JPS623539B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of sealing two objects using a low melting point glass mixture as a bonding agent on one surface when the two surfaces are hermetically bonded.

For example, when manufacturing a cathode ray tube, a funnel portion and a panel portion are bonded and sealed using a slimy low melting point glass mixture (hereinafter referred to as mixture). That is, as shown in Figure 1,
Mixture 3 is applied onto the sealed end surface 2 of funnel 1, which is one of the members to be sealed, and dried by heating at, for example, 130 DEG C. for 5 to 15 minutes. This mixer 3 forms a vehicle in which, for example, 1 part of nitrocellulose or ethylcellulose is dissolved in 99 parts of an organic solvent such as amyl isoacetate or butyl isoacetate or butyl carbitol acetate, and passes 200 meshes through this vehicle. Low melting point glass (hereinafter referred to as fritted glass)
10 parts of powder was added and the mixture was thoroughly kneaded to form a slurry. Next, the sealed end surface 2 of the funnel 1
and the sealing end surface 5 of the panel 4 as the other member to be sealed are placed opposite to each other with three layers of mixer interposed therebetween, and first heated at, for example, 400° C. for one hour to form the third layer of mixer.
An organic viscosity imparting agent such as nitrocellulose in the layer is dispersed and volatilized. Next, the frit glass remaining in the mixture layer 3 is crystallized at 400 to 450°C, or in some cases, it is melted in an amorphous state, cooled, and the funnel 1 and panel 4 are sealed together, and the outside of the cathode ray tube is sealed. Get a container.

Make the mixture relatively thick, e.g. 0.5~
When applying 1.5 mm, the specific gravity of the mixture is large, for example, d: 4 to 6, so conventionally a method has been used in which the sealing end surface 2 of the funnel 1 is turned upward and the mixture discharged from the applicator is allowed to fall. However, according to such a method, as shown in FIG. 2, a dent is likely to occur in the center of the mixer 3 after drying.

If there is such a recess, when the panel 4 is superimposed on the funnel 1, a space will be created in the recess. Therefore, if the frit glass in the mixer is melted and sealed in this state, most of the air in the space will escape, but there will be a portion where it cannot escape, forming a cavity in the bonding layer. Furthermore, if the tube is cooled while the air is still escaping, a communication hole may be created that communicates the inside and outside of the cathode ray tube, or a portion where the bonding layer exists only at the inner or outer end of the cathode ray tube is likely to occur. If such a part exists, the vacuum seal of the cathode ray tube may be destroyed from that part.
In addition, the effective width of the glass bonding layer is significantly reduced in that area, resulting in a decrease in voltage resistance.
The heat accompanying the discharge generated by the voltage applied to the inner and outer surfaces of the cathode ray tube also destroys the vacuum seal and destroys the cathode ray tube.

A conceivable method to improve this drawback is to supply the mixture from below with the sealed end surface 2 of the funnel 1 facing downward. According to such a method, the mixture layer is on the lower side, and the mixture layer has a large and heavy specific gravity, for example, d: 4 to 6, as described above, so the degree of curvature of the surface becomes large, and after drying, the mixture layer is heavy. The surface is also protruding, so there is no dent as mentioned above.
It is possible to obtain good results.

However, even this method is limited by the physical characteristics of the mixture used. For example, if the viscosity of the mixture is too low, a mountain-shaped protrusion is formed on the surface of the mixture 3 as shown in FIG. In such a state, during sealing, the accuracy of regulating the position with the panel may be hindered, or areas with a large amount of mixture may protrude in large quantities, and areas with a small amount of mixture may become unfilled, causing vacuum breakdown.

SUMMARY OF THE INVENTION The object of the invention is to provide a method for sealing two objects, which makes it possible to form a relatively flat coating of a low-melting glass mixture, thereby eliminating the drawbacks mentioned above.

In the present invention, the surface to which the low-melting glass mixture is to be applied, such as the sealed end face of the funnel of a cathode ray tube, faces downward, the mixture is applied from below to this surface, and the mixture is turned over within a predetermined period of time. This is based on the knowledge that by oriented the applied surface upward, a relatively flat layer of the mixture can be obtained even after drying.

The present invention is particularly effective in sealing when at least one of the sealed end surfaces of two objects forms a circumference with the entire sealed end surface, such as sealing a funnel and a panel of a cathode ray tube.

Hereinafter, one embodiment of the present invention will be explained with reference to FIGS. 4 and 5 in the case of manufacturing a cathode ray tube.

11 is a coating device, and this coating device 11 has a container 12 that is long in the horizontal direction. This case 12
consists of a bottom plate 13, long side plates 14 on the front and rear surfaces, and short end plates 15 on both end surfaces, and further has an upper cover plate 16 attached to the front and rear of the upper surface, and the upper cover plate 1 on the front and rear sides.
An opening 17 is formed between the holes 6 and 6.

A coating mechanism 21 is provided within the container 12. In this application mechanism 21, a rotating shaft 22 is rotatably supported between end plates 15 at both ends of a container 12, and a roller 23 made of stainless steel, rubber, etc. is fixed to this rotating shaft 22. ,
It protrudes slightly from the opening 17 on the top surface of the container 12. A driving gear 24 is fixed to a protrusion at one end of the rotating shaft 22.
A drive device (not shown) is connected to the rotating shaft 22.
At the same time, the roller 23 is rotated. Further, a thickness regulating piece 25 is attached to the inner side of the side plate 14 on the front side of the container 12 with respect to the circumferential surface of the roller 23 via a support mechanism 26 so as to be freely adjustable forward and backward. A residue scraping piece 27 is attached to the inner side of the circumferential surface of the roller 23 via a support mechanism 28 so as to be adjustable in forward and backward movement.

A transfer device 31 is disposed above the coating device 11. In this transfer device 31, suspension devices 33 are movably provided on a rail 32 at predetermined intervals. Further, a support stand 34 is provided below the rail 32 up to the coating device 11 section.

Then, a low melting point glass mixture (hereinafter referred to as mixture) 3 is placed in the container 12 of the coating device 11.
The injection is carried out so that the lower part of the roller 23 is submerged and in contact with it.

When the roller 23 is rotated in the direction of the arrow, the mixer 3 adheres to the roller 23 and is drawn up, rising. Thickness regulating piece 25
The mixture film _3a is scraped off at the tip of the roller 23 so that the mixture film 3a has a desired thickness, and the amount of the mixture film _3a that adheres to the roller 23 and moves upward is controlled.

On the other hand, one of the funnels 1 as a member to be sealed is held in each suspension device 33 of the transfer device 31 with its neck portion and suspended with the sealed end surface 2 facing downward. It moves along the rail 32 in the direction of the arrow along the support stand 34.
The sealed end surface 2 of the funnel 1 has a shape in which the entire sealed end surface forms a circumference.

When the funnel 1 comes onto the roller 23 coated with the mixer film 3 _a , its sealed end surface 2 comes into contact with the mixer film 3 _a , and the mixer film 3 _a adheres to the sealed end surface 2. in this case,
It is preferable to set the sealing end surface 2 of the funnel 1 at a position slightly above the upper outer circumferential surface of the roller 23 so that it bites into the mixer film 3 _a by about 0.05 to 0.5 mm.

Then, due to the rotation of the roller 23, the roller 23
The excess mixture dust 3 adhering to the container 12 is removed by the residue scraping piece 27, merges with the mixture dust 3 inside the container 12, and is moved up again by the roller 23.

In this way, after applying the mixture 3 with the sealed end surface 2 of the funnel 1 facing downward, within the time that the applied mixture 3 does not dry,
The funnel 1 is turned over so that the sealed end surface 2 faces upward. As a result, the protruding portion of the mixer 3 that comes out in a downward state is lowered by its own weight and surface tension, sinks into the nearby mixer layer, and becomes flush with the protrusion. The surface of the low melting point glass (fritted glass) after drying has little curvature and becomes nearly flat as shown in FIG.

The reversing mechanism for reversing the funnel 1 may be any known means. For example, a mechanical or suction type chuck is attached to a rotating member such as an arm, and the chuck applies Mixture 3 and transports it to a predetermined position, chucks the funnel 1, and removes it from the suspension device 33 to rotate the rotating member. The reversing mechanism for rotating the funnel 1 held in the chuck by 180 degrees and reversing the funnel 1 so that the sealed end surface 2 faces upward may be any known means. For example, a mechanical or suction type chuck is attached to a rotating member such as an arm, and this chuck chucks the funnel 1 coated with the mixture 3 and transferred to a predetermined position, and also the suspension device 33.
The funnel 1 held in the chuck is rotated 180 degrees by the rotation of the rotating member, so that the sealed end surface 2 faces upward.

After applying Mixture 3 and drying it in the same way as before, apply it to the sealed end surface 2 of funnel 1.
Panel 4 which is the other member to be sealed facing this
The sealed end surfaces 5 of are joined via the mixer 3,
It is heated and sealed, and is formed into a cathode ray tube envelope through a cooling process. Sealed end surface 5 of the above panel 4
is a shape in which the entire sealed end surface forms a periphery.

In the above method, it is preferable to reverse the funnel mixture at a relatively early stage after application, but the time required to start reversal is determined by the physical properties of the mixture, its thickness, the width of the applied area, etc.

That is, the time from when the mixture is applied until the beginning of the inversion is preferably carried out when the mixture has stopped dripping. If the viscosity of the mixture is low, some of the mixture will drip like rain immediately after application, and if the viscosity is high, it will drip while pulling strings, and if the mixture is reversed in this state, the mixture will drip inside and outside the funnel. for example,
Consists of 0.066% nitrocellulose, 7.33% butyl acetate and 92.6% fritted glass powder, viscosity
For a mixture of 7000 centipoise, it is appropriate to apply the mixture for about 5 seconds. In addition, with mixtures that dry quickly using ethyl acetate, etc., if it takes a long time to turn over, the surface layer of the mixture will dry out, and even if it is turned over, the effect of absorbing protrusions will be small, so it is recommended to turn over a little faster. Good.

In addition, the faster the reversal speed of the funnel, the better, but if it is too fast, the mixture may be blown away or shifted to one side by the centrifugal force during reversal, so it should be adjusted according to the shape of the funnel, the characteristics of the mixture, etc. decide. For example, when the viscosity of the mixer is 7000 centipoise, the thickness is 0.8 mm, and the coating width is 8 mm, and the radius of rotation of the rotating mixer part is 40 cm or less, approximately 0.5 to 1.5 seconds is appropriate. In addition, in order to avoid applying large acceleration to the mixer, it is preferable to set the speed at the beginning and end of the rotation to be low, and to set the speed at the middle to high speed. and,
It is preferable to set the center of rotation at the time of reversal toward the mixer, that is, toward the sealed end surface of the funnel.

In addition, in implementation, the rotational speed of the roller 23 is its circumferential speed, more precisely, the circumferential speed of the mixer at the position corresponding to the sealed end surface 2 of the funnel 1 is
By setting the feeding speed to be the same as that of the funnel 1, the thickness of the mixture applied to the sealed end surface 2 of the funnel 1 can be made most uniform.

In addition, even if the thickness regulating piece 25 in the coating mechanism 21 is not used, the viscosity of the mixture can be adjusted.
Although it is possible to pump up a certain amount of mixture by regulating the outer diameter, rotational speed, etc., it is possible to make it even more uniform by using the thickness regulating piece 25.

Furthermore, although it is possible to apply the coating without using the scraping piece 27, if the operation is continued for a long time, a hard-to-move mixture layer will remain on the surface of the roller 23 and will be applied to the sealed end surface 2 of the funnel 1. Its use is desirable because it reduces the amount of mixture and causes local variations in thickness. Further, by providing an angle at the end opposite to the roller 23, that is, the end where the mixer falls, the air bubbles can be pushed out and defoamed there.

In each of the above-mentioned embodiments, a cathode ray tube, that is, a funnel and a panel are sealed with a mixer. It can be widely used in the manufacture of articles such as glass tubes and bulbs, such as when sealing a cover glass having a shape that forms a glass tube with a mixer.

According to the present invention, a low melting point glass mixture (mixture) is supplied and applied from below to the sealed end face of one of the members to be sealed, such as a funnel, in a downward state, and before the applied mixture has dried, it is applied to one side. By inverting the member to be sealed so that the sealed end surface, that is, the coated mixture is facing upward, the protrusions of the mixture are absorbed by the mixture's own weight and surface tension, and the mixture can be applied evenly. can. Therefore, sealing with the other member to be sealed can be performed reliably.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a funnel and panel of a cathode ray tube, FIGS. 2 and 3 are sectional views showing a conventional application state, FIG. 4 is a sectional view of an apparatus showing an embodiment of the present invention, and FIG. 5 6 is a partially cutaway perspective view, and FIG. 6 is a cross-sectional view showing a state in which the method of the present invention is in progress. 1...Funnel as one member to be sealed,
2...Sealed end surface, 3...Low melting point glass mixture, 4
. . . Panel as the other member to be sealed, 5 . . . Sealing end surface.

Claims (1)

[Claims] 1. A low melting point glass mixture is poured from below with the sealed end face of one of the members to be sealed facing downward, and the mixture is turned over within a time period before it dries to cover the sealed end face. A method for sealing two objects, characterized in that the two objects are oriented upward, and then the sealed end surface of this member to be sealed is joined to the sealed end surface of another member to be sealed. 2. The method of sealing two objects according to claim 1, characterized in that the sealed end face of the one member to be sealed forms a periphery with the entire sealed end face.