JP2006140099A - Glass funnel for cathode-ray tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass funnel for cathode-ray tube capable of preventing happening of a scratch on the reference face, when a jig is contacted to the reference face of a positioning reference section, and wear and tear of the tip of the jig contacted to the reference face can be suppressed. <P>SOLUTION: The glass funnel 1 for the cathode-ray tube has a positioning reference section 8 on the outer wall face of a body part 6 for positioning at the time of sealing with the cathode-ray tube glass panel. The reference face 8a of the positioning reference section 8 is same as is press molded and when the ten-point average roughness is made Rz and the average spacing of the concavo-convex is made Sm, it has a specific rough face of 3 μm≤Rz≤20 μm, and 300 μm≤Sm≤800 μm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a glass funnel for a cathode ray tube, and more particularly to a technique for improving the surface property of a positioning reference portion formed on an outer wall surface of a body portion of a glass funnel for a cathode ray tube.

  As is well known, a cathode ray tube used in a display device such as a color television receiver has, as main glass parts, a glass panel for a cathode ray tube (hereinafter also simply referred to as a panel) on which an image is projected and a glass for a substantially funnel-like cathode ray tube. A funnel (hereinafter, also simply referred to as a funnel). In this case, the panel has a substantially rectangular face portion having an effective screen for displaying an image, and four sides connected to the face portion via a blend R portion, and the skirt portion extends from these sides. In addition, a sealing end surface used for sealing with the funnel is formed at the opening end of the skirt portion.

  On the other hand, the funnel has a large opening end having a substantially rectangular sealing end surface used for sealing with a panel at one end and the other end in a direction along the tube axis, and a neck tube to which an electron gun is attached. A substantially circular small opening end used for welding is formed, and the side wall portion of the funnel having the tube axis as the central axis has a substantially funnel shape. More specifically, the side wall portion of the funnel has a body portion extending from the large opening end to a predetermined position on the small opening end side, and a yoke portion connected to the small opening end side, and is sealed at the large opening end of the body portion. The attachment end face is sealed and joined with a sealing end face at the opening end of the panel and frit glass interposed therebetween.

  By the way, in this type of cathode ray tube, phosphors (RGB (the three primary colors of red, green and blue)) and carbon are applied in a fine pattern on the inner surface of the panel. Therefore, in order to reliably irradiate such fine phosphors with electrons and display a proper image without color misregistration as a cathode ray tube, the phosphor-coated panel and the electrons It is important that the center axis of the funnel on which the neck tube equipped with the gun is welded is accurately positioned and assembled with respect to the tube axis of the cathode ray tube. Therefore, a plurality of (for example, three) positioning reference portions are provided on the outer wall surfaces of the adjacent body portions of the funnel for positioning with respect to the panel by contacting a jig when the panel is sealed. It is done. The positioning reference portion has a convex shape having a reference surface with which the jig abuts, and the reference surface is formed at a predetermined distance from the center axis of the funnel. Note that the tip of the jig that is in contact with the reference surface is made of a heat-resistant carbon material that hardly damages the funnel that is a glass member.

  As a funnel molding method, a molten glass block called gob is supplied into a receiving mold (female mold) composed of a bottom mold (bottom mold) and a trunk mold (shell mold). After the molten glass lump is formed into a predetermined shape by pressing it with a pressing die (plunger die), the plunger die and the shell die are removed and cooled sufficiently, and then the bottom die This is done by removing the funnel from the mold. In this case, the molding surface portion corresponding to the positioning reference portion is formed as a recess in the bottom mold.

  By the way, in the following Patent Document 1, the reference surface of the positioning reference portion of the funnel is polished after press molding, and the 10-point average roughness Rz of the surface and the average interval Sm of the unevenness are 0.7% ≦ Rz. It is disclosed that the relationship of / Sm ≦ 3% is satisfied. According to this, it can be expected that the wear of the jig tip made of the carbon material in contact with the reference surface is suppressed and the funnel positioning accuracy is maintained well.

  Further, in the following Patent Document 2, the surface of a bottom mold for funnel molding is frosted, and the ten-point average roughness Rz of the surface is set to 15 to 35 μm. The structure which can be transcribe | transferred from the metal mold | die to the outer wall surface of the body part of a funnel is disclosed. According to this, improvement of glass releasability, workability of press molding, and mold life can be expected. In addition, although this patent document 2 does not particularly refer to the positioning reference portion, in view of the fact that the positioning reference portion is formed at a predetermined portion of the outer wall surface of the body portion, the reference surface of the positioning reference portion is also It is presumed that surface roughness equivalent to the above numerical range is given.

Japanese Patent Laid-Open No. 9-245646 Japanese Patent Laid-Open No. 9-255349

  By the way, said patent document 1 grind | polishes a reference surface after shaping | molding a funnel, and provides the surface roughness of the said numerical range to a reference surface, In such a grinding | polishing method, rough grinding | polishing by a rough abrasive is used. A process and a finishing process with an abrasive having a fine average particle size.

  However, the surface properties of the reference surface according to such a method show a shape in which the surface is severely uneven and the interval between the protrusions is narrow in the rough polishing step with a rough abrasive. After that, it is polished with a fine abrasive to finish it to a smooth surface, but at this time, of the irregularities on the surface when polished with a coarse abrasive, the convex part is preferentially shaved. Become. That is, even if the surface is polished with a fine abrasive in the finishing step and a desired surface roughness is imparted to the reference surface, the concave portion formed when polished with the coarse abrasive remains without being polished. Moreover, the bottom of the recess has an acute angle. Such recesses are present on the reference surface as scratches, so-called polishing scratches when visible, and so-called latent scratches when not visible.

  After the funnel is aligned with the panel, the frit glass interposed between the sealing end faces is melted and sealed to each other. When the temperature of the sealing process is lowered, the funnel is sealed. In the vicinity of the end face, tensile stress is generated on the outer wall surface. And since the positioning reference | standard part of a funnel is located in the vicinity of a sealing end surface, naturally a tensile stress will arise also in a positioning reference | standard part. At this time, if there is a polishing scratch or a latent scratch as described above on the reference surface of the positioning reference portion, stress concentration occurs at the bottom of the scratch having an acute angle (recess bottom), and the funnel may be damaged. Therefore, by providing a rough surface within the above numerical range to the reference surface, even if wear at the tip of the jig is suppressed, a new problem arises in that the mechanical strength of the funnel is significantly reduced. .

  Also, if the above problem is to be avoided by performing only the finishing process using an abrasive having a fine average particle size without performing the rough polishing process using a coarse abrasive, the rough surface in the above numerical range is given to the reference surface. It takes a lot of work time to do so, and it causes unnecessarily high funnel manufacturing costs, which is not practical.

  On the other hand, as described above, the above-mentioned Patent Document 2 applies a predetermined surface roughness to a bottom mold for funnel molding in advance, and transfers the same unevenness from the mold to the body part of the funnel. is there. And, the reference surface transferred from the mold by this type of press molding is different from the polished surface, the unevenness of the surface is very gentle, the recess is sufficiently shallow with respect to its width, and The bottom of the recess is rounded due to the surface tension during glass melting. That is, even if the mold has some sharp irregularities, it is not transferred as it is to the glass surface. Moreover, since it is not necessary to polish after press molding, the funnel can be manufactured in a short time. Therefore, as described above, the problem caused by polishing the reference surface after molding cannot occur.

  However, the above-described Patent Document 2 is not made in consideration of the reference surface of the positioning reference portion as described above, and the surface roughness imparted to the reference surface tends to be somewhat rough. Moreover, since the surface roughness of the bottom mold is defined only by the 10-point average roughness Rz, even if the 10-point average roughness Rz of the reference surface to which it is transferred is appropriate, the unevenness If the average interval Sm is unreasonably large, the probability that the jig comes into contact with the concave portion of the surface irregularities transferred to the reference surface increases, and the concave portion is likely to be damaged. And when a crack arises in a recessed part, the problem of causing a malfunction, such as a failure | damage, arises by the thermal stress at the time of temperature fall in the sealing process of a funnel and a panel arises. On the other hand, if the average interval Sm between the concaves and convexes is unduly small, the tip of the jig that comes into contact with the reference surface is likely to be worn, and there is a problem in that accurate positioning of the funnel cannot be maintained.

  The present invention has been made in view of the above circumstances. By leaving the reference surface of the positioning reference portion of the glass funnel for a cathode ray tube as a press-molded surface, there is a problem caused by polishing the reference surface after press molding. In addition to avoiding it and properly determining the relationship between the ten-point average roughness Rz of the reference surface and the average spacing Sm of the irregularities, the mechanical strength of the funnel is prevented from being lowered as much as possible and the positioning accuracy is maintained well. Doing this is a technical issue.

  The present invention devised to solve the above problems has a substantially rectangular large opening end and a substantially circular small opening end at one end and the other end in the tube axis direction, respectively. A positioning reference part is formed on the outer wall surface of the body part for positioning at the time of sealing with the cathode ray tube glass panel. In the glass funnel for a cathode ray tube, the reference surface of the positioning reference portion is a press-molded surface, and the 10-point average roughness is Rz, and the average interval of irregularities is Sm, 3 μm ≦ Rz It is characterized by forming a specific rough surface that is ≦ 20 μm and 300 μm ≦ Sm ≦ 800 μm. In addition, the measurement of said Rz and Sm is based on JISB0601: 1982 (hereinafter, the same).

  According to such a configuration, since the reference surface of the positioning reference portion is a press-molded surface, it is possible to avoid an increase in work man-hours and complicated operations by polishing the reference surface after press molding. Further, it is possible to avoid a decrease in the mechanical strength of the funnel accompanying polishing. In addition, by setting the ten-point average roughness Rz and the average period Sm of the unevenness of the reference surface obtained by press molding in the above numerical range, when the jig is brought into contact with the reference surface of the positioning reference portion, the reference surface Scratches can be prevented and wear of the jig tip abutting against the reference surface can also be suppressed.

  That is, if the ten-point average roughness Rz is less than 3 μm, the jig easily comes into contact with the reference surface of the positioning reference portion in the sealing process between the panel and the funnel. Further, if the average interval Sm of the irregularities on the reference surface of the positioning reference portion exceeds 800 μm, the probability that the jig comes into contact with the concave portion among the irregularities on the reference surface increases, and the concave portion is likely to be damaged. For this reason, when such a scratch occurs on the reference surface, there is a risk of causing a failure such as breakage due to the thermal stress at the time of cooling in the sealing process.

  On the other hand, when the ten-point average roughness Rz exceeds 20 μm, wear of the jig tip that comes into contact with the reference surface easily proceeds. In addition, even when the average period Sm of the unevenness is less than 300 μm, the wear of the jig tip is likely to proceed similarly.

  Considering these matters, the surface property of the reference surface of the positioning reference portion is preferably within the above numerical range, the ten-point average roughness Rz is preferably 5 μm ≦ Rz ≦ 15 μm, and the average interval Sm of the irregularities is It is preferable that 400 μm ≦ Sm ≦ 600 μm.

  As described above, according to the glass funnel for a cathode ray tube of the present invention, when the jig is brought into contact with the reference surface of the positioning reference portion, it is possible to prevent the reference surface from being scratched and to contact the reference surface. Abrasion at the tip of the jig to be contacted can also be suppressed. Therefore, the mechanical strength of the funnel is improved, and the positioning accuracy when the jig is brought into contact with the reference surface can be accurately maintained. Furthermore, since the reference surface remains as a press-molded surface, it is possible to provide a high-quality cathode-ray tube funnel that can reduce work man-hours and suppress complicated operations and can perform proper positioning when sealing with a panel. Can do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a glass funnel for a cathode ray tube according to an embodiment of the present invention. In the figure, 1 is a funnel, 2 is a sealing end surface, 3 is a large opening end, 4 is a small opening end, 5 is a side wall portion, 6 is a body portion, 7 is a yoke portion, 8 is a positioning reference portion, and 8a is a positioning reference portion. The reference plane, Z, means the central axis of the funnel 1, and in this embodiment, the surface characteristics of the reference plane 8a of the positioning reference section 8 in the funnel 1 are defined. The explanation is centered.

  As shown in FIG. 1, the funnel 1 according to the embodiment of the present invention includes two adjacent outer wall surfaces of the body portion 6 at two locations on both ends on the long side and one location on one end on the short side. A positioning reference portion 8 is provided. This positioning reference portion 8 has a convex shape having a reference surface 8a at the top (outer periphery of the funnel 1) on which a jig made of a carbon material is abutted, and the reference surface 8a is the central axis of the funnel 1 It is a predetermined distance from Z and is substantially parallel to the central axis of the funnel 1.

  The reference surface 8a of the positioning reference portion 8 has a ten-point average roughness Rz and an average interval Sm of unevenness of 3 μm ≦ Rz ≦ 20 μm (preferably 5 μm ≦ Rz ≦ 15 μm) and 300 μm ≦ The specific rough surface satisfies the relationship of Sm ≦ 800 μm (preferably 400 μm ≦ Sm ≦ 600 μm).

  The reference surface 8a defined as the specific rough surface in the numerical range is previously provided with a specific surface roughness such that the reference surface 8a becomes the specific rough surface in the numerical range on the molding surface of the bottom mold for funnel molding. The mold molding surface is transferred by press molding, and is an unpolished surface as it is.

  If the reference surface 8a of the positioning reference portion 8 is not provided with a specific rough surface in the above numerical range, and the ten-point average roughness Rz is less than 3 μm, the reference surface 8a is used in the sealing process between the panel and the funnel 1. It becomes easy to be damaged when the jig comes into contact with. Further, when the average interval Sm of the unevenness of the reference surface 8a exceeds 800 μm, the probability that the jig comes into contact with the concave portion of the unevenness of the reference surface 8a increases, and the concave portion is easily damaged. For this reason, when such a scratch occurs on the reference surface, there is a risk of causing a failure such as breakage due to the thermal stress at the time of cooling in the sealing process.

  On the other hand, if the ten-point average roughness Rz of the reference surface 8a exceeds 20 μm, the wear of the tip of the jig that comes into contact with the reference surface 8a is likely to proceed. Further, even when the average interval Sm of the unevenness of the reference surface 8a is less than 300 μm, the wear of the jig tip is likely to proceed similarly.

  On the other hand, when the reference surface 8a is a specific rough surface satisfying 3 μm ≦ Rz ≦ 20 μm and 300 μm ≦ Sm ≦ 800 μm, wear of the tip of the jig in contact with the reference surface 8a is possible as much as possible. In addition, it is possible to prevent the cathode ray tube from being damaged during the sealing process due to scratches made on the reference surface 8a.

  Note that the position, number, or shape of the positioning reference portion 8 may be changed as appropriate. Even in this case, the present invention can be applied without any problem by providing a specific rough surface in the above numerical range to the reference surface 8a. can do. In addition, a specific surface roughness such that the reference surface 8a becomes a specific rough surface in the above numerical range is given in advance to at least a molding surface corresponding to the reference surface 8a of the positioning reference portion 8 in the funnel molding bottom mold. Then, if the specific rough surface is transferred to the funnel 1, the effect of the present invention can be sufficiently exerted. However, a specific surface roughness is imparted to the entire molding surface of the bottom mold, and the body portion of the funnel 1 is provided. The entire outer wall surface of 6 may be a specific rough surface in the above numerical range. According to this, the releasability of the funnel 1 from the bottom mold is improved, and the mold life can be improved at the same time.

  As Examples 1 to 3 of the present invention, the funnel 1 in which the ten-point average roughness Rz of the reference surface 8a of the positioning reference portion 8 of the funnel 1 is 3, 8, and 20 μm, and the average interval Sm of the irregularities is constant 500 μm. As a comparative example, a funnel 1 was prepared in which Rz was set to 1, 25 μm, and the average interval Sm between the concaves and convexes was kept constant at 500 μm. The reference surfaces 8a of these funnels 1 are all unpolished surfaces that remain as press-molded surfaces. Then, using a test furnace based on the same temperature control as in the sealing step, it was inspected whether the cathode ray tube (valve) was damaged when the temperature was lowered. The results are shown in Table 1 below. In Table 1 below, “◯” indicates that there is no breakage in 100 cathode ray tubes and is extremely good, and “Δ” indicates that one breakage occurs in 100 cathode ray tubes and is good. That is, “x” means that there are two or more breaks in 100 cathode-ray tubes, which is defective.

  In addition to the above inspection, whether or not the carbon material at the tip of the jig is attached to the reference surface 8a when the jig is brought into contact with the reference surface 8a was visually inspected. The results are shown in Table 1 below. In Table 1 below, “◯” indicates that there is no carbon material adhering to the reference surface 8a of the funnel 1 in 100 cathode ray tubes, and “Δ” indicates 100 cathode ray tubes. Among them, there is only one carbon material adhering to the positioning reference surface 8a of the funnel 1, and “×” means that the carbon material is attached to the reference surface 8a of the funnel 1 in 100 cathode ray tubes. There are two or more that are attached, which means that they are defective.

  According to Table 1 above, in Examples 1 to 3, the ten-point average roughness Rz and the average interval Sm of the unevenness of the reference surface 8a of the positioning reference portion 8 of the funnel 1 are in the numerical range of the specific rough surface. From this, it was confirmed that the cathode ray tube was hardly damaged at the time of temperature drop due to the surface properties of the reference surface 8a. Further, it was confirmed that the carbon material hardly adhered to the reference surface 8a and the jig tip was hardly worn. On the other hand, in Comparative Example 1, the carbon material did not adhere to the reference surface 8a and the jig tip did not wear, but the ten-point average roughness Rz was smaller than the numerical range of the specific rough surface. For this reason, the cathode ray tube was damaged. On the other hand, in Comparative Example 2, although the cathode ray tube was not damaged, since the ten-point average roughness Rz was larger than the numerical range of the specific rough surface, the carbon material adhered to the reference surface 8a, and the jig The tip was worn.

  Next, as Examples 4 to 6 of the present invention, funnels 1 were prepared in which the ten-point average roughness Rz of the reference surface 8a was constant at 8 μm, and the average interval Sm of the irregularities was 300, 500, and 800 μm. Similarly, a funnel 1 having a ten-point average roughness Rz of 8 μm constant and an average interval Sm of the irregularities of 100 and 1000 μm was produced. Then, using a test furnace based on the same temperature control as in the sealing step, the cathode ray tube (valve) is inspected to be damaged when the temperature is lowered, and the jig is brought into contact with the reference surface 8a. Then, a visual inspection was performed to determine whether or not the carbon material at the tip of the jig was attached to the reference surface 8a. The results are shown in Table 2 below. In Table 2 below, “◯”, “Δ”, and “×” mean the same items as above.

  According to Table 2 above, in Examples 4 to 6, since the reference surface of the funnel positioning reference portion is within the numerical range of the specific rough surface, the cathode ray tube at high temperature caused by the surface properties of the reference surface It was confirmed that almost no damage occurred. It was also confirmed that the jig tip did not wear without carbon material adhering to the reference surface. On the other hand, in Comparative Example 3, although the cathode ray tube was not damaged, the carbon material was adhered to the reference surface 8a because the value of the average interval Sm of the unevenness was smaller than the numerical range of the specific rough surface. However, the tip of the jig was worn. On the other hand, in Comparative Example 4, the carbon material adheres to the reference surface 8a, the tip of the jig is worn, and the value of the average interval Sm of the irregularities is larger than the number range of the specific rough surface. Damage has occurred.

It is a perspective view which shows the glass funnel for cathode ray tubes which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass funnel 2 for cathode ray tubes 2 Sealing end surface 3 Large opening end 4 Small opening end 5 Side wall part 6 Body part 7 Yoke part 8 Positioning reference part 8a Reference surface

Claims (1)

The tube has a substantially rectangular large opening end and a substantially circular small opening end at one end and the other end in the tube axis direction, respectively, and extends from the large opening end to the small opening end through a body portion and a yoke portion connected thereto. In a glass funnel for a cathode ray tube, which has a substantially funnel-shaped side wall part, and forms a positioning reference part on the outer wall surface of the body part for positioning when sealing with the cathode ray tube glass panel,
When the reference surface of the positioning reference portion is a press-molded surface, the 10-point average roughness is Rz, and the average interval between the irregularities is Sm, 3 μm ≦ Rz ≦ 20 μm and 300 μm ≦ A glass funnel for a cathode ray tube characterized by having a specific rough surface satisfying Sm ≦ 800 μm.

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