JPH062591B2 - Method for manufacturing glass structure for cathode ray tube - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for manufacturing a glass structure for a cathode ray tube.

[Background technology and its problems]

Generally, a cathode ray tube, especially a color cathode ray tube, is an envelope formed by joining a funnel-shaped funnel made of glass to a panel made of glass, and a tubular neck made of glass is joined to the funnel, and a panel of the envelope. It has an explosion-proof band wrapped around the outer circumference and an electron gun provided in the neck of the envelope, and if various defects occur, the envelope is collected. In the method, the explosion-proof band is removed, a crack is made in a part of the exhaust pipe or the neck, air is introduced, and an acid solution is used or heating is performed to separate the funnel and the panel. Next, after separating the neck or the boundary between the neck and the funnel, a new neck is re-welded and joined to the separated portion to form a glass structure including the neck and the funnel.

Since this re-welding is performed by heating and melting the neck or the boundary portion with a burner, residual strain occurs in the vicinity of the boundary portion between the neck and the funnel. In order to remove this residual strain, after the heating and melting process, the neck 1 of the glass structure is supported face down as shown in FIG. 2, and the strain generating portions of the neck 1 and the funnel 2 are annealed by the annealing furnace 4. .

The heating in this annealing raises the temperature to such an extent that the glass structure does not crack, and deformation occurs at a temperature at which the glass structure exceeds the annealing point, or in the case of the commonly used funnel 2, which exceeds 490 ° C. After heating to a non-existing temperature, for example, about 510 ° C and holding for about 10 minutes,
Gradually cool so that the glass structure does not crack. If this gradual cooling is not performed until the strain point (450 ° C. in the case of the glass of the funnel 2) becomes lower than the strain point at a rate of 5 ° C./minute, the strain cannot be sufficiently removed, and the envelope will be cracked later. ) Etc. cause serious accidents.

In this case, if an attempt is made to heat the strain generation part to a temperature above the annealing point, the temperature of the funnel 2 on the seal edge side becomes lower than that of the structure in the annealing furnace 4 as shown in FIG. In order to obtain proper annealing conditions, the furnace as shown in Fig. 1 is used, or the continuous funnel is used to gradually cool the entire funnel. It is necessary to heat above the point.

As described above, the annealing work, especially the temperature raising and gradual cooling work of the glass structure, needs to be performed extremely slowly, resulting in a long working time and a large-scaled device, which hinders the improvement of work efficiency. It has become.

[Object of the Invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a glass structure for a cathode ray tube, which has been made in order to improve the above-mentioned conventional drawbacks and which has a significantly improved work efficiency.

[Outline of Invention]

The inventor performed an experiment to partially anneal the strain-generating portion after the heat-melting processing so that cracks do not occur even if the annealing rate is increased in the annealing work. If the heating part is heated to a temperature not lower than the strain point of the glass and not higher than the slow cooling point and heated and held to such an extent as to reduce the processing strain, thereafter, the heating and slow cooling for a long time unlike the conventional case is not performed. It was found that there is no problem even if heating and natural air cooling are performed suddenly.

That is, the present invention provides a funnel-shaped funnel made of glass, and a tubular neck made of glass, which is joined to the neck or the boundary between the neck and the funnel by heating and melting to bond the glass structure for a cathode ray tube. After the melting and processing, the vicinity of the processed portion is heated to a temperature not lower than the strain point and not higher than the slow cooling point of the glass, and is held for several minutes or more to carry out annealing, which is a manufacturing method of a glass body for a cathode ray tube.

Example of Invention

The method for manufacturing a cathode ray tube according to the present invention is configured as shown in FIG. 1, and the same parts as those in the conventional example are designated by the same reference numerals.

That is, the vicinity of the neck welded portion of the glass structure composed of the neck 1 and the funnel 2 is cut, and the glass structure in which the new neck 1 is regenerated by heating and melting is put into the annealing furnace 3 and shown in FIG. Heating to various temperatures such as 2
After holding for a minute, the glass structure was taken out into the atmosphere and the magnitude of strain was observed with a strain observing meter. The comparative product was heated to 510 ° C by the conventional method, held for 10 minutes, and then heated at 430 ° C at a rate of 5 ° C / min.
It was gradually cooled to.

As a result, in the present invention, the funnel-shaped funnel made of glass is joined to the neck portion made of glass by heating and melting at the neck or the boundary portion between the neck and the funnel, and then the processed portion is distorted in the glass. The temperature is raised to a temperature not lower than the annealing point and not higher than the annealing point, and is held for several minutes or more to perform annealing.

〔The invention's effect〕

According to this invention, the work efficiency is remarkably improved. That is,
As is apparent from Table 1 above, the prototypes Nos. 2 to 4 of the examples of the present invention show that the time required for heating and cooling is significantly shortened, and there is no residual strain, which is good. ing.

[Brief description of drawings]

FIG. 1 is a sectional view showing a method of manufacturing a glass structure for a cathode ray tube according to an embodiment of the present invention, FIG. 2 is a sectional view showing a method of manufacturing a conventional glass structure for a cathode ray tube, and FIG.
It is a characteristic curve figure which shows the temperature curve of the distortion removal part at the time of annealing process of each sample in a table | surface. 1 ... neck, 2 ... funnel, 3 ... annealing furnace.

Claims (1)

[Claims] 1. A method for producing a glass structure for a cathode ray tube, comprising joining a funnel-shaped funnel made of glass and a tubular neck made of glass to the neck or a boundary portion between the neck and the funnel by heating and melting, and heating and melting. After the processing, the vicinity of the processed portion is heated to a temperature not lower than the strain point and not higher than the slow cooling point of the glass, and is held for several minutes or more to carry out annealing, which is a method for manufacturing a glass body for a cathode ray tube.