JPH0750589B2 - Electron gun electrode parts processing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for processing an electron gun electrode component, and particularly to an electron gun electrode component in which an end face of an electron beam passing cylinder is inclined with respect to a cylinder center axis. Processing method.

[Conventional technology]

The end surface of the beam passing cylinder of the main lens electrode is tilted with respect to the cylinder center axis in order to concentrate the electron beams on both sides of the color picture tube electron gun to the center on the phosphor screen surface, that is, to achieve a static convergence. For example, the one disclosed in Japanese Patent Laid-Open No. 57-63750 is known.

This method forms an asymmetric electric field between the electrodes by tilting the end faces of the electron beam passing cylinders on both sides of the pair of opposing electrodes with respect to the center axis of the cylinder by a certain amount, and the orbits of the electron beams on both sides are moved toward the center. It is a bend.

[Problems to be solved by the invention]

However, in the electrode having the inclined cylinder according to the above method, there is a problem that the electrode processing accuracy cannot be sufficiently maintained by the press processing method generally used. Hereinafter, this problem will be described with reference to FIGS.

As shown in FIG. 5, the electrode 1 is formed integrally with three adjacent electron beam passing cylinders 2 and 3. The end surface 4 of the central electron beam passage cylinder 2 is formed at a right angle to the center of the cylinder axis, and the end surfaces 5 of the electron beam passage cylinders 3 on both sides are formed with a certain amount of inclination with respect to the cylinder center axis Y.

The electron beam passing cylinders 2 and 3 are generally formed by burring. In this burring process, the edge of the prepared hole is bent in advance, and due to its processing characteristics, the end face tends to fall inward due to elastic deformation after the burring process as shown by the dotted line in FIG. Similar to the bending process, this tendency shows a large value unless the rising height exceeds a certain level, and it is not possible to secure the necessary and sufficient cylindrical accuracy.

FIG. 7 is a diagram for explaining generally known working conditions in bending work. FIG. 7A shows a phenomenon when the rising height is too low, and FIG. 7B shows a sufficient rising height. The case is shown. In FIGS. 7A and 7B, t is the material thickness, R is the bending radius, and h is the rising height. The minimum value of the rising height h for ensuring sufficient bending accuracy (this is called the minimum rising dimension) is expressed by the formula h ≧ 2.5t + R. Since the bending radius R is generally set to about 1/2 of the material thickness t, the minimum rising dimension h needs to be three times or more the material thickness t.

On the other hand, as shown in FIG. 6, the rising height h of the low cylinder side 6
Is molded at about twice the material thickness t, the elastic deformation amount e ₁ at the end 7 of the low cylinder side 6 is a high cylinder side having a necessary and sufficient rising height (3 times or more the material thickness t). As a result, the elastic deformation amount e ₂ of the end face 9 of No. 8 is extremely large. In this way, the amount of elastic deformation of the end surface after forming the cylinder varies depending on the circumference of the cylinder, which reduces the roundness of the inner surface of the cylinder, which impairs the function as the main lens electrode part and lowers the resolution. Will bring.

An object of the present invention is to improve the processing accuracy of a tilted cylinder,
It is an object of the present invention to provide a method of processing an electron gun electrode part capable of maintaining a good resolution of a color picture tube.

[Means for solving problems]

The above-mentioned problem is that a portion near the base of the low cylinder side formed on the low cylinder side is thinned into a ring shape by coining, and then burring is performed so that the thin plate portion remains at the base of the low cylinder side. It is solved by applying.

[Action]

The part corresponding to the root on the low cylinder side is work hardened by coining and is thinned, so
When a cylinder is formed by burring, the amount of elastic deformation of the end surface on the low cylinder side becomes extremely small. That is, the ratio of the cylindrical rising portion to the plate thickness is substantially set to the minimum value of 3
More than double the conditions can be met.

〔Example〕

The basic principle of the present invention will be described below with reference to FIGS. As shown in FIG. 1 (a), the electrode semi-finished product 10 previously molded in a container shape has a certain amount S with respect to the cylinder center axis Y
Eccentric only to provide a dead hole 11. Next, as shown in FIG. 2B, coining is performed in the range of an outer diameter D ′ (outer diameter larger than the outer diameter D of the cylinder shown in FIG. 2) concentrically with the central axis Y of the cylinder, and the material plate thickness is obtained. A thin plate portion 12 having a plate thickness t'of about 1/2 of t is formed. At this time, the excess thickness of coining is absorbed by the waste hole 11, and the diameter of the waste hole is small and becomes 11a. Next, as shown in FIG. 3C, a burring pilot hole 13 is provided eccentric to the cylinder center axis Y, that is, concentric with the dead hole 11. Thereafter, as shown in FIG. 7D, the hole edge portion of the burring pilot hole 13 is burred to complete the formation of the inclined cylinder 14. At this time, the inclination amount of the end portion 15 of the cylinder 14 with respect to the center axis Y of the cylinder can be easily provided by setting the eccentric amount S of the burring prepared hole 13 to a predetermined value. The relative rising dimension of 17 can be easily set to a desired value by changing the dimension of the burring pilot hole 13.

FIG. 2 shows the electrode 18 formed as described above. The end portion 15 of the cylinder 14 of the electrode 18 is inclined with respect to the cylinder center axis Y, and the cylinder rising height h of the low cylinder side 16 is about twice the material thickness t. This cylinder 14 has an inner diameter d and an outer diameter D, and a thin plate portion 12 shown in FIG. 1 (c) remains along the circumference at the root portion 19 of the outer diameter D, and the range of this thin plate portion 12 is It is composed of D'which is larger than D by a certain amount, and the plate thickness t'of the thinned portion is formed to be about 1/2 of the material thickness t.

In such an electrode 18, work hardening occurs around the cylindrical root portion 19 by coining, and this work hardening generally causes a large hardening to reduce elastic deformation of the worked portion. Further, by thinning the cylindrical root portion 19 to about 1/2 of the material thickness, the rising height h of the low cylindrical side 16 is about four times the root plate thickness t ', which is a problem to be solved by the invention. 3 which is the minimum condition for maintaining sufficient machining accuracy explained in the point section.
It is possible to improve the cylindrical machining accuracy to a value that does not cause a problem in fulfilling the required function as the main lens electrode component.

FIG. 3 shows a first embodiment of the present invention. In the above explanation of the basic principle, the inside of the outer diameter D'was entirely thinned, but in the present embodiment, the ring-shaped groove 20 is formed as shown in FIG. 3A so that only the cylindrical root portion 19 is thinned. Then, the thin plate portion 12 is formed, and then burring is performed as shown in FIG. When formed in this way, the region between the ring-shaped groove 20 and the burring pilot hole 13 remains the material thickness t, so the thickness of the side wall of the cylinder 14 formed by burring, especially the high cylinder. A sufficient thickness of the side wall of the side 17 can be secured, and a cylindrical structure having high strength and being difficult to deform can be obtained. In the structure of FIG. 1 described in the explanation of the basic principle, the area between the outer diameter D ′ larger than the outer diameter D of the cylinder and the burring pilot hole 13 is thinned. Since the cylindrical side wall is formed by the burring process, the thickness of the side wall particularly on the high cylinder side 17 becomes excessively thin and the strength cannot be maintained in some cases.

FIG. 4 shows still another embodiment of the present invention. This embodiment is a modification of the embodiment shown in FIG. 1 and FIG. 2, and as described above, since the low cylinder side 16 is elastically deformed more than the high cylinder side 17, the low cylinder side 16 is The thin plate portion (12) is formed so that the thin plate portion (12) remains only around the root portion (19) of the. Even if formed in this way, the same effects as those of the above-described respective embodiments can be obtained.

[Advantages of the Invention] According to the present invention, the processing accuracy of an electrode cylinder having an inclined end portion can be increased to a value sufficient to perform the function of an electrode component, and the resolution is improved.

[Brief description of drawings]

1 (a) to 1 (d) are cross-sectional views of the essential part showing the basic principle of the processing method for obtaining the electrode according to the present invention, and FIG. 2 is the present invention obtained by the processing method of FIG. 3A, 3B and 4A, 4B are cross-sectional views showing the basic principle of the electrode, and FIGS. 3A, 3B and 4A, 4B show the first and second embodiments of the electrode processing method of the present invention. FIG. 5 is a cross-sectional view of a main part, showing a conventional electrode,
(A) is a plan view, (b) is a cross-sectional view, FIG. 6 is an enlarged cross-sectional view of the main part of the inclined cylinder of FIG. 5, and FIGS. 7 (a) and 7 (b) explain general bending conditions. FIG. 12 …… Thin plate part, 13 …… Burring pilot hole, 14 …… Cylinder,
15 …… End, 16 …… Low cylinder side, 17 …… High cylinder side, 18 ……
Electrodes, 19 ... Cylindrical base, 20 ... Grooves.

Claims (1)

[Claims] 1. A method of processing an electron gun electrode component, wherein an electron beam passing cylinder having a cylindrical end surface inclined with respect to a central axis of the cylinder is formed on the bottom of the container-shaped electrode. Has a first hole eccentric to the central axis of the electron beam passage cylinder by a certain amount, and has an inner diameter centered on the central axis of the electron beam passage cylinder and having an inner diameter of the outer diameter of the electron beam passage cylinder. A ring-shaped groove larger than the first hole is formed by coining, is eccentric to the center axis of the cylinder by the predetermined amount, and has a second hole having a diameter determined by the height of the electron beam passage cylinder. And a burring process at the edge of the second hole, centering on the central axis of the electron beam passage cylinder so that the ring-shaped groove remains at the base of the electron beam passage cylinder on the lower cylinder side. Give the above Processing method of the electron gun electrode component and forming a beam passing cylindrical.