JPH0152855B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an explosion-proof cathode ray tube, and more particularly, to a method for manufacturing an explosion-proof cathode ray tube, in particular, an annular band (hereinafter referred to as a band) having a smaller diameter than the outer circumference is shrink-fitted to the outer circumference of the side wall portion of the face plate of the cathode ray tube. The present invention relates to a method of manufacturing an explosion-proof cathode ray tube that is tightened.

An example of a method for manufacturing an explosion-proof cathode ray tube in which a band is tightened to the outer periphery of a side wall of a face plate of a cathode ray tube by shrink fitting will be described with reference to FIGS. 1 to 4.

That is, the outer periphery of the side wall 3 of a cathode ray tube is formed by connecting a funnel 4 and a net 5 for mounting an electron gun (not shown) to a side wall 3 of a face plate 2 having a fluorescent screen 1 adhered thereon. A tape 6 having strength is wound.

On the other hand, the band 7 is fixed at a predetermined position with a mounting bracket 8 by means such as welding, heated and expanded by, for example, an annular burner 9, and then inserted onto the tape 6 as shown in FIG. The side wall portion 3 is tightened using the force of contraction, and the explosion-proof cathode ray tube is completed.

However, according to such a manufacturing method, when the band 7 is heated and inserted into the side wall 3 as shown in FIGS. In the figure, the lengths of the arrows 11 and 12 indicate the magnitude of the transmission. Next, as this band 7 cools down, the area near the inner periphery is further marked by the arrow 14.
The heat is transmitted as shown by arrow 13 and continues to expand, but near the outer periphery it is transmitted as shown by arrow 13 and is cooled.

That is, in the above-described process, heating and
Band 7
When the two contact each other, compression stress is generated near the outer periphery of the side wall 3, which is not a big problem, but
When the band 7 begins to cool, the vicinity of the outer periphery also begins to cool and tension stress is generated, and if there is a flaw on the surface of the side wall portion 3, this flaw becomes a crack and has the disadvantage that the cathode ray tube is likely to implode.

The present invention has been made in view of the various drawbacks of the conventional art, and it is an object of the present invention to provide a method for manufacturing an explosion-proof cathode ray tube, which will almost never cause the cathode ray tube to implode even if there is a flaw on the surface of the side wall portion 3. It is said that

Next, an embodiment of the method for manufacturing an explosion-proof cathode ray tube according to the present invention will be described with reference to FIGS. 5 and 6.

That is, the funnel 24 is attached to the side wall portion 23 of the face plate 22 on which the fluorescent screen 21 is adhered and formed.
A tape 26 having adhesive strength, for example, is wrapped around the outer periphery of the side wall portion 23 of the cathode ray tube, which is formed by connecting a net 25 housing an electron gun (not shown) therein.

On the other hand, the manufacturing method for the band 27 is almost the same as that of the conventional method until the band 27 is fixed in a predetermined position with a mounting bracket 28 by means such as welding, heated and expanded by, for example, an annular burner 29, and then inserted onto the tape 26.
In this embodiment, at the same time as the band 27 is inserted, high-pressure air 32 is blown from the plurality of holes 31 of the annular pipe 30 near the contact area between the band 27 and the side wall 23 to mainly cool the band 27. It is characterized by

In this way, the band 2 is mainly
By rapidly cooling the side wall 7, tension stress is not generated near the outer periphery of the side wall 23 as shown in FIG. 4 by the conventional manufacturing method. This has the advantage that this flaw will not cause a crack and will almost never cause the cathode ray tube to implode.

In the embodiment described above, the high-pressure air 30 is blown from the plurality of holes 31 of the annular pipe 30, but the invention is not limited to this, and it goes without saying that the gas may be blown by a fan or the like.

[Brief explanation of drawings]

Figures 1 and 2 are diagrams showing an example of a conventional method for manufacturing an explosion-proof cathode ray tube. An elevational view showing the installed state, Figure 3 is an explanatory diagram showing the transfer of heat within the side wall when the band is inserted into the side wall, and Figure 4 is an illustration of the heat transfer within the side wall as the band cools down. 5 and 6 are diagrams showing an embodiment of the method for manufacturing an explosion-proof cathode ray tube of the present invention, and FIG. 5 is an explanatory diagram showing the cathode ray tube and the band being heated. FIG. 6 is an explanatory diagram showing a state in which a band is inserted into the side wall of the cathode ray tube and high-pressure air is being blown. 2, 22... face plate, 3, 23...
Side wall portion, 6, 26... tape, 7, 27... band, 32... high pressure air.

Claims (1)

[Claims] 1. A method for manufacturing an explosion-proof cathode ray tube in which a band is tightened by shrink fitting to the outer periphery of a side wall of a face plate of the cathode ray tube, including the steps of heating the band, and simultaneously inserting the cathode ray tube and blowing gas. 1. A method for manufacturing an explosion-proof cathode ray tube, comprising the step of cooling a contact portion between a band and the outer periphery of the side wall portion, thereby preventing heat shock.