KR100837241B1 - Funnel for cathode ray tube - Google Patents

Abstract

The present invention discloses a funnel for cathode ray tube which improves the shape of the freeland land provided for press molding. The funnel of the present invention has a free seal land forming an end of the cutting margin, which is provided to be formed by polishing the seal edge of the body portion joined to the seal edge of the panel during press molding. Further, a protruding portion protruding from an outer side of the slack land adjacent to the outer surface of the body portion is formed inside the slack land close to the inner surface of the body portion, and a flat portion is formed on the outer side of the slack land. According to the present invention, by improving the shape of the slack land so that the inner side of the slack land formed by the cutting margin applied during the press forming of the funnel protrudes from the outer side, it is possible to effectively prevent the occurrence of defects due to thermal shock in the slow cooling process. Can be. In addition, in the polishing process for polishing the cutting margin to form the seal edge of the funnel, by greatly reducing the amount of polishing to improve the efficiency of the polishing process, it is possible to improve the productivity and reduce the production cost.

Description

Funnel for cathode ray tube {FUNNEL FOR CATHODE RAY TUBE}

1 is a cross-sectional view showing the configuration of a glass bulb for a typical cathode ray tube as an example;

FIG. 2 is a cross-sectional view partially showing a seal edge of a panel and a funnel in the glass bulb of FIG. 1;

3 is a partially enlarged cross-sectional view showing a seal edge of a conventional cathode ray funnel;

4 is a partially enlarged cross-sectional view showing a seal edge of a cathode ray tube funnel according to the present invention.

♣ Explanation of symbols for the main parts of the drawing ♣

20: Panel 21: Thread Edge

30: Funnel 31: Threaded

41: glass powder 42: sealing pool

70: cutting allowance 71: free sealant

72: projection 73: plane

74: slope 80: ring mold

81: cutting groove 82: upper mold

The present invention relates to a funnel for cathode ray tubes, and more particularly, to a funnel for cathode ray tubes in which the shape of a free sealant provided for press molding of the funnel is improved.

As is well known, glass bulbs used in the manufacture of color televisions, computer monitors, etc. are basically three components: a panel through which images are projected, and a rear surface of the panel. Conical funnels are joined and tubular necks fused to the vertices of the funnels. Panels, funnels and necks are all made of glass, and in particular panels and funnels are produced by press molding a molten glass mass called glass gob to a desired size and shape.

An example of a glass bulb for a typical cathode ray tube will be described with reference to FIGS. 1 and 2. The panel 20 of the glass bulb 10 has a face portion 21 on which an image forming phosphor is coated on an inner surface thereof to display an image. And a skirt portion 23 having a seal edge 22 extending rearward from the edge of the face portion 21, and connecting the face portion 21 and the skirt portion 23 to each other. It is composed of a blend round portion (24). The funnel 30 has a body portion 32 having a thread edge 31 bonded to the thread edge 22 of the panel 20, and a yoke portion extending behind the body portion 32. portion 33). The neck 40 is joined to the yoke portion 33 of the funnel 30.

As shown in detail in FIG. 2, the yarn edge 22 of the panel 20 and the yarn edge 31 of the funnel 30 are joined by crystalline powder glass 41 called frit. . Sealing pools for penetration of the powder glass 41 at the interface of the seal edges 22 and 31 on the inner surfaces 20a and 30a and the outer surfaces 20b and 30b of the panel 20 and the funnel 30, respectively. Inner inclined surfaces 43a and 44a and outer inclined surfaces 43b and 44b forming a sealing pool 42 are formed.

Meanwhile, a mold set for forming the cathode ray tube funnel 30 is combined with a bottom mold for forming the body portion 32 of the funnel 30 and a bottom mold to form the funnel 30. The yoke mold for forming the yoke portion 33, an upper mold called a plunger for pressing and forming a glass product supplied to the lower mold, and an upper mold and a ring adapter It is coupled and consists of a ring mold (Ring mold) for forming the seal edge 31 of the funnel (30).

The upper mold of the mold set is installed in the ram of the press, and is formed by the funnel 30 by pressing the glass product supplied to the lower mold while lifting and lowering by the operation of the ram. After the press molding, the funnel 30 is taken out from the lower mold and subjected to a pin sealing process of the stud pin in a naturally cooled state, and is manufactured as a finished product through a slow cooling process in an annealing lehr, a polishing and an inspection process. Since the panel generally has a rough surface when it comes out of the molding process, in order to improve the image quality of the cathode ray tube, the surface of the panel is properly polished to remove optical defects, and the panel 20 and the funnel 30 For the sake of accurate bonding, the yarn edges 22 of the panel 20 and the yarn edges 31 of the funnel 30 are polished, respectively.

As shown in FIG. 3, the conventional funnel for funnel tube has an accurate design of the seal edge 31 of the funnel 30 bonded to the seal edge 22 of the panel 20 during press molding of the funnel 30. In order to grind to a dimension, the finishing allowance 50 is set to a predetermined height from the thread edge 31 represented by an imaginary line. However, the funnel 30 is supplied to the mesh belt of the slow cooling furnace in a state in which the thread edge 31 is downwardly downward in the thread edge, and thus, the funnel 30 has a margin for forming the end of the cutting margin 50 in contact with the mesh belt. As the area of the seal land 51 is increased, there is a problem in that defects such as fine cracks and cracks are generated in the free seal land 51.

In order to prevent the defect of the free land (50) generated in the slow cooling process, a groove (Groove: 61) is formed on the bottom surface of the ring mold 60 to form a ball-type groove at approximately the center of the free land (51). A semicircular projection 52 called a ball type groove is formed. However, as the cutting margin 50 is increased due to the formation of the projections 52, the amount of polishing is also increased to decrease productivity. Glass powder and abrasives generated after grinding not only impair the working environment, but also contaminate the air and water, so special care must be taken when disposing, which increases the disposal cost.

In addition, between the inner bottom end of the ring mold 60 and the outer surface of the upper mold 62, there is a difference in the filling rate of the glass product filled in the cavity of the lower mold according to the pressure of the upper mold 62. Groove lap is generated in the area A indicated by the hidden line of. Groove wrap is mainly generated in the shorter direction than the long axis and the diagonal axis direction of the funnel 30, the groove wrap needs to be removed completely by polishing. However, in addition to the removal of the protrusions 52, there is a problem that the amount of polishing must be increased for the removal of the additional grooves, and when the amount of the polishing is reduced, the grooves are left.

The present invention has been made to solve the various problems of the prior art as described above, the object of the present invention is to improve the shape of the slack land provided for the press molding of the funnel, the defects due to thermal shock in the slow cooling process It is to provide a funnel for a cathode ray tube that can effectively prevent the occurrence of.

Another object of the present invention is to provide a funnel for cathode ray tubes that can greatly reduce the amount of polishing and improve the efficiency of the polishing process, thereby improving productivity and reducing production costs.

A feature of the present invention for achieving the above object, for the cathode ray tube having a free seal land forming the end of the cutting margin is provided to be formed by polishing the seal edge of the body portion bonded to the seal edge of the panel during press molding In the funnel, the inner side of the slack land close to the inner surface of the body portion is formed with a protruding portion protruding from the outer side of the slack land close to the outer surface of the body portion, the outer side of the slack land funnel for cathode ray tubes formed with a flat portion formed. Is in.

Hereinafter, a preferred embodiment of a cathode ray tube funnel according to the present invention will be described in detail with reference to the accompanying drawings, the basic configuration of the glass bulb for the cathode ray tube described in Figures 1 and 2 will be described with the same reference numerals.

First, referring to Figures 2 and 4 together, the funnel 30 of the present invention forms the end of the cutting margin 70 given at a predetermined height from the yarn edge 31 represented by a virtual line for polishing during press molding. The inner side of the slack land 71 having the slack land 71 and adjacent to the inner surface 30a of the body portion 32 of the funnel 30 is closer than the outer side closer to the outer surface 30b of the body portion 32. It protrudes. That is, the protrusion 72 is connected to the inner inclined surface 44a on the inner side of the clearance land 71 and the flat portion 73 is connected to the outer inclined surface 44b on the outer side.

In addition, the protrusion part 72 and the planar part 73 of the clearance land 71 are connected by the inclined surface 74. The protruding portion 72 and the inclined surface 74 are connected by the first round portion 75a, and the flat portion 73 and the inclined surface 74 are connected by the second round portion 75b. It is possible to reduce the amount of polishing so that forming the width of the protruding portion 72 smaller than the width of the flat portion 73 is advantageous for polishing. For example, the width of the protruding portion 72 is formed to have an occupancy ratio of about 10 to 30% based on the width of the free seal land 71, and the width of the flat portion 73 has an occupancy ratio of about 50 to 80%. It is preferable to form.

As shown in FIG. 4, in order to form the protruding portion 72, a cutout groove 81 corresponding to the shape of the protruding portion 72 is formed inside the lower surface of the ring mold 80. In press molding of the funnel 30, when the glass product supplied to the cavity of the lower mold is pressed by the ring mold 80 and the upper mold 82, the glass product is subjected to the molding pressure of the upper mold 82. It is filled in the cavity. At this time, there is a deviation in the supply amount of the glass product supplied to the cavity of the lower mold, and when the supply is insufficient, the molding failure of the free seal 71 may occur due to the lack of filling of the glass product.

On the other hand, the cutting margin 70 of the funnel (30) serves to give a margin to the supply amount of the glass product to prevent the unmolding of the free seal land 71 due to the lack of filling. And the cutting groove 81 of the ring mold 80 for forming the protrusion 72 of the slack land 71 serves as a slack cavity that can accommodate the excess glass product when the supply amount of the glass product is excessive. Do it. By providing the cutting margin 70 and forming the protrusion 72, a sufficient amount of rational product required for press molding of the funnel 30 can be supplied. Molding failure of the land 71 can be effectively prevented.

In addition, the groove B shown by the hidden line of FIG. 4 is a groove lap generated by a difference in the rate at which the ratio of the product is filled between the inner bottom end of the ring mold 80 and the outer surface of the upper mold 82 during press molding. ), Ie, the protrusions 72 removed in the polishing process. Therefore, in the polishing process, the groove wrap may be completely removed by only the polishing amount capable of removing the protrusion 72, and as a result, the polishing amount of the funnel 30 may be reduced to improve productivity and reduce production cost. In addition, the protrusion 72 formed inside the slack land 71 reduces the area of the slack land 71 in contact with the mesh belt of the slow cooling furnace, thereby effectively preventing defects such as gold and cracks due to thermal shock. can do.

The above embodiments are merely illustrative of preferred embodiments of the present invention, and the scope of the present invention is not limited to the described embodiments, and various modifications may be made by those skilled in the art within the spirit and scope of the present invention. Modifications, variations, or substitutions may be made, and such embodiments are to be understood as being within the scope of the present invention.

As described above, according to the cathode ray tube funnel according to the present invention, by improving the shape of the free seal land so that the inside of the free seal land formed by the cutting margin applied during the press molding of the funnel from the outside, in the slow cooling process The occurrence of defects due to thermal shock can be effectively prevented. In addition, in the polishing process for polishing the cutting margin to form the seal edge of the funnel, by greatly reducing the amount of polishing to improve the efficiency of the polishing process, it is possible to improve the productivity and reduce the production cost.

Claims (3)

In the funnel for cathode ray tube having a free seal land forming the end of the cutting margin is provided so that the seal edge of the body portion bonded to the seal edge of the panel during polishing may be formed by polishing, A protruding portion protruding from an outer side of the slack land adjacent to the outer surface of the body portion is formed inside the slack land adjacent to the inner surface of the body part, and a flat portion is formed on the outer side of the slack seal land. Funnel for cathode ray tubes. The funnel for cathode ray tubes according to claim 1, wherein the protruding portion and the flat portion are connected by an inclined surface. The funnel for cathode ray tubes according to claim 1 or 2, wherein a width of the protruding portion is smaller than a width of the flat portion.

Images