylindrical surface of the element body. CONSTITUTION:An element body 3 is loaded into a conveyer consisting of metal mesh, is moved, and then is continuously heated to 70-150 deg.C. While maintaining this temperature, the element body 3 is placed on two rollers 22 and each roller 22 is allowed to rotate in the same direction at the same speed to enable an insulating paint 14 adhered to the cylindrical surface 22 of the roller 22 to become a film of specified thickness corresponding to a specified gap between the cylindrical surface of the rollers 22 and a drip-proof plate 23. Rotation of the rollers 22 allows the element body 3 placed above to rotate and to allow the film of the insulating paint 14 adhered to the cylindrical surface of the rollers 22 to be transferred and adhered to the cylindrical surface of the element body 3. It allows the film thickness of the insulation to be uniform, prevents electrical characteristics of each non-linear resistor from varying, and prevents insulation paint from being adhered to the edge surface of the element body.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for forming an insulating film on the cylindrical surface of a non-linear viI resistor whose main component is zinc oxide, which is applied, for example, to power surge arresters.

[Conventional technology]

FIG. 4(A) is a side view showing a conventionally well-known nonlinear resistor mainly composed of zinc oxide, FIG. 4(B) is a front view showing the nonlinear resistor of FIG. 4(A), and FIG. FIG. 5 is a conceptual diagram showing one step of a conventional insulating film forming method for forming an insulating film on the cylindrical surface of a grooved linear resistor.

In Figure 4 (A) and (B), (1) is a cylindrical nonlinear resistor whose main component is zinc oxide, (3) is the element of this nonlinear resistor, and (4) is the element of this element. It is a delicate insulating coating formed on a cylindrical surface. Also, in Figure 5, Oυ is the work table, 0
3 is the tab placed on this workbench, the wire mesh attached to the tab of the θ ladder, 041 is the insulating paint made of the material of the above insulating coating (4), and 0 is the container containing this insulating paint. be.

Next, the operation of the conventional insulating film forming method will be explained.

First, place the tab 0z on the workbench (Ill) and attach the wire mesh 0z on top of it.Place the required number of the predetermined number of element bodies (3) on top of this wire mesh 0z. .

In Figure 5, 31J1 is a stack of three element bodies (3).
An example is shown in which ml was placed. Then, the insulating paint contained in the container Q51 is sequentially poured from above the predetermined number of element bodies (3) deposited to apply the insulating paint 0 to the entire cylindrical surface of the element bodies (3). The insulating paint that is not applied to the base body (3) passes through the wire mesh and collects on the tab side. When the element body (3) with the insulating paint 041 coated on the cylindrical surface in this manner is dried or fired at a high temperature, it becomes a non-linear resistor (1) with an insulating coating (4) formed on the cylindrical surface. nonlinear resistor fi
+ insulating liquid 11 +41 determines the electrical insulation performance of the cylindrical surface of the non-linear resistor (1), and in the conventional insulating film forming method as described above, a uniform film thickness is obtained on the wire mesh 0. Place a predetermined number of element bodies (3) stacked on top of each other and shoot from above! Since the insulating paint θ is applied to the entire cylindrical surface of the element body (3) by spraying the paint, the thickness of the paint film and therefore the film thickness of the insulating coating (4) becomes uneven, and the individual non-linear resistors f
In addition to causing variations in the electrical characteristics of the i+, since a predetermined number of elements (3) are deposited and the insulating paint is applied from above, the upper end surface of the uppermost element (3) is also coated with insulating paint. Therefore, there were problems to be solved, such as the need to remove the applied insulating paint before drying or firing.

The present invention has been made to solve this problem, and the thickness of the insulating film (4) is made uniform to prevent variations in the electrical characteristics of individual non-linear resistors. An object of the present invention is to obtain a method for forming an insulating film without applying an insulating paint to the end face of the insulating film.

[Means to solve the problem]

The method for forming an insulating film according to the present invention includes a step of heating a cylindrical nonlinear resistor element whose main component is zinc oxide to a temperature of 70 to 150°C, and dipping the lower part of the body into an insulating paint in a tank. The element body is placed on two parallel rollers that are held rotatably in the same direction, and the rollers are rotated in the same direction at the same number of rotations to maintain a predetermined gap from the cylindrical surface of the rollers. The process of applying the insulating paint to the cylindrical surface of the roller to a predetermined thickness and transferring it to the cylindrical surface of the element, and drying the above element with the insulating paint applied to the cylindrical surface at a high temperature. Alternatively, the resistor may be fired to form a non-linear resistor with an insulating film formed on the cylindrical surface.

[Effect]

In this invention, the element body is heated to a temperature of 70 to 150°C and placed on two rollers, and the rollers are rotated to form a coating film of insulating paint of a predetermined thickness on the cylindrical surface of the rollers. Since the insulating film T is transferred onto the cylindrical surface of the element body, the insulating film T formed on the cylindrical surface of the nonlinear resistor becomes uniform.

[Embodiments of the invention]

Fig. 1 is a conceptual diagram showing an insulating paint application device used in an embodiment of the present invention, and Fig. 2 shows the relationship between the heating temperature of the element body and the average film thickness of the insulating paint applied to the cylindrical surface of the element body. FIG. 3 is a characteristic curve diagram showing the relationship between the heating temperature of the element body and the variation in the film thickness of the insulating paint applied to the cylindrical surface of the element body. In FIG. 1, +31,041 is the same as in the conventional insulating film forming method. (2
1) is a tank containing the above-mentioned insulating paint Q41, (22) is two rollers whose lower parts are dipped in the above-mentioned insulating paint
3) is a drip removal plate that maintains a predetermined gap from the cylindrical surface of this roller.

Next, the operation of one embodiment of the present invention will be explained. First, the element body (3) is placed on a conveyor made of metal mesh (not shown) and heated continuously while being moved to a temperature of 70 to 150
bring the temperature to ℃. While maintaining this temperature, the element body (3)
is placed on the two rollers (22), and each roller (22)
When the rollers (22) are rotated in the same direction and at the same number of rotations,
The insulating paint a applied to the cylindrical surface (22) of the roller (2
2) The coating film has a predetermined thickness corresponding to the predetermined gap between the cylindrical surface and the drip removal plate (23). As the roller (22) rotates, the element (3) placed R on it also rotates and the roller (22)
The coating film of the insulating paint αa applied to the cylindrical surface of the element body (3) transfers and adheres to the cylindrical surface of the element body (3). The average film thickness of the insulating paint applied to the cylindrical surface of the element body (3) is related to the heating temperature of the element body (3).7
The most stable film thickness can be obtained in the range of 0 to 150°C (see Part 2). Also, variations in the film thickness of the insulating paint applied to the cylindrical surface of the element body (3), i.e. [(maximum film thickness -
Minimum film thickness)/average film thickness) When the element body (3) with the insulating paint applied to the cylindrical surface is dried or fired at a high temperature (not shown), a non-linear resistor +11 having an insulating coating (4) formed on the cylindrical surface is obtained.

〔Effect of the invention〕

As explained above, this invention involves the process of heating a cylindrical non-linear resistor element whose main component is zinc oxide to a temperature of 70 to 150 degrees Celsius, and immersing the lower part in an insulating paint in a tank to make it rotatable. The element body is placed on two parallel rollers that are held, and the rollers are rotated in the same direction and at the same number of rotations, and the cylindrical surface of the rollers is held by a plate that maintains a predetermined gap with the cylindrical surface of the rollers. The step of applying the insulating paint to a predetermined thickness and transferring it to the cylindrical surface of the element body, and drying or baking the above element body with the insulating paint applied to the cylindrical surface at a high temperature. The process of forming a non-linear resistor with an insulating film formed on the cylindrical surface makes the thickness of the insulating film uniform, preventing variations in the electrical characteristics of each non-linear resistor, and adding insulation paint to the end face of the element. This has the effect that there is no chance of any staining.

[Brief explanation of the drawing]

Fig. 1 is a conceptual diagram showing an insulating paint application device used in an embodiment of the present invention, and Fig. 2 shows the relationship between the heating temperature of the element body and the average film thickness of the insulating paint applied to the cylindrical surface of the element body. Figure 3 is a characteristic curve diagram showing the relationship between the heating temperature of the element body and the variation in the film thickness of the insulating paint applied to the cylindrical surface of the element body. Figure 4 (A) (B) ) are a side view and a front view respectively showing a conventionally well-known non-linear resistor whose main component is zinc oxide.
The figure is a conceptual diagram showing one step of a conventional insulating film forming method. In the figure, +11 is a nonlinear resistor, (3) is an element body, and (4
) are insulating coatings, (141 is an insulating paint, (21) is a tank, (22) is a roller, and (23) is a drip removal plate. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] The process of heating a cylindrical non-linear resistor element whose main component is zinc oxide to a temperature of 70 to 150 degrees Celsius, the lower part of which is immersed in insulating paint in a tank and held in a rotatable manner. The above-mentioned material is placed on a roller, and the roller is rotated in the same direction at the same number of rotations, and the coating is applied to the cylindrical surface of the roller using a drip removal plate that maintains a predetermined gap with the cylindrical surface of the roller. A step of forming an insulating paint into a film of a predetermined thickness and then transfer-coating it onto the cylindrical surface of the element, and drying or firing the element with the insulating paint applied to the cylindrical surface at a high temperature to form a cylinder. A method for forming an insulating film, comprising the step of forming the non-linear resistor with an insulating film formed on its surface.