JPH04342924A - Manufacture of deflecting yoke core - Google Patents

Abstract

PURPOSE:To provide a homogeneous core having high specific gravity and good dimensional accuracy by providing a compact by a lathe method of a ferrite raw material clay and removing a baseplate from a thin-walled part before or after a firing when mounting the baseplate of the compact via the thin-walled part on the smaller diameter side opening of a deflecting yoke core. CONSTITUTION:A baseplate 15b is mounted via a thin-walled part 15c on the smaller diameter side opening of a deflecting yoke core 15 so as to form a compact, a clay-like ferrite raw material is thrown into a plaster mold having a die surface corresponding to its external surface, then the plaster mold is pressed against the clay while rotating it. Here, upon the formation of the compact, a lathe method is adopted. After the formation, it is dried, and the baseplate 15b is removed from the thin-walled part 15c and fired, or the compact is fired followed by removing the baseplate 15b. Thereby, high circularity, higher specific gravity compared with a powder pressing formation, so that the excellent characteristics, can be obtained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a deflection yoke core used in color TVs, display monitors, etc.

0002

2. Description of the Related Art FIG. 2 is a partially sectional front view of a typical deflection yoke core. In the figure, 1 is a morning glory-shaped deflection yoke core made of a sintered body of ferrite powder, 2 is a dividing groove formed on the opposing surfaces of the outer and inner surfaces of the core 1 to divide the core 1, and 3 and 4 are dividing grooves. 2 are divided cores, 5 and 6 are each divided cores 3 and 4 on both sides of the dividing groove 2.
This is a clip groove formed in the

The above deflection yoke core 1 has dividing grooves 2 after firing.
The core is divided into two parts 3 and 4, and after winding, 1
They are combined into a single unit and used by sandwiching the opposing clip grooves 5 and 6 between the clips.

The conventional manufacturing method for such a deflection yoke core is to first pressure-form ferrite raw material powder using a mold in which convex portions corresponding to the dividing grooves 2 and clip grooves 5 and 6 are formed in advance, and then divide the ferrite raw material powder. A deflection yoke core 1 is obtained by forming a molded body having grooves 2 and clip grooves 5 and 6, and firing the molded body at a high temperature of over 1,000 degrees Celsius.

However, the deflection yoke core 1 obtained by such a pressing method has a problem that its specific gravity is small and that it is deformed during firing due to non-uniform packing density, resulting in poor dimensional accuracy.

[0006] On the other hand, there is a potter's wheel molding method as a method for molding a container-shaped molded body from a clay-formed ferrite raw material. FIG. 3 is a process diagram showing the potter's wheel molding method, in which 11 is a container-shaped plaster mold, 12 is raw clay, 13 is a metal rotating trowel, 14 is a deburring knife, and 15 is a molded body.

[0007] The potter's wheel molding method is generally used to mold containers with a bottom out of clay. The molding method is to first prepare a plaster mold 11 shown in FIG.
As shown in b), raw clay 12 is charged. next(
As shown in c) and (d), a rotating metal trowel 13 is pressed against the raw clay 12, and the raw clay 12 is spread along the plaster mold 11 while rotating the plaster mold 11.
1 to absorb water, and the protruding clay is scraped off with a deburring knife 14 to form a molded body 15 as a container. Next, as shown in (e), when this molded body 15 is heated together with the plaster mold 11, absorption of moisture into the plaster mold 11 and drying are accelerated, and as shown in (f), the molded body 15 shrinks. Then, as shown in (g), plaster mold 11
It can be easily taken out. The molded body 15 taken out is
A container is manufactured by drying and firing.

[0008]

[Problems to be Solved by the Invention] As mentioned above, the potter's wheel molding method using a rotating trowel can be easily applied to molding containers with a bottom, but it is difficult to mold containers with open ends, such as the deflection yoke core 1. In the case of molding a bottomless cylindrical molded body, the rotary trowel 13 comes into contact with the plaster mold 11, which causes wear of the plaster mold 11 and makes it impossible to perform stable molding.

The present invention has been made to solve the above-mentioned problems, and it is possible to easily and efficiently manufacture a deflection yoke core by using a potter's wheel molding method, and to produce a product that is homogeneous, has a large specific gravity, and has excellent quality. The purpose of this study is to propose a method for manufacturing a deflection yoke core that provides the following.

0010

[Means for Solving the Problems] The present invention provides the following method for manufacturing a deflection yoke core.

(1) At the opening on the small diameter side of the deflection yoke core,
A method for manufacturing a deflection yoke core, in which a molded body with a bottom plate attached through a thin wall part is molded from ferrite raw clay using a potter's wheel molding method, and after molding, the bottom plate is separated from the thin wall part and the molded body is fired.

(2) At the opening on the small diameter side of the deflection yoke core,
A method for manufacturing a deflection yoke core, in which a molded body with a bottom plate attached through a thin-walled part is molded from ferrite raw clay using a potter's wheel molding method, the molded body is fired, and then the bottom plate is separated from the thin-walled part.

[0013]

[Operation] In the method for manufacturing a deflection yoke core of the present invention, a mold surface (inner surface) of a shape corresponding to the outer surface of a molded body having a bottom plate attached through a thin wall portion is formed in the small diameter side opening of the deflection yoke core. A raw clay made of a ferrite raw material (a clay-formed ferrite raw material) is put into a plaster mold, and while the plaster mold is rotated, a trowel is pressed against the clay to form a molded body of the above shape using a potter's wheel molding method.

After drying the molded body thus obtained, the bottom plate is separated from the thin wall portion and fired, or the molded body is fired as it is and then the bottom plate is cut off from the thin wall portion to produce a deflection yoke core.

Since the deflection yoke core thus obtained is homogeneous, it undergoes little deformation during firing and has good dimensional accuracy.
A product with high roundness can be obtained. Furthermore, since the specific gravity is greater than that of conventional powder press-molded products, a deflection yoke core with excellent characteristics can be obtained.

[0016]

Embodiments Hereinafter, embodiments of the present invention will be explained with reference to the drawings. FIG. 1 is a sectional view showing the manufacturing method of the embodiment, and in the figure, the same reference numerals as in FIG. 3 indicate the same or corresponding parts.

In FIG. 1, the molded body 15 has a morning glory-shaped core portion 15 having a shape corresponding to the deflection yoke core 1 of FIG.
The bottom plate 15b is attached via a thin wall portion 15c so as to close the opening on the small diameter side of a. The plaster mold 11 has a mold surface 11 corresponding to the outer surface of the molded body 15.
It is a container-shaped mold with a on the inside. The rotating iron 13 is
Although it has a cone shape corresponding to the inner surface of the molded body 15, it is formed to have a smaller diameter than the inner circumference of the molded body 15.

The method for manufacturing the deflection yoke core 1 is first shown in FIG.
A molded body 15 is molded in substantially the same manner as in FIG. 3 using the mold. That is, in the plaster mold 11 of FIG. 1, (b) of FIG.
In the same way, raw clay 12 made of ferrite raw material is charged, and as in FIGS. 3(c) and 3(d), while rotating the plaster mold 11, a metal rotating trowel 13 is pressed against the raw clay 12. The raw clay 12 is spread over the mold surface 11a of the plaster mold 11, and the plaster mold 11 absorbs moisture to form the molded body 1 shown in FIG.
Mold 5. After that, similarly to FIG. 3(e), the molded body 1
5 is heated together with the plaster mold 11, moisture absorption and drying are accelerated, and the molded body 15 contracts as shown in FIG. easily taken out.

The molded body 15 obtained in this way is
After separating the bottom plate 15b from 5c and firing only the core part 15a, or firing the molded body 15 as it is,
The deflection yoke core 1 shown in FIG. 2 is manufactured by separating the bottom plate 15b from the thin portion 15c.

Since the deflection yoke core 1 thus obtained is homogeneous, it undergoes little deformation during firing, has good dimensional accuracy, and has high roundness. Furthermore, since the specific gravity is greater than that of conventional powder press-molded products, a deflection yoke core with excellent characteristics can be obtained. By firing with the bottom plate attached and separating the bottom plate after firing, deformation during firing is prevented.
Dimensional accuracy is further improved.

[0021] Furthermore, the above manufacturing method does not require a mold, and it is possible to produce small quantities and short delivery times. Furthermore, since it is not powder molded, environmental deterioration due to powder scattering is prevented.

Example 1 After adding 7% glycerin, 2% dispersant, and 5% water by weight to Mn-Mg ferrite powder and kneading it into a clay-like form, the plaster mold shown in FIG. 1 was prepared. 11, and while pressing the metal rotary trowel 13, both the plaster mold 11 and the rotary trowel 13 were rotated to form a molded body 15 with a bottom plate 15b. After heating the plaster mold 11 at 60° C. for 30 minutes, the molded body 15 is taken out from the plaster mold 11 and when the bottom plate 15b is poked from the inside of the molded body 15, the thin part 15c is easily broken and the bottom plate 15b is separated from the core part 15a. has been removed.

Thereafter, the core portion 15a is heated at 100° C. for 3 hours to dry it, then heated at 600° C. for 4 hours to burn off the glycerin, and then main fired at 1220° C., resulting in a deflection yoke core 1 with a high degree of roundness. Obtained. The specific gravity of this core is 4.
5, which was larger than the specific gravity of 4.3 obtained by the conventional powder pressing method. Table 1 shows a comparison of the characteristics and dimensional accuracy of this core and the core of the conventional powder press method.

[0024]

[0025]

According to the present invention, a molded body having a bottom plate attached to the opening on the small diameter side of the deflection yoke core is molded, and the bottom plate is removed before or after firing, so that the deflection yoke core can be molded on a potter's wheel. It can be easily and efficiently produced by the method. Furthermore, since the obtained deflection yoke core is homogeneous and has a high specific gravity, it not only has superior properties compared to conventional pressed products, but also has good dimensional accuracy. Furthermore, since no molds are required, it is possible to produce small quantities with short delivery times, and since it is not powder molding, it is possible to prevent environmental deterioration due to scattering of powder. In the present invention, according to the method of separating the bottom plate after firing, since firing is performed with the bottom plate attached, deformation during firing is reduced and dimensional accuracy is further improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a manufacturing method of an example.

FIG. 2 is a front view showing a portion of the deflection yoke core in cross section.

FIG. 3 is a process diagram showing a potter's wheel molding method.

[Explanation of symbols]

1 Deflection yoke core 11 Gypsum mold 12 Raw material clay 13 Rotating trowel 15 Molded object 15a Core part 15b Bottom plate 15c Thin wall part

Claims (2)

[Claims] [Claim 1] A molded body having a bottom plate attached to the small-diameter opening of the deflection yoke core through a thin wall portion was molded from ferrite raw clay using a potter's wheel molding method, and after molding, the bottom plate was separated from the thin wall portion. A method for manufacturing a deflection yoke core, which comprises firing a molded body. [Claim 2] A molded body in which a bottom plate is attached to the small-diameter opening of the deflection yoke core through a thin-walled portion is molded from ferrite raw clay using a potter's wheel molding method, and after firing the molded body, A method for manufacturing a deflection yoke core characterized by separating the bottom plate.