JP2006056732A - Bottom mold for funnel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bottom mold for a glass funnel for a cathode-ray tube coping with trends of wider angle, by enabling enough cooling action to be applied to the outer surface, and reducing possibilities of scattering foreign matter such as dust as much as possible even if the outer surface receives a cooling wind. <P>SOLUTION: In the bottom mold 1 used for forming a funnel, channels 3 for enhancement of cooling formed on the outer surface 2 of the mold 1 are formed so as to extend in the direction parallel to the plane including the central axis of the mold. This bottom mold 1 is preferably for forming a funnel with ≥110° deflection angle. Also the channels 3 for enhancement of cooling may be a plurality of channels formed so as to extend radially from the central axis Z of the mold, or a plurality of channels formed in parallel to each other, and are preferably formed in a local area of the outer surface 2 corresponding to the forming surface part 4 for forming the body part of the funnel. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a funnel bottom mold, and more particularly to a funnel bottom mold in which a groove for promoting cooling is formed on an outer surface.

  As is well known, a cathode ray tube has a glass funnel for a cathode ray tube (hereinafter also simply referred to as a funnel) as one of main glass components. That is, as shown in FIG. 6, the funnel 10 includes a body portion 13 having a seal edge surface 12 at one end in the tube axis X direction as a side wall portion 11 having a substantially funnel shape, and a yoke integrally connected to the body portion 13. Part 14. In this case, the straight line indicated by reference sign SA in the figure represents the short axis, the straight line indicated by sign LA represents the long axis, and the straight line indicated by reference sign DA represents the diagonal axis.

  This funnel 10 is a male mold comprising a bottom mold (bottom mold) and a trunk mold (shell mold), and a hot molten glass lump called a glass gob is supplied to the female mold. The plunger mold) is lowered to cast the molten glass lump. Then, after the molten glass lump is molded into a predetermined shape, the plunger mold is raised and the bottom mold or the like is cooled to apply the cooling function to the original glass of the funnel 10 remaining in these. The molded product is appropriately solidified, and after removing the shell mold, the original glass molded product is taken out from the bottom mold.

  By the way, as shown in FIG. 7, the bottom mold 21 has an inner surface 26 having a molding surface for molding the outer surface of the body portion 13 and the yoke portion 14 of the funnel 10 and the above cooling action. And an outer surface 22 for receiving cooling air. A plurality of cooling-promoting grooves 28 are formed on the outer surface 22 of the bottom mold 21 in the circumferential direction so as to be along a horizontal plane (a plane orthogonal to the mold center axis Z: hereinafter the same). In other words, a plurality of fins 29 formed in the circumferential direction along the horizontal plane are formed, whereby the surface area of the outer surface 22 is increased to obtain a sufficient cooling effect. In FIG. 7, a hatched portion L indicates a longitudinal section cut along the long axis LA, and a hatched portion D represents a longitudinal section cut along the diagonal axis DA. A portion S that represents a plane and is indicated by a one-dot chain line with hatching omitted is a longitudinal section cut along the minor axis SA (the same applies to FIG. 8 below).

  In addition, in the following Patent Documents 1 to 3, it is disclosed that a plurality of cooling promoting grooves formed in the circumferential direction along the horizontal plane are formed on the outer surface of the bottom mold in the same manner as described above. ing.

  On the other hand, in recent years, in order to reduce the depth of the cathode ray tube, a wide-angle glass funnel having a deflection angle of, for example, 110 ° or more has been manufactured. Therefore, it is used for molding this kind of glass funnel. As shown in FIG. 8, the bottom mold 31 has a lower overall height, so that not only the inner surface 36 but also the outer surface 32 rises gently.

Japanese Examined Patent Publication No. 38-21616 Japanese Examined Patent Publication No. 39-13486 Japanese Patent Publication No.49-8686

  By the way, as shown in FIG. 7, when the groove 28 for promoting cooling is formed along the horizontal plane, foreign matter such as dust and powder enters and remains in the groove 28 and the foreign matter is removed. There is a risk that the cooling air will fly up and fly up, and foreign matter may fall into the bottom mold 31. As a result, problems such as deterioration of the quality of the original glass molded product and the funnel may occur.

  In addition, the bottom mold 31 for wide-angle funnel molding shown in FIG. 8 has an inner surface 36 and an outer surface 32 that rise gently, so that the outer surface 32 is cooled in the circumferential direction in a form along a horizontal plane. It is difficult to form the number of promoting grooves so as to obtain a sufficient cooling effect. Therefore, on the outer surface 32 of this type of bottom mold 31, it is difficult to form a groove for promoting cooling or to form an extremely small number of grooves, and it is difficult to perform a sufficient cooling action. .

  The present invention has been made in view of the above circumstances, and even if it is a bottom mold of a funnel whose wide angle is promoted, it is possible to perform a sufficient cooling action on the outer surface thereof, It is a technical problem to reduce as much as possible the probability that foreign matters such as dust will scatter even if the outer surface receives cooling air.

  The present invention made to solve the above technical problem is used in molding a glass funnel for a cathode ray tube, and has a molding die on the inner surface and a groove for promoting cooling formed on the outer surface. The cooling promoting groove is formed to extend in a direction parallel to a plane including the mold center axis.

  According to such a configuration, the groove for promoting cooling is formed on the outer surface of the bottom mold so as to extend in a direction parallel to the plane including the mold center axis (funnel tube axis). Even if it is a bottom mold for funnel molding with a wide angle, that is, a bottom mold with a low overall height and a gentle rise on the inner and outer surfaces, a sufficient number of grooves for promoting cooling on the outer surface Can be formed. As a result, the surface area of the outer surface of the bottom mold becomes sufficiently large, and it is possible to perform a good cooling action on the funnel (original glass molded product) inside the bottom mold when receiving cooling air. Become. In this case, if the bottom surface or the side surface of the groove for promoting cooling is roughened or roughened, the surface area of the outer surface of the bottom mold can be efficiently widened to further improve the cooling effect. It becomes possible to plan. In addition, the groove for promoting cooling having such directionality is, in other words, formed in a form along or close to a vertical plane (a plane parallel to a plane including the tube axis: hereinafter the same), Since the groove is open at the bottom, it is possible to suppress or eliminate foreign matter such as dust from remaining inside the groove. As a result, it is possible to avoid as much as possible the problem that foreign matter rises by the cooling air and falls into the bottom mold and causes deterioration of the funnel quality.

  In the above configuration, the funnel bottom mold is preferably used for molding a glass funnel for a cathode ray tube having a deflection angle of 110 ° or more.

  In this way, a bottom mold used for molding a funnel having a deflection angle of 110 ° or more, that is, a groove for promoting cooling along the horizontal plane in the circumferential direction is formed because the total height is extremely low. It is possible to form a sufficient number of grooves for promoting cooling that have the same effect on cooling even in the case of a bottom mold that is difficult to cool, and a good cooling action is performed when molding this type of funnel. Will get.

  In this case, as a specific example, the cooling promotion groove may be composed of a plurality of grooves formed in a direction extending radially from the mold central axis, and a plurality of grooves parallel to each other. You may make it consist of a groove | channel.

  In this way, in any case, the various advantages already described can be enjoyed.

  In the above configuration, the cooling promotion groove is preferably formed in a partial region of the outer surface corresponding to a portion of the molding surface for molding the body portion of the glass funnel for a cathode ray tube.

  In this way, the body part, which is a part having a large heat capacity because it is thicker than the yoke part, is cooled particularly efficiently, and cooling is promoted on the outer surface part corresponding to the molding surface part for molding the yoke part. Therefore, the groove forming operation can be simplified.

  In the above configuration, it is preferable that the cooling promoting groove is formed by cutting.

  That is, if the groove for promoting cooling is formed by cutting (preferably, cutting with a milling cutter), for example, the shape can be changed or adjusted more delicately than in the case of casting, so that the cooling efficiency can be made uniform. It is possible to make the temperature of the original glass molded product existing in the bottom mold uniform. In addition, it is possible to form a groove for promoting cooling by casting (for example, precision casting). In this way, the work can be facilitated as compared with the case of forming a groove along the horizontal plane in the circumferential direction. Equipment can be simplified.

  In the above configuration, the cooling promoting groove is formed in the circumferential direction formed on the outer surface above the groove in addition to the groove formed to extend in a direction parallel to the plane including the mold central axis. It can have an extending groove.

  In this way, if only the cooling promoting groove formed so as to extend in a direction parallel to the plane including the mold center axis cannot sufficiently obtain the cooling effect on the upper portion, the outer portion of the portion is removed. Insufficient cooling can be compensated by a circumferentially formed groove formed on the surface, and a sufficient cooling effect can be obtained over a wide area, particularly in the case of a large bottom mold.

  As described above, according to the funnel bottom mold according to the present invention, the cooling promoting groove is formed on the outer surface of the bottom mold so as to extend in a direction parallel to the plane including the mold center axis. Therefore, it is possible to form a sufficient number of grooves for promoting cooling even when the bottom mold has a low overall height and a gentle rise on the inner surface and outer surface. It is possible to ensure a sufficiently large surface area and to perform a good cooling action on the funnel (original glass molded product) having a wide angle. Moreover, since the groove for promoting cooling having such directivity is formed in a form along or close to the vertical plane, it is possible to prevent foreign matters such as dust from remaining inside the groove. As a result, it is possible to avoid as much as possible the problem that the foreign matter rises by the cooling air and falls into the bottom mold and causes the quality of the funnel to deteriorate.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a plan view showing a main part of a funnel bottom mold according to the first embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of the funnel bottom mold. In FIG. 2, a hatched portion L represents a longitudinal section cut along the long axis LA, and a hatched portion D represents a longitudinal section cut along the diagonal axis DA. A portion S that represents a plane and is indicated by a one-dot chain line with hatching omitted is a longitudinal section cut along the minor axis SA (the same applies to FIG. 3 below).

  The funnel bottom mold according to the first embodiment is used for forming a funnel having a deflection angle of 120 ° and a deflection angle of 120 °. As shown in FIGS. 1 and 2, the outer surface 2 of the bottom mold 1 extends in a direction parallel to the plane including the mold center axis Z. A plurality of grooves 12 (12 to 60, 36 in the illustrated example) for promoting cooling are formed so as to extend radially from the axis Z. Along with this, these cooling promotion grooves 3 are formed along the vertical plane, and are formed in a form in which the lower part is opened.

  These cooling promoting grooves 3 are formed in a partial region of the outer surface 2 existing on the back side of the molding surface portion 4 for molding the body portion of the funnel, and accordingly, the molding surface portion 5 for molding the yoke portion of the funnel. There is no cooling promoting groove 3 on the back side. Further, the grooves 3 for promoting cooling are formed at equal angles (10 °), and the width of each groove 3 is 10 mm. In addition, the thickness between the bottom face 3a of each groove | channel 3 and the inner surface 6 (molding surface part 4) in the bottom metal mold | die 1 is made equal thickness (about 25 mm) over the full length.

  Further, these cooling promoting grooves 3 are formed by cutting with a milling cutter. In this case, preferably, the bottom surface 3a and / or the side surface 3b of the groove 3 for promoting cooling is formed to have irregularities or a rough surface for the purpose of increasing the surface area. The outer surface 2 of the bottom mold 1 is supplied with cooling air from a cooling air supply means (not shown) in the latter half of the press molding process. In addition, an ejector rod 7 that moves upward when taking out the funnel (original glass molded product) that has been cooled is disposed in the center of the bottom of the bottom mold 1.

  According to the bottom mold 1 in which the groove 3 for promoting cooling as described above is formed, since the overall height is low and the rise of the inner surface 6 and the outer surface 2 is gentle, the groove along the horizontal plane is formed in the circumferential direction. In spite of this difficulty, a sufficient number of cooling promoting grooves 3 are formed, and the surface area of the outer surface 2 of the bottom mold 1 is effectively increased. In the latter half of the period, it becomes possible to perform a good cooling action on the funnel (original glass molded product) having a wide deflection angle remaining in the bottom mold 1.

  Further, since the cooling promoting groove 3 is formed in a form along the vertical plane and opened downward, foreign matter such as dust does not remain inside the groove 3, and the foreign matter rises by the cooling air. The problem of falling into the inside of the bottom mold 1 and degrading the quality of the funnel is avoided as much as possible. In addition, since the plurality of cooling promoting grooves 3 are formed radially from the mold center axis Z, the flow of the cooling air along each groove 3 becomes uniform and smooth.

  In the first embodiment, the cooling promoting grooves 3 are formed around the major axis LA, around the minor axis SA, and around the diagonal axis DA, that is, at equal angles over the entire circumference. The grooves 3 may not be formed in the vicinity of the short axis SA that does not require much cooling as compared with the vicinity of the long axis LA and the periphery of the diagonal axis DA.

  FIG. 3 illustrates a bottom mold 1 for funnels according to the second embodiment of the present invention. The bottom mold 1 is used to mold a funnel having a 32 inch deflection angle of 120 °. The bottom mold 1 according to the second embodiment is different from the bottom mold 1 according to the first embodiment described above so as to extend in a direction parallel to the plane including the mold center axis Z. In addition to the above-described grooves 3 similar to those described above, cooling promotion is provided along a horizontal plane extending in the circumferential direction of one step (may be a plurality of steps) above the grooves 3 on the outer surface 2 of the bottom mold 1. This is the point where the groove 8 is formed.

  According to the bottom mold 1 according to the second embodiment, only the cooling promotion groove 3 formed so as to extend in a direction parallel to the plane including the mold center axis Z has a sufficient cooling effect on the upper portion thereof. In this case, insufficient cooling can be compensated by the circumferentially extending groove 8 formed in the upper part of the groove. Since other configurations and operational effects are substantially the same as those of the bottom mold 1 according to the first embodiment described above, in FIG. Is omitted.

  4 and 5 are schematic bottom views schematically showing funnel bottom molds 1 and 1 according to the third embodiment and the fourth embodiment of the present invention, respectively. That is, the bottom mold 1 according to the third embodiment shown in FIG. 4 is formed by forming, on the outer surface 2, a plurality of cooling promoting grooves 3 extending in parallel with the long axis LA at equal intervals. The bottom mold 1 according to the fourth embodiment shown in FIG. 5 has a plurality of cooling promoting grooves 3 extending in parallel to the short axis SA on the outer surface 2 at equal intervals. The bottom molds 1 and 1 according to the third and fourth embodiments can enjoy substantially the same operational effects as the bottom mold 1 according to the first embodiment described above. Further, for the bottom molds 1 and 1 according to the third and fourth embodiments, similarly to the bottom mold 1 according to the second embodiment described above, cooling promotion along a horizontal plane extending in the circumferential direction in the upper portion is performed. A groove may be formed.

It is a top view which shows the principal part of the bottom metal mold | die for funnels concerning 1st Embodiment of this invention. It is a longitudinal cross-sectional view which shows the bottom metal mold | die for funnels concerning 1st Embodiment of this invention. It is a longitudinal cross-sectional view which shows the bottom metal mold | die for funnels concerning 2nd Embodiment of this invention. It is a schematic bottom view which shows typically the bottom metal mold | die for funnels concerning 3rd Embodiment of this invention. It is a schematic bottom view which shows typically the bottom metal mold | die for funnels concerning 4th Embodiment of this invention. It is a perspective view which shows the outline of the glass funnel for cathode ray tubes. It is a longitudinal cross-sectional view which shows the conventional bottom mold for funnels. It is a longitudinal cross-sectional view for demonstrating the problem regarding the conventional bottom mold for funnels.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Funnel bottom metal mold | die 2 Outer surface 3 Cooling promotion groove | channel 4 Body part molding surface part 5 Yoke part molding surface part 6 Inner surface 8 Circumferential cooling promotion groove Z Mold central axis

Claims (7)

In the bottom mold, which is used for molding a glass funnel for a cathode ray tube and has a molding surface on the inner surface and a groove for promoting cooling is formed on the outer surface,
The funnel bottom mold, wherein the cooling promoting groove is formed to extend in a direction parallel to a plane including a mold central axis.   The bottom mold for funnels according to claim 1, which is used for molding a glass funnel for a cathode ray tube having a deflection angle of 110 ° or more.   The funnel bottom mold according to claim 1, wherein the cooling promotion groove includes a plurality of grooves formed in a direction extending radially from a mold central axis.   The funnel bottom mold according to claim 1, wherein the cooling promotion groove is composed of a plurality of grooves parallel to each other.   The said groove | channel for cooling promotion is formed in the partial area | region of the outer surface corresponding to the site | part of the molding surface which shape | molds the body part of the glass funnel for cathode ray tubes. Bottom mold for funnel.   The funnel bottom mold according to any one of claims 1 to 5, wherein the cooling promotion groove is formed by cutting.   The groove for promoting cooling has a groove extending in the circumferential direction formed on the outer surface above the groove in addition to the groove formed to extend in a direction parallel to the plane including the mold center axis. The bottom mold for funnels according to any one of claims 1 to 6, wherein the bottom mold is for funnels.

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