JPH077645B2 - Deflection yoke core - Google Patents

Description

The present invention relates to a core for a high resolution deflection yoke (hereinafter referred to as "core") mounted on a color cathode ray tube.

[Prior Art] FIG. 5 is a perspective view of a conventional core of this type, and FIG. 6 is an exploded perspective view thereof.

In the figure, (2a) and (2b) are a pair of cores that are divided into two in a plane that passes through the axis, and (5) is a coil insertion groove.
A vertical deflection coil and a horizontal deflection coil (not shown) are formed on the inner peripheral surfaces of a) and (2b) so as to extend in the axial direction at predetermined intervals in the circumferential direction. (6) is a core clip, which is a pair of clip grooves (8) provided near the abutting surface (7) of the cores (2a), (2b) divided into two
The cores (2a) and (2b) are integrally connected by elastic force across the a) and (8b).

A "sawtooth wave current" for generating horizontal and vertical deflection magnetic fields is applied to the horizontal deflection coil and the vertical deflection coil of the conventional high resolution deflection yoke, and both coils are
AC loss (copper loss, eddy current loss and skin loss) occurs, and iron loss (hysteresis loss and eddy current loss) occurs in cores (2a) and (2b). Since the frequency is high, large AC loss and iron loss occur, which causes an abnormal temperature rise in each part of the deflection yoke, resulting in deformation resulting in convergence change and color shift on the screen. There is.

The coil insertion groove (5) is provided in order to suppress the temperature rise of the deflection yoke, and the core (2a),
By making the inner peripheral surface (2c) of (2b) as close as possible to the cathode ray tube, the iron loss of the core is reduced and the deflection current is reduced by ensuring the passage in the core of the magnetic flux.
Therefore, the AC loss is reduced to reduce the heat generation amount of the deflection yoke.

[Problems to be Solved by the Invention] Generally, the cores (2a) and (2b) are produced by a firing process of ferrite, but the work of simultaneously forming the coil insertion (5) at the time of press molding of the ferrite raw material is performed. In addition to being difficult, the shrinkage rate of this press-formed product is high at the time of sintering, so that a dimensional error of about ± 0.5 to 1% occurs, and it cannot be used as it is as a core of a high-resolution deflection yoke.

Therefore, from the viewpoint of cost efficiency, the conventional core has a desired inner peripheral surface (2c) and coil insertion groove (5) of the sintered cores (2a) and (2b) by cutting or polishing. It is generally manufactured by a method of finishing to dimensional accuracy.

However, the grooved core has a large dimensional error during sintering, and
Since the hardness of the core is extremely high, its processing is extremely troublesome, and a special processing machine is required, which is expensive.

The present invention has been made for the purpose of solving the above-mentioned problems, and an object thereof is to obtain a core having a high dimensional accuracy and a low price.

[Means for Solving the Problems] In the core for a high-resolution deflection yoke according to the present invention, a separately formed coil groove forming member is circumferentially provided on the inner peripheral surface of a cylindrical core having a smooth inner peripheral surface. The structure is characterized in that it is arranged so as to extend in the axial direction at intervals and is bonded.

[Operation] According to the present invention, a cylindrical core having a smooth inner peripheral surface and a coil insertion groove forming member are separately prepared, and the coil insertion groove forming member is positioned on the inner peripheral surface of the core. Since these are adhered to each other, the processing of each constituent member is facilitated, so that processing with high dimensional accuracy can be performed at low cost. Since the core is obtained by positioning these components and adhering them integrally, a core with high dimensional accuracy can be obtained.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing a deflection yoke core according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view taken along the line II--II in FIG. 1, and FIG. 3 is a groove forming device of this embodiment. Perspective view of the member of
FIG. 4 is a perspective view showing the core of this embodiment, and the same or corresponding portions as those of the conventional example of FIG. 5 are designated by the same reference numerals and detailed description thereof will be omitted.

In the figure, the cores (2a) and (2b) are the inner peripheral surface (2c).
Are formed on a smooth surface. (9) is a plurality of coil insertion groove forming members made of ferrite, the cores (2a), (2b)
Are formed in a shape along the axial direction of the inner peripheral surface of the, and are arranged at predetermined intervals in the circumferential direction, and are fixed by, for example, an adhesive.

(10) is a positioning protrusion formed on the bonding surface of the coil insertion groove forming member (9). As shown in FIG. 4, this protrusion (10) is composed of cores (2a) and (2b). The coil insertion groove forming member (9) is fitted into a positioning recess (11) formed at a predetermined position on the inner peripheral surface (2c) to position each coil insertion groove forming member (9) at a predetermined position.

In the above embodiment, the positioning protrusion (10) is formed on the bonding surface of the coil insertion groove forming member (9), and the core (2
a), (2b) on the inner peripheral surface (2c) at a predetermined position,
The recess (11) for positioning into which the (0) is fitted is formed. On the contrary, the recess (11) is formed in the coil insertion groove forming member (9) and the inner circumferences of the cores (2a) and (2b) are also formed. A protrusion (10) may be provided on the surface (2c).

In the above embodiment, the positioning protrusion (10) and the recess (11) are provided, but the positioning means is not limited to this example, and the positioning protrusion (10) and the recess ( Instead of providing 11), the coil insertion groove forming member (9) may be adhered to a predetermined position using a positioning jig.

[Effect of the Invention] According to the present invention, a plurality of coils are formed by adhering a coil insertion groove forming member at a predetermined interval in the circumferential direction to the inner peripheral surface of a cylindrical core whose inner peripheral surface is formed as a smooth surface. Since the housing groove is formed, the coil housing groove is formed at the same time when the ferrite raw material is press-molded and sintered, or by machining the flat inner peripheral surface of the core after sintering. Compared with the coil insertion groove, it is possible to obtain a core for a high resolution deflection yoke, which is not only extremely easy to process but also has high dimensional accuracy and is low in cost.

[Brief description of drawings]

FIG. 1 is a perspective view showing a core of a high resolution deflection yoke according to an embodiment of the present invention, FIG. 2 is a partially enlarged sectional view taken along the line II--II in FIG. 1, and FIG. FIG. 4 is a perspective view of the coil insertion groove forming member, FIG. 4 is a perspective view of the same cylindrical core, FIG. 5 is a perspective view of a conventional high resolution deflection yoke core, and FIG. 6 is an exploded perspective view of this conventional example. is there. (2a), (2b) ... core, (2c) ... inner peripheral surface of core, (5)
... Coil insertion groove, (9) ... Coil insertion groove forming member. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A cylindrical core whose inner peripheral surface is finished to be smooth, and a shape extending along the axial direction of the inner peripheral surface of the cylindrical core. A deflection yoke core comprising: a plurality of coil insertion groove forming members, which are arranged at predetermined intervals in the circumferential direction on the surface and are integrally fixed to each other to form a plurality of coil insertion grooves.