JPS63133427A - Assembly method of electron gun for cathode ray tube - Google Patents

Abstract

PURPOSE:To eliminate the shape change of an inner lead and to prevent the defect of a stem fillet by changing the shape of a stem lug, bringing the stem lug into close contact with a stem inner lead, and fixing them by welding. CONSTITUTION:A bead mount and a stem are positioned. A stem lug 2 embedded in a multiform glass 3 is faced to an inner lead 1 embedded in a fillet 4. An electrode 11 is brought into contact with the inner lead 1 and the shape of the stem lug 2 is changed by applying the first step pressure to it with an electrode 12 to bring into contact with the inner lead 1. The stem lug 2 and the inner lead 1 are welded by resistance welding under the second step pressure. Since the shape of the inner lead 1 is not changed in any process, the defect such as break of the stem fillet is decreased and the yield in production is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a method for welding a stem in the assembly of an electron gun for a cathode ray tube.

(Prior Art) When inserting and sealing an electron gun into the neck of a cathode ray tube, a stem is attached to the electron gun prior to insertion. To attach this stem, weld the electron gun fixing piece (hereinafter referred to as stem lug), which is a part that is fixed to the stem, and the inner lead of the stem to the bead mount with the electron gun components embedded in multiform glass. and then attach the stem. This stem lug is one of the parts for an electron gun that requires strength, and a plate thickness of 0.32 m to 0.5 m is normally used.

In order to weld such a stem lug and an inner lead, either resistance welding or laser welding is used to attach the stem. An example of this case is shown in FIG. When bringing the stem inner lead (2) into contact with the stem lug (3) attached to the multiform glass (3), the stem inner lead (2) is shaped so that it can come into contact with the stem lug (3), and is held in contact with it at a predetermined position.

It is fixed by welding at A. This stem installation requires precision in tilt, rotation, and height, so the position is determined using a jig or device.

There is also one shown in FIG. That is, the inner lead (2) is welded and fixed to the stem lug (0) at B.

In this type of shaping of the inner lead, the stem itself is shaped in advance or the stem is shaped during welding, so the root of the inner lead is deformed during the shaping process.

Various defects occur in the fillet portion. In other words, the fillet part has a chip (2) as shown in Fig. 3, a rack (part) as shown in Fig. 4, a slight chip (9) as shown in Fig. 5, and a small chip in the subsequent process. Defects occur in the fillet portion of the stem, such as distortions that cause

(Problems to be Solved by the Invention) As described above, various defects that occur in the fillet portion of the stem when the stem lug and the stem inner lead are welded together may cause leakage in the cathode ray tube in which the electron gun is installed. This may cause problems such as pressure deterioration and hole clogging. In particular, in recent display tubes, the hole area of the mask has become smaller, so minute chips in the fillet part, which did not cause hole clogging in conventional color tubes, can cause hole clogging, and CRTs This has a major impact on the decline in manufacturing yield.

For this reason, efforts have recently been made to move the inner lead and stem lug closer together at the design stage to avoid forming the inner lead, but even in this case, there are problems with the accuracy of the stem lug attachment position to multiform glass and the positional accuracy of the stem inner lead. Therefore, when positioning the bead mount and stem using a jig or device during welding, the distance between the stem inner lead and stem lug should be 0.2 to 0.5 m.
It is necessary to keep the distance m. Therefore, since the inner lead is shaped when applying pressure with the electrode, the drawback that defects occur in the fillet portion of the wrist stem cannot be eliminated.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned drawbacks and to provide a method for assembling an electron gun that does not cause defects in the fillet portion of the stem.

[Structure of the invention]

(Means for solving the problem) In the assembly method of the present invention, when the stem inner lead and the stem lug are brought into contact and fixed by welding, the stem lug is shaped, and the stem inner lead is brought into close contact with the stem lug and then welded. It is constructed by assembling the electron gun by fixing the electron gun and attaching the stem.

(Function) In the method for assembling an electron gun of the present invention, when the stem lug embedded in the multiform glass is brought into contact with the inner lead of the stem, since the stem lug is shaped, 1. The electron gun and the stem can be welded and fixed in a predetermined manner very well without any defects such as chipping of the fillet portion.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

As shown in Fig. 1 (A), the bead mount and stem are positioned using a jig or device, and the stem lug embedded in the multiform glass ■ and the inner lead embedded in the fillet part are aligned as specified. Make them face each other. Next, as shown in FIG. 1(B), the electrode 1 (11)
Contact the inner lead■. Next, Figure 1 (C)
As shown in the figure, the stem lug (2) is shaped by the first stage of pressure applied by the electrode 2 (12) and brought into contact with the inner lead (ω). In this state, resistance welding is performed by applying pressure in the second stage, and the state in which the stem lug (2) and the inner lead (2) are welded and fixed is shown in FIG. 1(D). C is the welding point.

Welding may be performed not only by resistance welding but also by laser welding or the like. By welding and fixing the stem lug and the inner lead in this manner, the electron gun can be assembled very efficiently and satisfactorily.

It goes without saying that not only the above assembly method but also various modified assembly methods can be obtained according to the gist of the present invention, such as shaping the stem lugs of a single bead mount and assembling an electron gun.

〔Effect of the invention〕

As described above, according to the method of the present invention, when welding and fixing the stem lug and the steam inner lead, the stem lug is shaped and the two are welded and fixed as specified, so the inner lead is not shaped in any process. Therefore, there is almost no occurrence of defects such as chipping of the stem fillet, and the number of fillet defects has been drastically reduced. Therefore, it is possible to contribute to improving the manufacturing yield of cathode ray tubes equipped with the electron gun assembled in this manner.

For example, among defects caused by hole clogging in display tubes, the percentage of defects due to cracks in fillets and minute chips has almost disappeared.

As described above, according to the configuration of the present invention, it is possible to provide a method for assembling an electron gun in which the manufacturing yield is significantly improved.

[Brief explanation of the drawing]

Figures 1 (A), (B), (C), and (D) are explanatory diagrams showing an embodiment of the present invention in the order of steps; Figure 2 is an explanatory diagram of main parts of a conventional electron gun assembly method; FIGS. 4, 5, and 5 are explanatory diagrams showing a state in which defects occur in a conventional stem fillet portion, and FIG. 6 is an explanatory diagram of a main part of another conventional electron gun assembly method. 1... Stem inner lead, 2... Stem lug,
3... Multiform glass, 4... Fillet portion, A, B, C... Welding points.

Claims (1)

[Claims] A cathode ray tube characterized in that in welding and fixing the electron gun fixing piece embedded in the multi-form glass and the stem inner lead, the electron gun fixing piece is shaped so that it comes into contact with the stem inner lead and is welded and fixed as specified. How to assemble an electron gun.