SU1095268A1 - Face for colour picture tube - Google Patents

Abstract

COLOR KINESCOPE SCREEN, containing a bottom and a closed board, on the inner side of which there are metal clamps SKu.iiiv / rMA with a cylindrical skirt, characterized in that, in order to increase the mechanical strength and thermal stability of the screen, to increase the yield of suitable products, the board with clamps is complete so that the distances along the inner side of the screen from the axis of the clamp to the end of the board and to the bottom, respectively, are no less than 2.8 and 3.2 times the outer radius of the skirt of the clamp, and the ratio of the length The styling of the retainer skirt (b) to the minimum thickness of the bead (d) is chosen from the relation § 0.4 4 0.7 (About co to o: 00 "LR. /

Description

11 The invention relates to the production of color kinescopes, in particular their screens containing metal clamps for attaching a mask. In the manufacture, testing and operation of kinescopes, a large part of the destruction of the shells occurs along the fixative assembly; therefore, a number of requirements are imposed on it, in particular, high mechanical and thermal stability, which should ensure the reliability of kinescopes. Most of the damage to the fixing unit occurs due to the occurrence of critical stresses in it during the heat treatment of shields and shells. Temperature stresses in metal spheres with glass, as this place in the fixing unit, are created for the following reasons. The first of these is the difference in the temperature of the elements of the spa (in the initial period of change in the ambient temperature) due to the existing difference in the thermophysical characteristics of glass and metal, and the second is in the temperature drop in the glass in the vicinity of the fixing unit due to the relatively small , thermal conductivity of glass is third in the difference of linear thermal expansion coefficients (CTLR) of metal and glass. Even after equalizing the temperature in the junction (fixing unit) made of materials differing in the CTLR size, deformations remain, causing thermal stresses, to which, during the operation of the opscore, pure mechanical damage is also added. Therefore, it is important to take into account that the level of these stresses depends both on the quality of welding of the retainer into the board, on the degree of compliance of the spa retainer-glass, and on the design of the retainer assembly, in particular, on the location of the retainer along the side height of the screen, i.e. from the distance between the center of the retainer and the end of the bead, the center of the retainer and the bottom of the screen, as well as the depth of its welding in the board. A known color kinescope (for example, 25LK2Ts), containing a screen with latches, the screen side of the screen being comparable with the diameter of the fixture, and the thickness of the board with the depth of the –barrel into the side G1. This imposes additional requirements (as opposed, for example, on 61LKZTS picture tubes) to the design of the locking assembly. The level of thermal stresses after welding and fixing the screen and annealing significantly depends on the location of the fixture along the side of the screen and the depth of welding. Thermal processing of screens in industrial conditions in the modes of stabilization of a frame-mask unit and soldering of the screen with a cone leads to the occurrence of a clamp with a glass of tensile stresses in junctions. The design of the 25LK2T kinescope screen leads to the fact that with small deviations of the location of the fixture in the board from the optimal level of thermal stresses during heat treatment operations can exceed the critical level, which leads to the destruction of the screen. Thus, when designing screens of color kinescopes containing clamps, it is especially important to satisfy the consistency of the materials of the latch-glass spa and to provide geometrical ratios for the placement of the latch in the bead of the screen, helping to minimize thermal stress in the locking assembly. Closest to the present invention is a kinescope screen, comprising a bottom and a closed board, on the inner side of which there are metal clamps with a cylindrical skirt. For mounting the latches, a device is used with which the latches and the glass surface areas are heated to the operating temperature, and then the latches are inserted into the t2 glass. However, this design does not take into account the effects of placing the clips on the height of the side of the screen and the depth of the skirt of the lock into the board on the level of residual stresses and non-stationary thermal stresses in the manufacture and heat treatment of the screens. As a result of this, if the latch is not optimally placed in the screen in the event of an abrupt change in the ambient temperature in the junction of the latch-glass, sufficiently large transient thermal stresses occur, leading to the destruction of the shields. 31 The aim of the invention is to increase the mechanical strength and thermal stability of screens, increasing the yield of products. This goal is achieved by the fact that in the screen of a color kinescope containing a bottom and a closed board, on the inner side of which there are metal clamps with a cylindrical skirt, the board with clamps is designed in such a way that the distance from the inner side of the screen is from the clamp axis to the end the sides and to the bottom, respectively, are no less than 2.8 and 3.2 times the outer radius of the skirt of the retainer, and the ratio of the length of the part of the retainer skirt (b) immersed in the side to the minimum thickness of the side (d) is selected from the ratio 0.4, t. d As shown by experimental studies and theoretical calculations, the most dangerous in the fixing unit are tensile annular (tangential) stresses 6iPU). For a 25LK2T screen made of C 95-3 glass with a latch made of 47НХР alloy, the maximum value of stresses is observed at 130-150 ° C. FIG. 1 shows a screen with a fixator welded into it, a section in FIG. 2 shows the dependence of the maximum annular stresses as a function of the distance of the center of the fixer from the end of the bead; FIG. 3 shows the dependence of the maximum voltage Ouiui on the distance to the bottom of the screen; FIG. 4, the dependence 6aiu) on the location of the center of the fixer along the height of the bead, FIG. 5 - curve of dependence of stresses () if on the depth of immersion of the lock into the board. FIG. Figure 1 shows the fixing unit of the color kinescope screen, consisting of the fixer 1 and the bead, the screen 2, the fixator protrudes into the external environment on the inner side of the screen. The outer radius of the skirt of the retainer is R, the depth of its insertion into the bead is b, the distance along the inner side of the screen side from the axis of the retainer to the butt end is “to the bottom — b, the thickness of the side of the screen is d. FIG. Figure 2 shows the dependence of the maximum stresses on the distance of the center of the fixer from the end of the bead. The curve is presented for case 8 when the distance from the center of the latch to the bottom of the screen is 10 times the outer radius of the skirt of the latch. When satisfying the ratio a / 1 to 2.8, the ring voltages are almost unchanged and are the smallest. FIG. Figure 3 shows the dependence of the maximum stresses as a function of the distance of the center of the fixer to the bottom of the screen. The curve is presented for the case when the distance from the center of the lock to the end of the bead is 10 times greater than the outer radius of the skirt of the lock. It can be seen from the graph that with an increase in the ratio of K1, the voltages also decrease in the case when FcfR 3.2 reaches a constant level. FIG. Figure 4 shows the curves of variation of the maximum stresses. in the case when the ratio of the screen side height to the outer radius, skirts OI-b. O-t-fa. . M-ffa .а -Б- 4; -р - () .- р-в. the latch is equal When increasing the ratio of the bead of the screen to the outer radius of the skirt of the latch, the zone of the possible location of the latch increases accordingly. In this zone, the voltages are minimal and the location of the latch center over the screen bead satisfies the relation a b, 8 i. FIG. Figure 5 shows the dependence of the maximum ring stresses depending on the depth of the avar of the skirt of the retainer into the side of the screen. With increasing depth of weld, Vi, the voltage changes dramatically until the ratio 4 is satisfied. do not change. As h (-) increases further, the stress level increases. Thus, the proposed design of the locking assembly of the screen of a compact color kinescope ensures the optimum possible thermal strength, reliability and durability of the screen of a color kinescope under environmental conditions, which significantly increases its quality, increasing the output of usable products by reducing scrap due to:. on fixative knot on thermorb processing operations.

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Claims (1)

COLOR KINESCOPE SCREEN, containing a bottom and a closed board, on the inside of which there are metal clips with a cylindrical skirt, characterized in that, in order to increase the mechanical strength and thermal stability of the screen, increase the yield of products, the board with the clips is made so that the distance along the inner side of the bead of the screen from the axis of the retainer to the end of the bead and to the bottom, respectively, not less than 2.8 and 3.2 times the outer radius of the skirt of the retainer, and the ratio of the length of the immersed in the side of the skirt of the fix torus (h) to the minimum bead thickness (d) is selected from the relation 0.4 4 -j- ί 0.7 ABOUT SB sl to Ci Fie. 1>