JPH0644460B2 - Explosion-proof CRT - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an explosion-proof type cathode ray tube in which a belt frame is attached to a side wall portion of a cathode ray tube and a tightening force is applied to the side wall portion.

[Conventional technology]

FIG. 4 is a plan view showing an explosion-proof type cathode ray tube which has been conventionally and conventionally used. In the figure, (1) is a cathode ray tube, (1a) is a side wall portion of the cathode ray tube, and (3) is a band frame disposed outside the side wall portion (1a) by shrink fitting.

Conventionally, as a measure to prevent the implosion of the cathode ray tube (1), a so-called shrink method has been adopted, in which a panel frame side wall (1a) of the cathode ray tube (1) is shrink-fitted (for example, Japanese Patent Publication No. 54-22864). Gazette). This cathode ray tube is first stretched by heating a thin steel band frame (3) of uniform thickness having an inner peripheral length slightly shorter than the side wall peripheral length of the panel and fitted into the side wall portion of the cathode ray tube. It is manufactured so that a tightening force is applied to the panel side wall portion (1a) when the strip frame (3) returns to room temperature.

[Problems to be solved by the invention]

In the conventional explosion-proof type cathode ray tube, the tightening force of the band frame is concentrated on the four corners of the cathode ray tube, and the force exerted on the side wall becomes small, so that there is a problem that the explosion-proof performance cannot be sufficiently exhibited.

The present invention is made to eliminate the problem that the tightening force is biased as described above. By applying a part of the tightening force to the side wall as pressure, an explosion-proof type cathode-ray tube with improved explosion-proof performance is provided. The purpose is to provide.

[Means for solving problems]

The explosion-proof cathode ray tube of the present invention is such that an annular band frame for fastening the side wall portion is shrink-fitted to the side wall portion of the cathode ray tube.
This strip frame is composed of two layers of metal, an inner strip frame and an outer strip frame having a coefficient of thermal expansion larger than that of the inner strip frame, and each side portion of the strip frame is convex inward toward the side wall of the cathode ray tube. In addition to the above, the inner or outer band frame is formed with a groove in the longitudinal direction thereof.

[Action]

The band frame according to the present invention is composed of two layers of an inner band frame and an outer band frame having a large coefficient of thermal expansion, and each side is formed so as to project inward inward with respect to the side wall of the cathode ray tube. As a result, pressure is exerted on the side wall of the cathode ray tube, and the explosion-proof performance can be improved.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. First
FIG. 2 is a sectional view showing a band frame according to this embodiment, and FIG. 2 is a plan view showing the shape before shrink fitting. In the figure,
(2) is a strip frame, (2a) is an inner strip frame made of, for example, steel, (2
b) is an outer band frame having a larger coefficient of thermal expansion than the inner band frame (2a), and is made of, for example, copper.
c) is formed. The inner and outer band frames (2a) and (2b) are molded as a one-piece band frame (2) by joining them by an appropriate means, and the length is set to be slightly shorter than the peripheral portion of the cathode ray tube. Has been done. Further, as shown in FIG. 2, the belt frame (2) is used for the inner and outer belt frames (2a) and (2b) respectively, or the inner and outer belt frames (2a) and (2b) are integrated. When it is molded as a product, it is processed so as to have a convex shape inward toward the side wall portion (1a) side of the cathode ray tube.

By arranging the band frame (2) thus formed on the cathode ray tube side wall portion (1a) by shrink fitting and then cooling, the shrink type explosion proof cathode ray tube of this embodiment can be obtained.

In the explosion-proof type cathode-ray tube of this embodiment, the band frame (2) that is convex inward with respect to the side wall portion (1a) of the cathode-ray tube before shrink fitting, the coefficient of thermal expansion of the outer band frame (2b). Since it is larger than the inner band frame (2a), the increase in the size of the outer band frame (2b) due to the heating at the time of shrink fitting increases the curvature of the edge (side) of the band frame (2) after heating. The decrease or, on the contrary, the convex in the outer direction facilitates the arrangement on the side wall (1a) of the cathode ray tube.

At the time of cooling after shrink fitting, the entire band frame shrinks and exerts a tightening force on the four corners of the cathode ray tube as in the conventional example, and the shrinkage amount of the outer band frame (2b) is reduced for the same reason as during heating. Since the inner frame (2a) is larger than the inner frame (2a), the overall shape of the frame (2) tries to return to the shape shown in Fig. 2, so that pressure is exerted on the side wall (1a) of the cathode ray tube to prevent explosion. Improve performance.

Further, since a groove is provided in the longitudinal direction on the outer peripheral side of the outer frame (2b), warpage in the cross section of the band frame (2) at the time of heating and contraction, that is, bending in the width direction is prevented. Is possible,
The inner peripheral surface of the inner band frame comes into close contact with the side wall of the CRT.

In the above embodiment, the case where a plurality of grooves (2c) parallel to the outer peripheral side longitudinal direction of the outer band frame (2b) are provided is described, but the groove (2c)
There can be only one. Further, the outer band frame (2b) does not have to be a single member, and as shown in the sectional view of FIG.
(a) a plurality of outer band frames (2b) arranged with a gap formed as a unit, that is, a plurality of grooves (2c) reaching the inner band frame (2a) to the outer band frame (2b) The same effect can be obtained even if the shape is cut out.

Further, in the above embodiment, the groove (2c) is provided in the outer band frame (2b) in order to secure a sufficient tightening force by shrink fitting, but it may be provided in the inner band frame (2a).

〔The invention's effect〕

As described above, according to the present invention, the annular band frame for tightening the side wall part is shrink-fitted to the side wall part of the cathode ray tube, and this band frame is the outer band having a larger thermal expansion coefficient than the inner band frame and the inner band frame. It is composed of two layers of metal of the band frame, and each side part of the band frame is formed so as to be convex inward with respect to the side wall of the cathode ray tube, and a groove is formed in the inner or outer band frame in the longitudinal direction. By forming it, it is possible to apply pressure not only to the four corners but also to the side wall of the cathode ray tube, and there is an effect that an explosion proof type cathode ray tube with high explosion proof performance can be obtained.

[Brief description of drawings]

1 is a sectional view showing a band frame before shrink fitting according to an embodiment of the present invention, FIG. 2 is a plan view thereof, FIG. 3 is a sectional view showing a band frame according to another embodiment, and FIG. FIG. 1 is a plan view showing a conventional explosion-proof cathode ray tube. In the figure, (1) is a cathode ray tube, (1a) is a cathode ray tube side wall, (2) is a band frame, (2a) is an inner band frame, (2b) is an outer band frame, and (2c) is a groove. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (3)

[Claims] 1. A two-layer structure comprising an inner band frame and an outer band frame having a thermal expansion coefficient higher than that of the inner band frame, wherein an annular band frame for fastening the side wall part is shrink-fitted to the side wall part of the cathode ray tube. And each side is formed so as to be convex inward with respect to the side wall of the cathode ray tube and a groove is formed in the longitudinal direction of the inner or outer band frame. Explosion-proof cathode ray tube. 2. The explosion-proof cathode ray tube according to claim 1, wherein the groove is cut out to the boundary surface of the inner and outer band frames. 3. The band frame according to claim 2, wherein the band frame is formed by joining a plurality of outer (or inner) frame frames to the inner (or outer) band frame with groove separation. Explosion-proof CRT.