JPH07201293A - Core for deflecting yoke and its manufacture - Google Patents

Abstract

PURPOSE:To provide a core for a deflecting yoke and its manufacturing method so as to eliminate the burr and the edge of divided surfaces in the vicinity of an end part of small diameter of a divided groove. CONSTITUTION:In a core 1 for an approximately cylindrical deflecting yoke where the core is expanded from an end part 7 of small diameter toward an end part 8 of large diameter, a divided groove provided in an axial direction of an inner circumferential surface 2 and an outer circumferential surface 3 and a recessed part 9 provided at the connecting part of the inner circumferential surface 2 to the end surface 7A of small diameter in the vicinity of the end part 7 of small diameter of the divided groove provided in the inner circumferential surface 2 are provided. In the manufacturing method of the core for the deflecting yoke, an upper die having a blade for the divided groove to form the divided groove provided in the inner circumferential surface 2 of the core 1 for the deflecting yoke, and a lower die provided with a projecting part to form the recessed part 9 of the core for the deflecting yoke and a slide groove where the dividing blades of the upper die slide and are fitted to this projecting part are used in the forming process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke core used in a deflection yoke for deflecting an electron beam of a picture tube used in a television or the like, and a manufacturing method thereof.

[0002]

2. Description of the Related Art A deflection yoke equipped with a substantially cylindrical ferrite core is used in a deflection circuit such as a television,
It has horizontal and vertical coils that deflect the electron beam emitted from the cathode of the cathode ray tube in the horizontal and vertical directions to generate a magnetic field for forming a screen. The deflection yoke core is attached to the neck of the cathode ray tube so as to cover the deflection yoke.

In the core for the deflection yoke, grooves for dividing the core are formed on the inner and outer peripheral surfaces from the large diameter end to the small diameter end.

When the dividing groove provided on the inner peripheral surface extends from the large-diameter end portion to the small-diameter end portion, burrs are generated near the small-diameter end portion on the inner peripheral surface, and the deburring and polishing step is performed. In the inside, chipping damage occurred at the small diameter end of the inner peripheral surface dividing groove.

Further, in the molding process for manufacturing the deflection yoke core, when the dividing groove is formed on the inner peripheral surface of the deflection yoke core, the blades for forming the dividing groove of the upper die contact the lower die. There was also the problem of damage or severe wear.

In order to solve the above-mentioned problem, the dividing groove provided on the inner peripheral surface of the deflection yoke core starts from the large-diameter end portion, ends near the small-diameter end portion, and does not reach the small-diameter end surface. A deflection yoke core is known (Japanese Patent Publication No. 60-745).

[0007]

However, this Japanese Patent Publication Sho 6
When the dividing groove provided in the inner peripheral surface of the deflection yoke core disclosed in 0-745 does not reach the small-diameter end surface, damage or wear of the mold and deburring in the molding process are performed. Although it is possible to prevent chipping of the small-diameter end during polishing, as shown in FIG. 4, burrs are generated on the inner peripheral surface small-diameter end and the left and right sides of the division surface near the small-diameter end are edges. Is inevitable. When the deflection yoke core is mounted on the saddle-saddle winding type deflection yoke in recent years, there arises a problem that the coil is disconnected or damaged by the edge of the division surface.

The present invention has been made to solve the above-described problems, and provides a deflection yoke core and a method for manufacturing the same, which eliminates burrs and edges of the dividing surface that occur near the small-diameter end of the dividing groove. The purpose is to provide.

[0009]

In order to achieve the above object, a deflection yoke core according to a first aspect of the present invention is a deflection yoke core having a substantially cylindrical shape extending from a small diameter end portion to a large diameter end portion. Split grooves provided in the inner peripheral surface and the outer peripheral surface in the axial direction, and a recess provided in the connection portion between the inner peripheral surface and the small diameter end surface near the small diameter end portion of the split groove provided in the inner peripheral surface. It is characterized by having.

According to a second aspect of the present invention, there is provided a method for manufacturing a core for a deflection yoke, wherein the dividing grooves are provided on the inner peripheral surface and the outer peripheral surface in the axial direction, and the small-diameter end portions of the dividing grooves are formed on the inner peripheral surface. A method for manufacturing a substantially cylindrical deflection yoke core that spreads from a small-diameter end portion to a large-diameter end portion having a recess provided in a connection portion between an inner peripheral surface and a small-diameter end surface in the vicinity, In the step, an upper die having a blade for forming a division groove provided on the inner peripheral surface of the deflection yoke core, a convex portion forming a concave portion of the deflection yoke core, and the upper die on the convex portion. A molding die having a lower die provided with a groove into which the blade slides and fits is used.

[0011]

According to the deflection yoke core of the first aspect of the present invention, conventional burrs are formed at the connecting portion between the inner peripheral surface and the small diameter end surface in the vicinity of the small diameter end portion of the dividing groove provided on the inner peripheral surface. Since the portion is formed as a concave portion, polishing for deburring in the vicinity of the small diameter end of the dividing groove provided on the inner peripheral surface is unnecessary, and the deflection yoke core is divided and mounted on the deflection yoke. Also in this case, since the edges on the divided surface are eliminated, the coil is not damaged.

According to the method for manufacturing a deflection yoke core according to the second aspect, in the step of molding the deflection yoke core made of a magnetic material, the deflection yoke core provided for the upper die used in the molding die is used. The blade for forming the dividing groove provided on the inner peripheral surface of the core is provided with the blade of the upper die in the groove provided in the convex portion which forms the concave portion of the small diameter end of the deflection yoke core of the lower die. Slide and fit them together to perform compression molding.

[0013]

EXAMPLES Examples of the present invention will be described in detail below.

An embodiment of the deflection yoke core of the present invention shown in FIG. 1 is a substantially cylindrical deflection yoke core 1 extending from a small-diameter end portion 7 to a large-diameter end portion 8 of an inner peripheral surface 2. The inner peripheral surface dividing groove 4 provided in the axial direction, the outer peripheral surface dividing groove 5 provided in the axial direction of the outer peripheral surface 3, and the outer peripheral surface dividing groove 5 provided in the small diameter end surface 7A from the inner peripheral surface dividing groove 4 The small-diameter end surface dividing groove 6 is formed toward the inner side of the inner peripheral surface dividing groove 6, and the concave portion 9 is formed in the connecting portion of the inner peripheral surface 2 and the small-diameter end surface 7A near the small-diameter end portion 7 of the inner peripheral surface dividing groove 4.

Further, the recess 9 shown in the portion A of FIG.
As shown in the enlarged view of the portion A in FIG. 2, the inner peripheral surface dividing groove 4 is cut into a substantially rectangular parallelepiped at the corner formed by the inner peripheral surface 2 and the small diameter end portion 7 in the vicinity of the small diameter end portion 7. It is in the shape of

Next, the operation of the deflection yoke core 1 of the present embodiment having the above-mentioned structure will be described with reference to FIGS. 3 to 6.

FIG. 3 is a cross-sectional view of a conventional deflection yoke core. As shown in this figure, in the conventional case, the inner peripheral surface dividing groove 4 does not reach the small diameter end portion 7. Therefore, the blades for forming the dividing grooves of the upper die 10 used for the forming die do not come into contact with the lower die 11, and burrs are generated in the vicinity of the small diameter end 7 of the inner peripheral surface dividing groove 4. It is designed to prevent chipping damage during polishing.

However, as shown in FIG. 4, a sharp edge 20 is formed at the tip from a portion of the inner peripheral surface dividing groove 4 of the dividing surface near the small diameter end portion 7 to the small diameter end surface dividing groove 6.
For this reason, when the deflection yoke core 1 is divided and attached to the deflection yoke using the saddle type coil, this portion may come into contact with the coil to be scratched or even broken. It was

FIG. 5 is a sectional view of the deflection yoke core 1 in this embodiment. From this figure, the inner peripheral surface dividing groove 4 has a shape in which a portion where the conventional burr has occurred near the small diameter end portion 7 is scraped off by the concave portion 9.
Further, as shown in FIG. 6, the edge 20 of the dividing surface generated in the conventionally used deflection yoke core is scraped by the recess 9.

Therefore, the deflection yoke core 1 according to the present embodiment does not require polishing for deburring, and even when the deflection yoke core 1 is divided and mounted on the deflection yoke.
The edge 20 does not contact the coil.

Next, a method of manufacturing the deflection yoke core 1 of the present embodiment having the above-described structure will be described. Deflection yoke core 1
Is molded using a magnetic material such as ferrite. Figure 7
Shows a molding step of compression-molding the deflection yoke core 1 of this embodiment using a molding die.

The molding die comprises an upper die 10 provided with dividing groove blades 12 for forming the inner peripheral surface dividing groove 4 of the deflection yoke core 1, and a small-diameter end portion 7 of the deflection yoke core 1. The lower mold 11 is provided with a convex portion 13 for forming the concave portion 9, and further has a middle mold 17, a frame mold 15, and a lower mold curved portion 16.

As shown in FIG. 9, the lower mold has a convex portion 13 for forming a concave portion 9 on the small-diameter end portion 7 of the deflection yoke core 1.
In addition, the inner peripheral surface dividing groove 4 of the deflection yoke core 1 of the upper die 10 is
There is provided a slide groove 14 into which the split groove blade 12 for forming the above is slidably fitted.

Therefore, when the deflection yoke core 1 is compression-molded, the dividing groove blades 12 provided in the upper mold 10 are provided.
Slides in the slide groove 14 of the lower mold 11,
It is possible to prevent damage due to abutting of the molds.

As described above, according to the deflection yoke core 1 of the present embodiment, the inner peripheral surface dividing groove 4 is formed at the corner formed by the inner peripheral surface 2 and the small diameter end portion 7 near the small diameter end portion 7. Since it has a shape cut into a substantially rectangular parallelepiped, it is possible to prevent the burr 21 and the edge 20 of the dividing surface which have been conventionally generated in this portion.

Therefore, the step of polishing the burr 21 and the edge 20 can be omitted, and the burr 21 of the deflection yoke core 1 can be omitted.
Also, it is possible to prevent variations in characteristics due to polishing of the edge 20.

Further, when the deflection yoke core 1 is incorporated into the deflection yoke, the coil can be mounted without damaging the coil.

Further, according to the method of manufacturing the deflection yoke core 1 of the present embodiment, the dividing groove blades 12 of the upper mold 10 used for molding the deflection yoke core 1 are the slide grooves of the lower mold 11. Since it is slidably fitted into 14, it is possible to prevent damage and wear due to abutting of the molds.

The present invention is not limited to the above-described embodiments, but various modifications can be made within the scope of the invention.

For example, the concave portion 9 provided in the small-diameter end portion 7 of the deflection yoke core 1 is formed in a substantially rectangular parallelepiped shape in the present embodiment, but is not limited to this shape and may be a triangular drip or a spherical surface. However, the same effect can be obtained.

It goes without saying that the lower die of the molding die used for the production in this case is provided with the convex portion 13 which fits in the above-mentioned shape.

[0032]

According to the deflection yoke core according to the first aspect of the present invention described in detail above, it is possible to prevent burrs generated at the small-diameter end portion of the inner peripheral surface division groove and edges generated on the division surface. The burr and the edge do not need to be polished, and the coil can be mounted without being damaged when it is incorporated in the deflection yoke.

According to the method of manufacturing the deflection yoke core according to the second aspect, the blade for the dividing groove of the upper die used for molding the deflection yoke core slides into the slide groove of the lower die. Since they are fitted together, it is possible to prevent damage and wear due to contact between the molds.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a deflection yoke core of the present invention.

FIG. 2 is an enlarged view of a concave portion of the deflection yoke core according to the present embodiment.

FIG. 3 is a division surface of a conventional deflection yoke core.

FIG. 4 is an enlarged view of portion C of FIG.

FIG. 5 is a split surface of a deflection yoke core according to the present embodiment.

FIG. 6 is an enlarged view of portion D in FIG.

FIG. 7 is an explanatory diagram of a molding step of the method for manufacturing the deflection yoke core of the present embodiment.

FIG. 8 is an enlarged view of a convex portion of a lower die of a molding die used in the method of manufacturing the deflection yoke core according to the present embodiment.

[Explanation of symbols]

 1 deflection yoke core 2 inner peripheral surface 3 outer peripheral surface 4 inner peripheral surface dividing groove 5 outer peripheral surface dividing groove 6 small diameter end surface dividing groove 7 small diameter end portion 7A small diameter end surface 8 large diameter end portion 9 concave portion 10 upper die 11 Lower die 12 Dividing groove blade 13 Protrusion 14 Slide groove

Claims (2)

[Claims] 1. A substantially cylindrical deflection yoke core extending from a small-diameter end portion to a large-diameter end portion, and a dividing groove axially provided on an inner peripheral surface and an outer peripheral surface, and the inner peripheral surface. A deflection yoke core comprising: an inner peripheral surface near the small-diameter end of the divided groove provided; and a recess provided in a connecting portion between the small-diameter end surface. 2. A dividing groove provided on the inner peripheral surface and the outer peripheral surface in the axial direction and a connecting portion between the inner peripheral surface and the small diameter end surface near the small diameter end portion of the dividing groove provided on the inner peripheral surface. A method for manufacturing a substantially cylindrical deflection yoke core that spreads from a small-diameter end portion having a provided recess to a large-diameter end portion, the method being provided on an inner peripheral surface of the deflection yoke core in a molding step. An upper die having a blade for forming a division groove, a convex portion forming a concave portion of the deflection yoke core, and a groove provided with a groove into which the blade of the upper die slides and fits on the convex portion. A method for manufacturing a core for a deflection yoke, comprising using a molding die having a die.