JPS6220225A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To prevent flaw and rack due to an explosion-proof metal ring belt, by cutting the belt at the tip of the joint part of the belt to remove the mold match line part and its adjacent area. CONSTITUTION:An explosion-proof metal ring belt 11 is formed by over-lapping the end parts of the belt and spot-welding 5 the joint part 4 on four points. A cut part 12 is formed by cutting a predetermined length D in the longitudinal direction of the metal belt 11 corresponding so a mold match line 3 and its adjacent area at a joint part tip 4a which touches a panel 1 in the joint part 4 of the metal belt 11. An end part 14 withdrawn due to the formation of the cut part 12 is shaped, through, for example, press working in an inclined face 15 which gradually separates from a panel 1 in the direction approaching the tip on the side touching the panel 1. By that, abutting of the tip against the mold match line 3 is avoided or weakened even if the tip is bent. As a result, flaw and rack on the panel 1 caused by the metal belt 11 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cathode ray tube in which an explosion-proof metal ring is fitted by a shrink-fitting method.

[Summary of the invention]

The present invention relates to a cathode ray tube in which an explosion-proof metal ring including the mold match line of the panel is fitted by shrink fitting, and the mold match line and the portion near it at the tip of the joint of the explosion-proof metal ring. By cutting it out, concentrated loads are prevented and cracks in the panel glass are prevented.

[Conventional technology]

In shrink-fitting, which performs explosion-proof treatment for cathode ray tubes, as shown in Figure 5, a metal ring band (2) smaller than the outer circumference of the glass panel (11) is heated and expanded in advance, and this is attached to the mold mating line (3) of the panel (11). After fitting to the outer periphery including A polyester tape or a true-melt tape (glass cloth shape) is placed between the rings (2).

The explosion-proof metal ring band (2) is made by bending the band into a ring shape as shown in Figure 6, overlapping the ends, and forming the joint part (4).
It is constructed by spot welding (5).

[Problem that the invention seeks to solve]

When the explosion-proof metal ring (2) is fitted to the panel (1), the joint part of the metal ring (2) (
4) The tape (not shown) often breaks near the tip.
Small scratches and cracks occur at part a of the mold match line (3) of the panel (1). This is because strong tension is applied to the explosion-proof metal ring (2) (for example, 30 to 36 kg/
mm'), part a of the mold match line where the tip (4a) of the joint part (4) is curved back and has a protruding shape.
The stress is concentrated at part a and applied to the panel glass, resulting in the glass crank. This phenomenon is more likely to occur as the pipe becomes larger.

To solve this problem, there is a method of elongating the joint part (4) to reduce the amount of warpage of the tip (4a) to avoid stress concentration. However, this method is not reliable enough.

Another method is to butt both ends of the strip as shown in Figure 8, place the auxiliary plate (6) on top of it, and spot weld (
5) A possible method is to form an explosion-proof metal ring band (2) and fit this metal ring band (2) to the outer periphery of the panel. However, this method is expensive in terms of workability and material costs. In addition, the number of welding points is doubled, making it difficult to ensure the reliability of the welded portion (fg contact strength).

In view of the above-mentioned points, the present invention has been developed to prevent scratches caused by explosion-proof metal rings.
This prevents the occurrence of cranks and provides a highly reliable cathode ray tube.

[Means for solving problems]

The present invention involves overlapping the end portions of the band-shaped body and connecting the joint portion (4
) with spot welding (5) and an explosion-proof metal ring (11).
), mold match line (3) by shrink fitting method.
In a cathode ray tube that is fitted around the outer periphery of a glass panel (1) so as to cover the outer periphery of the glass panel (1), the tip (4a) of the joint (4) of the explosion-proof metal ring (11) is the mold mating line. (3) and the part that comes in contact with it as a metal ring (11)
Cut out a predetermined length D along the longitudinal direction of the
12). This cut out part (12) creates a joint part (4).
) is divided into two parts (13a) and (13b) by sandwiching the mold match line (3) at the end (4a) on the side that contacts the panel ill.

In addition, in the joint part (4), the end part (14) that has been retreated by the cutout part (12) has an inclined surface (15) whose surface in contact with the panel glass gradually moves away from the panel toward the tip.
). The length D of the cut portion (12) is determined by the amount of protrusion of the mold match line, and the greater the amount of protrusion, the greater the length D to be cut out.

[Effect]

In the explosion-proof metal ring band (11), the part corresponding to the mold match line at the tip fm (4a) of the joint part (4) is cut off, and the two halves of the part (13a) and (13
b) first contacts the panel (1) in so-called multi-area contact with the panel (1). Therefore, the stress from the tip of the metal ring band is dispersed, and stress concentration at part a of the mold match line (3) is eliminated. Also, the end (
14), the side in contact with the panel (11) is an inclined surface (15), so even if the tip is warped, it will avoid or weaken the mold match line (3).As a result, the explosion-proof metal Panel (1) with ring (11)
) scratches and occurrence of cranks are avoided.

〔Example〕

Hereinafter, an example of a cathode ray tube according to the present invention will be described with reference to the drawings.

In FIG. 1, OQ) indicates a cathode ray tube body, and (11) indicates an explosion-proof metal ring that is shrink-fitted to the outer periphery of the glass panel +11 so as to cover the mold match line (3). The metal ring band (11) is constructed by overlapping the ends of band-like bodies and spot welding (5) the joints (4) at four locations. In particular, in the present invention, FIGS.
As shown in the figure, at the joint part (4) of the metal ring band (11), the end of the joint part (4a) on the side that contacts the panel (1)
Then, a portion corresponding to the mold match line (3) and its vicinity is cut out to a predetermined length D along the longitudinal direction of the metal ring band (11) to form a cutout portion (12). Furthermore, the end (14) that has retreated at the cutout (12) is gradually moved toward the panel +11 so that the surface in contact with the panel +11 moves toward the tip.
For example, it is formed by press working so as to form an inclined surface (15) that separates from 11.

In addition, on the side of the metal ring (11) in contact with the panel (1), a groove (16) may be formed in a portion corresponding to the mold match line, if necessary.

According to this configuration, in the explosion-proof metal ring band (11), the mold match line (3
) By providing the cutout portion (12) at the portion corresponding to the joint portion (4), strong tension is applied to the metal ring band (11), causing
Even if a) is warped, it will not come into point contact with the protrusion of the mold match line (3). In this case, both parts (13a) and (13b) divided into two by the cutout part (12) are panel f.
Since it is in line contact or surface contact with ll, the load on the panel is distributed in these parts (13a) and (13b),
Concentrated loads on the panel (1) are prevented. In addition, since the surface of the edge (14) that has retreated at the cutout (12) toward the panel is an inclined surface (15), this tip will not come into point contact with the panel mold match line, and even if it does, it will not come into contact with the panel mold match line. Since it is far from the tips of both parts (13a) and (13b), the amount of warpage is small and only a weak load is applied. Since concentrated loads are thus prevented, scratches or cracks on the panel (1) are avoided.

〔Effect of the invention〕

According to the present invention, in the explosion-proof metal ring that is fitted by shrink fitting to the outer periphery of the panel of the cathode ray tube, the portion corresponding to the mold match line at the tip of the joint is cut out, so that concentration on the panel is reduced. Loads are avoided and do not cause scratches or cranks on the panel. Therefore, a highly reliable cathode ray tube can be obtained.

In particular, the present invention is suitable for application to large pipes in which the amount of protrusion of the mold match line is large.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an example of a cathode ray tube according to the present invention, Fig. 2 is a plan view showing a main part of the explosion-proof metal ring, and Fig. 3 is a plan view showing the explosion-proof metal ring fitted to the panel. 4 is a perspective view of an explosion-proof metal ring; FIG. 5 is a sectional view of the main part of a cathode ray tube used for explaining the present invention; and FIG. 6 is a conventional explosion-proof metal ring. Fig. 7 is a sectional view of the main part of the explosion-proof metal ring fitted to the panel, and Fig. 8 is a sectional view showing another example of the conventional explosion-proof metal ring. be. (1) is a panel, f2) (11) is an explosion-proof metal ring,
(3) is the mold match line, (4) is the joint, (5
) is a spot weld, and (12) is a cutout.

Claims (1)

[Claims] In a cathode ray tube to which an explosion-proof metal ring is fitted including the mode match line of the panel, a portion of the explosion-proof metal ring that corresponds to the mold match line and its vicinity at the tip of the joint part of the explosion-proof metal ring is provided. A cathode ray tube that has been removed.