JPH02207440A - Reinforced cathode-ray tube - Google Patents

Abstract

PURPOSE:To prevent generation of deterioration due to heating at the time of exhaust by forming reinforcing metal fittings coated with protective films of a clamping band and fastening rags made of a material resisting to heating at the time of exhaust. CONSTITUTION:Reinforcing metal fittings 8 coated with protective films are formed of a clamping band 10 and fastening rags 11 made of a material resisting to heating at the time of exhaust. For instance, in case of reinforcing metal fittings for a small-sized tube, the clamping band 10 and fastening rags 11 are integrally formed of a usual soft steel plate and the surfaces thereof is all applied with aluminum plating. Further, in case of reinforcing metal fittings a large-sized tube, the clamping band 10 and the fastening rags 11 are separately made, followed by welding assembly, to be thus applied with aluminum plating.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reinforced cathode ray tube that can be mass-produced with high yield.

[Conventional technology] In cathode ray tubes, the inside of the tube is evacuated to a high vacuum.

Pressure equivalent to atmospheric pressure is applied from outside the glass bulb of a cathode ray tube, so if the glass bulb, which is the tube body, is scratched or subjected to an impact, it will suddenly break and implode, causing the glass to scatter. There is a risk of Various measures have been taken to suppress the occurrence of such implosion accidents, but
Currently, the outer circumference of the skirt of the glass bulb panel of a cathode ray tube (usually this side is the largest outer circumference) is tightened from the outside with a metal band to relieve stress caused by atmospheric pressure and make it difficult for cracks to propagate. Even if the airtightness of the glass is broken, there is a widely used method to avoid the occurrence of implosion that would cause the glass to scatter over a wide area.

Normally, the implosion prevention method of tightening the vicinity of the maximum outer periphery of the tube with a metal band has been carried out after the cathode ray tube has been assembled and the heating and exhausting work has been completed.

However, during exhaust work in cathode ray tubes, a pressure difference is gradually created between the inside and outside of the glass bulb due to the atmosphere, and in addition, in order to release the adsorbed gas from the surface of each member of the cathode ray tube,
The temperature in the heating furnace is raised to about ℃, which generates stress in the glass bulb, making it more likely to implode. Further, after the inside of the glass bulb has been evacuated to a high vacuum, it is taken out of the evacuation heating furnace and rapidly cooled, thereby generating a large stress in the glass bulb. Therefore, there is a high risk that the cathode ray tube will implode during the evacuation operation. especially,
Recently, large, flat-panel cathode ray tubes have become popular, but such tubes have the problem of being more susceptible to implosion.

For this purpose, for example, Japanese Patent Application Laid-Open No. 62-5533 discloses a cathode ray tube manufacturing method in which the vicinity of the panel skirt of the bulb is tightened with a metal band before performing the exhaust operation. .

However, in this case, insufficient consideration was given to the fact that the pipe body would be heated to high temperatures during exhaust work, and for example, a tape-shaped heat-resistant insulation material that was wrapped around the glass panel skirt surface as a cushioning material under the metal band was used. An adhesive is applied to make the winding work easier, but this adhesive burns when heated during exhaust, contaminates the inside of the exhaust furnace and the cathode ray tube itself, and also reduces the explosion-proof effect. There were other problems. On the other hand, in order to improve the heat resistance of reinforcing metal fittings, for example,
-81843 publication describes a metal band of 0.01 to 0.
Coating with a galvanized layer containing 0.3% aluminum is disclosed, which is approximately 4% of the exhaust heating process.
There was a problem that the film might peel off at 00°C.

[Problems to be Solved by the Invention] The present invention does not have the problems of the above-mentioned conventional technology, and even if a reinforcing metal fitting is attached prior to the exhaust process.

To provide a reinforcing layer cathode ray tube in which a protective coating of a reinforcing metal fitting is not deteriorated by heating during exhaust and can be sold as is.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, the front of the tube close to the display surface, near the maximum outer periphery, is provided with implosion prevention reinforcing metal fittings through a non-combustible cushioning material. In a reinforced layer cathode ray tube manufactured by tightening from the outside and then heating and exhausting, the reinforcing metal fittings, including a protective coating, are made of a material that can withstand heating during exhaust, and are made of a tightening band and a mounting lug. I decided to form it. Specifically, for example, reinforcing metal fittings,
Both may be formed from a tightening band and a mounting lug made of ordinary steel coated with aluminum plating.

[Works]Although core aluminum plating is somewhat expensive, it has a heat resistance temperature of about 350°C, whereas zinc plating, which has been widely used for rust prevention on steel surfaces because it is cheap, has a heat resistance temperature of about 350℃. It is as high as about 650°C, and can sufficiently withstand the heating temperature of about 450°C during exhaust from a cathode ray tube. Aluminum plating.

Even after heating and exhausting, it has sufficient rust prevention properties such as preventing the formation of red rust, and in terms of cost, it is cheaper than nickel plating. Cathode ray tube reinforcing metal fittings generally have no bearing on the appearance of the equipment in which they are used, such as television receivers, and therefore, the condition of the plating on their surfaces may vary somewhat as long as they maintain the ability to prevent rust. There is no problem even if it doesn't look good anymore.

[Example] Figure 1 shows an example of the present invention, with the reinforcing metal fittings installed,
In Figure 0, which is a side view showing the state in which the exhaust work is being performed,
1 is a panel portion, 2 is a funnel portion, 3 is a tube body, 4 is a neck portion, 5 is an electron gun structure, 6 is a glass stem, 7 is a nonflammable buffer material, 8 is a reinforcing metal fitting, and 9 is an exhaust pipe. In the exhaust process, the exhaust pipe 9, which is installed through the glass stem 6, is heated to about 400°C in an exhaust furnace to release the gas adsorbed on the surface of each member of the cathode ray tube.
The gas inside the pipe is sucked out by the exhaust pump.

As the non-combustible cushioning material 7, for example, a glass cloth tape without adhesive applied is used, but since it is difficult to wrap the tape as it is, adhesive is applied to both ends of the glass cloth tape in the width direction. Wrap it in a composite tape with cotton tape attached. This cotton tape is peeled off after the reinforcing metal fittings 8 are attached on top of the nonflammable cushioning material 7. This way, the cotton tape or adhesive will not burn inside the exhaust furnace and contaminate the interior of the exhaust furnace or the cathode ray tube itself.

The reinforcing fitting 8 is generally formed of a tightening band and a mounting lug. FIG. 2 shows an example of a reinforcing metal fitting for a small pipe, in which a tightening band 10 and a mounting lug 11 are integrally molded from an ordinary mild steel plate, and the whole is plated with aluminum. Further, FIG. 3 shows an example of a reinforcing metal fitting for a large pipe, in which the tightening band 10 and the mounting lug 11 are made separately, and after welding and assembly, the whole is plated with aluminum. If the fastening band is manufactured in parts as shown in FIG. 3, it is possible to use a material with high strength for the fastening band, which has an extremely simple shape.

Generally, the reinforcing metal fitting 8 is installed by wrapping the nonflammable cushioning material 7 around the panel skirt of the glass bulb of the tube body 3, and then molding it into an appropriate shape and size and firing it. Since the coefficient of thermal expansion of ordinary metal is larger than that of glass, it is necessary to keep the panel skirt of the glass bulb tightened by the reinforcing fitting 8 (actually the tightening fitting 10) even during evacuation. It is necessary to appropriately set and manage the dimensions of reinforcing metal fittings. In the worst case, during the evacuation process, the tightening may loosen and fall off. Normally, the dimensional change absorption effect of non-combustible cushioning material is effective,
Although it will not reach that point, there is a risk that the tightening will loosen and the implosion prevention effect will be reduced.

This situation can be prevented with proper design and management, but it is recommended that at least the tightening band of the reinforcing metal fittings be made of a material with a thermal expansion coefficient lower than that of ordinary steel and similar to glass, such as stainless steel. This makes work management relatively easy.

[Effects of the Invention] As explained above, according to the present invention, even cathode ray tubes with flannel panels for dolls can be manufactured at a high yield without implosion during the exhaust process, and furthermore, reinforcing metal fittings can be removed after exhaust. Almost no deterioration of the anti-rust protective coating is observed, and high mass productivity is achieved.

[Brief explanation of the drawing]

Figure 1 shows one embodiment of the present invention, with the reinforcing metal fittings installed,
FIG. 2 is a side view showing a state in which the pipe is waiting for exhaust work, FIG. 2 is a perspective view showing an example of a reinforcing metal fitting for a small pipe, and FIG. 3 is a perspective view showing an example of a reinforcing metal fitting for a large pipe. 1...Panel part, 2...Funnel part, 3...
・Tube body, 4... Neck part, 5... Electron gun structure,
6...Glass stem, 7...Nonflammable cushioning material,
8... Reinforcement fittings, 9... Exhaust pipe, 10...
Tightening band.

Claims (1)

[Claims] 1. Manufactured by tightening the front of the tube close to the display surface, near the maximum outer periphery, from the outside with a reinforcing metal fitting to prevent implosion through a non-flammable cushioning material, and then heating and exhausting the area. A reinforced cathode ray tube, characterized in that the reinforcing metal fittings are formed of a tightening band and a mounting lug made of a material that can withstand heat during exhaust, including a protective coating for rust prevention. tube. 2. The reinforced cathode ray tube according to claim 1, wherein the reinforcing metal fittings are formed of a tightening band and a mounting lug, both of which are made of ordinary steel coated with aluminum plating.