JP3395587B2 - Picture tube - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a picture tube reinforced by an explosion-proof reinforcing band, and more particularly to the shape of a shrink-fit type explosion-proof reinforcing band.

[0002]

2. Description of the Related Art Conventionally, in order to prevent the implosion of a picture tube, an explosion-proof reinforcing band is attached to the side surface of the front panel of the picture tube.

As shown in FIG. 1, the explosion-proof reinforcing band 6 is
By tightening the front panel side surface portion 4, the tensile stress generated in the front panel side surface portion 4 is reduced, the generation of cracks at the time of impact is suppressed, and the progress of cracks at the time of breaking is delayed. As shown in FIG. 2, the front panel side surface portion 4 of the picture tube 1, particularly the vicinity of the mold match line 10 (the boundary line between the upper mold and the lower mold when molding the front panel) is bonded via the adhesive tape 9. By tightening with the explosion-proof reinforcing band 6, a force that cancels out the unevenness of the stress distribution of the glass bulb 2 due to the pressure difference inside and outside the picture tube 1 is generated, and the explosion-proof effect is obtained.

As a conventional general explosion-proof reinforcement band of a picture tube, a shrink-fit type explosion-proof reinforcement band is adopted. This heats and thermally expands a metal band having an inner peripheral length slightly shorter than the outer peripheral length of the front panel side surface, and then cools and shrinks the metal band after mounting it on the front panel side surface portion to tighten the front panel side surface portion. .

By the way, in recent years, the size of a picture tube has been increasing, and in order to obtain sufficient reinforcement strength in a large picture tube,
As shown in FIG. 2, a folded-back explosion-proof reinforcing band 6 is used that is folded back along the length direction. As shown in FIG. 7, in the folded-type explosion-proof reinforcing band 6 having such a small radius of curvature, cracks 12 are easily formed at the tip of the folded-back portion 7, and rust is generated in the cracked portion 12 in the material of the plated steel sheet. However, there is a problem that the anticorrosive effect of plating is significantly reduced.

Therefore, as shown in FIG. 8, the radius of curvature of the folded-back portion 7 is increased so that the folded-back portion 7 has a bulge so that cracks at the tip of the folded-back portion 7 are prevented from occurring and the rust preventive effect by plating is not deteriorated. I am trying. FIG. 8 shows such a conventional shrink-fit type explosion-proof reinforcing band 6 for a picture tube 1
The front panel side surface part 4 of FIG.

[0007]

However, as shown in FIG. 8, the picture tube 1 using the conventional explosion-proof reinforcing band 6 is used.
When swelling is performed, the bulging portion 8 at the tip of the explosion-proof reinforcing band 6 approaches the front panel side surface portion 4 at the time of shrink fitting, while a gap is provided between the portion other than the bulging portion 8 and the front panel side surface portion 4. However, there is a problem in that the uniformity of pressurization on the side surface portion 4 of the front panel is reduced and the reinforcing effect is reduced.

Further, as shown in FIG. 9, when the adhesive tape 9 is wound while being displaced from the specified position, the bulging portion 8 of the explosion-proof reinforcing band 6 comes into contact with the side surface portion 4 of the front panel during shrink fitting. As a result, the thermal shock 11 (conceptual diagram) is generated, so that there is a problem that the strength of the side surface portion 4 of the front panel is lowered and a crack is generated in the folded portion 7 of the explosion-proof reinforcing band 6.

The present invention has been made to solve the above problems, and prevents the occurrence of thermal shock at the side surface of the front panel when the folded-type explosion-proof reinforcing band is shrink-fitted and attached to the picture tube. In addition, the present invention provides an explosion-proof reinforcing band capable of uniformly pressing the side surface portion of the front panel and obtaining a sufficient reinforcing effect even for a large-sized picture tube.

[0010]

In order to solve the above problems, a picture tube according to the present invention is provided with a glass bulb comprising a front panel and a funnel, and an explosion-proof reinforcing band is attached to a side surface of the front panel. A fold-back portion is provided at one end portion in the width direction of the explosion-proof reinforcing band, the fold-back portion has a bulge portion that bulges only outward with respect to the front panel side surface portion, and the fold-back portion is the It is characterized in that it is separated from the side surface portion of the front panel (Claim 1).

With this structure, since the folded-back portion has the bulged portion having a large radius of curvature, it is possible to prevent the folded-back portion from cracking, and the bulged portion is provided only outside the side surface portion of the front panel. Therefore, the thermal shock does not occur on the side surface of the front panel and the folded portion due to the contact between the bulge portion and the side surface portion of the front panel.

The explosion-proof reinforcing band is a strip-shaped plate body folded back along the length direction to form a folded portion at one end in the width direction, and the folded portion has a cross-sectional shape in the width direction. Is preferably substantially circular (claim 2).

By thus making the cross-section of the folded-back portion substantially circular, it is possible to effectively prevent the occurrence of cracks in the folded-back portion.

The explosion-proof reinforcing band is preferably a metal plate plated with rust-proof (claim 3).

Further, the thickness of the folded portion of the explosion-proof reinforcing band (the thickness of the cross-section in the width direction of the explosion-proof reinforcing band) is preferably 1.1 to 1.5 times the thickness of the plate-like body ( Claim 4).

By thus defining the radius of curvature of the folded portion, the explosion-proof reinforcing band of any thickness can be
It is possible to reliably prevent the occurrence of cracks in the folded portion, and to provide an explosion-proof reinforcing band suitable for various picture tubes.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a side view of the picture tube of the present invention (the neck portion is omitted). In FIG. 1, a picture tube 1
Is a funnel 5 connected to the front panel 3 and its rear part.
An electron gun (not shown) inserted into a rear opening (not shown) of the funnel 5 and an explosion-proof reinforcing band 6 are attached to the side surface portion 4 of the front panel.

FIG. 2 shows a cross section of the glass bulb 2 where the explosion-proof reinforcing band 6 is attached. In the vicinity of the mold match line 10 on the side surface portion 4 of the front panel, a thickness of about 0.
An adhesive tape 9 having a width of 2 [mm] and having substantially the same width as that of the explosion-proof reinforcing band 6 is wound, and the explosion-proof reinforcing band 6 is mounted thereon. The explosion-proof reinforcing band 6 is folded back along the length direction to have a double structure to enhance the reinforcing effect.

As shown in FIG. 3, the explosion-proof reinforcing band 6 is
The folded portion 7 has a substantially circular cross section in the width direction. The folded-back portion 7 has a bulge portion 8 that bulges outward only with respect to the front panel side surface portion 4, and the side facing the front panel side surface portion 4 is flat. The explosion-proof reinforcement band 6 does not come into contact with the front panel side surface portion 4 because the adhesive tape 9 is interposed, and the folded-back portion 7 bulges only outward with respect to the front panel side surface portion 4. The band 6 and the side surface portion 4 of the front panel are reliably separated from each other.

Further, as shown in FIG. 4, even if the adhesive tape 9 is wound off from the specified position, the explosion-proof reinforcing band 6 and the side surface portion 4 of the front panel can be reliably prevented from contacting each other, and the thermal It is possible to prevent the occurrence of shock.

Further, since the explosion-proof reinforcing band 6 does not have the bulge portion 8 on the surface facing the front panel side surface portion 4, the front panel side surface portion 4 can be uniformly pressed over the entire circumference, and is sufficiently reinforced. The effect can be obtained.

As shown in FIG. 3, the radius of curvature of the cross section of the folded-back portion 7 in the width direction of the explosion-proof reinforcing band 6 (half the thickness t of the folded-back portion 7) is 1.1 to 1.5 of the plate thickness. It is preferably double. If this value is less than 1.1 times, the folding part 7
The cracks are likely to occur. On the other hand, when it is larger than 1.5 times, there arises a problem that the force by which the folded-back portion 7 tightens the side surface portion 4 of the front panel decreases or the variation increases.

An example of the explosion-proof reinforcing band of the present invention is as follows:
In a 32-inch picture tube, the width is 55 [mm], the thickness is 1.2 [mm], and the material is a cold-rolled steel plate, and the surface is plated with aluminum. The folded-back portion 7 has a substantially circular cross section, and the radius of curvature (half the thickness of the folded-back portion 7) is about 1.4 [mm].

Next, a method of manufacturing the explosion-proof reinforcing band will be described. 5 and 6 show a pair of rolls for roll-forming the folded-back portion of the explosion-proof reinforcing band according to the present invention.
0 and FIG. 11 show the folded portion 7 of the conventional explosion-proof reinforcing band.
The roll which shape | molds is shown.

As shown in FIG. 10, in the conventional explosion-proof reinforcing band, the folded portion 7 and the bulge portion 8 are formed by passing a strip-shaped metal plate between the pair of rolls 13. As shown in FIG. 11, the roll 13 is provided with a groove portion 14 corresponding to the bulge portion 8 on both surfaces thereof. With such a pair of rolls 13, the bulge portion 8 as shown in FIG. 8 is formed.

On the other hand, as shown in FIGS. 5 and 6, the pair of rolls 13 used for forming the explosion-proof reinforcing band of the present invention corresponds to the bulge portion 8 of the explosion-proof reinforcing band on the surface of one roll. The groove 14 is provided, and the surface of the other roll is flat. As a result, the bulge portion 8 as shown in FIG. 3 is formed.

[0028]

As described above, according to the present invention, the fold-up portion of the explosion-proof reinforcing band is provided with the bulge toward the outside of the side surface of the front panel, and the fold-back portion and the side surface portion of the front panel are reliably separated from each other. Therefore, while preventing the thermal shock that occurs at the side part of the front panel and the folded part of the explosion-proof reinforcement band and the resulting cracks in the folded part, the deterioration of the reinforcement effect of the explosion-proof reinforcement band is suppressed and the quality is stable. A picture tube can be supplied.

[Brief description of drawings]

FIG. 1 is a partially omitted side view of a picture tube of the present invention.

FIG. 2 is a partial sectional view of the vicinity of the explosion-proof reinforcement band mounting part

FIG. 3 is an enlarged cross-sectional view of the folded portion of the explosion-proof reinforcement band.

FIG. 4 is an enlarged cross-sectional view of the folded portion of the explosion-proof reinforcement band.

FIG. 5 is a view showing an apparatus for manufacturing an explosion-proof reinforcing band used for the picture tube of the present invention.

FIG. 6 is a partially enlarged view of the manufacturing apparatus for the explosion-proof reinforcement band.

FIG. 7 is an enlarged sectional view of a folded portion of a conventional explosion-proof reinforcing band.

FIG. 8 is an enlarged cross-sectional view of a folded portion of a conventional explosion-proof reinforcing band.

FIG. 9 is a conceptual diagram showing a state of thermal shock by a conventional explosion-proof reinforcing band.

FIG. 10 is a view showing a conventional apparatus for manufacturing an explosion-proof reinforcing band.

FIG. 11 is a partially enlarged view of the conventional apparatus for manufacturing the explosion-proof reinforcing band.

[Explanation of symbols]

1 picture tube 2 glass bulbs 3 front panel 4 Front panel side 5 funnel 6 Explosion-proof reinforcement band 7 Folding part 8 bulge

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Claims (4)

(57) [Claims] 1. A picture tube comprising a glass bulb composed of a front panel and a funnel, wherein an explosion-proof reinforcing band is attached to a side surface of the front panel, wherein a folding-back portion is provided at one end of the explosion-proof reinforcing band in the width direction. The cathode-ray tube, wherein the folded-back portion has a bulge portion that bulges outward only with respect to the front-panel side surface portion, and the folded-back portion is separated from the front-panel side surface portion. 2. The explosion-proof reinforcing band is formed by folding a strip-shaped plate body along the length direction to form a folded portion at one end portion in the width direction, and the folded portion is formed in the width direction. The picture tube according to claim 1, wherein the cross-sectional shape is substantially circular. 3. The picture tube according to claim 2, wherein the explosion-proof reinforcing band is a metal plate plated with rust-proof. 4. The picture tube according to claim 2, wherein the thickness of the folded portion is 1.1 to 1.5 times that of the plate-shaped body.