JP2006156210A - Glass funnel for cathode-ray tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve productivity while restraining occurrence of a crease and a crack in press molding by making a shape of a positioning reference part formed in a body part of a funnel and a property of its outside surface appropriate, and to reduce weight while eliminating difficulty of work at the same time. <P>SOLUTION: Outside surfaces of ends on both side in the width direction of at least a reference surface 7a of the positioning reference part 7 and a connection part 7c thereof from an end on the side of a small opening end 3 to an outside surface 4c of the body part 4 are left in a press-molded state; a connection line C continuing by gradually approaching the outside surface 4c of the body part 4 from the end on the small opening end 3 side of the reference surface 7a comprises a projecting curved line C1, an intermediate line L1 and a recessed curved line C2; a straight line LA connecting a connection point J2 between the projecting curved line C1 and the intermediate line L1 and a connection point J3 between the recessed curved line C2 and the intermediate line L1 is inclined at an angle θ1 of 2° to 25° with respect to a surface vertical to a tube axis Z. <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 making the shape of a positioning reference portion formed in a body portion, the properties of its outer surface, and the like appropriate.

  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 includes a face portion having an effective screen for displaying an image, and a skirt portion having a substantially rectangular opening end connected to the face portion via a blend R portion and used for sealing with the funnel. The skirt portion includes two long side portions facing each other and two short side portions facing each other.

  On the other hand, the funnel has a substantially rectangular large opening end provided for sealing with the panel at one end and the other end in the tube axis direction, and a substantially circular small opening end provided for welding with the neck, respectively. The funnel side wall portion having the tube axis as the central axis is substantially funnel-shaped, and includes a body portion that extends from the large opening end toward the small opening end side, and a yoke portion that continues to the small opening end side of the body portion. The body portion includes two long side portions facing each other and two short side portions facing each other at a large opening end side portion. The sealing end surface at the large opening end of the funnel is welded and joined to the sealing end surface at the opening end of the panel with frit glass interposed. In this case, the thickness of the large opening end of the funnel is set to be thicker than the thickness of the small opening end. Therefore, the thickness of the side wall portion of the funnel shifts from the large opening end side to the small opening end side. It is gradually decreasing with.

  When the sealing position of the panel and the funnel configured as described above is slightly misaligned with respect to the tube axis, a normal image is displayed on the image display surface of the cathode ray tube (panel image display surface). Therefore, a positioning reference portion having a reference point for determining the relative position of the two is formed in the vicinity of the large opening end of the panel and the funnel. These positioning reference portions have a reference surface having a predetermined area including the reference point. When sealing the panel and the funnel, the positioning jigs are relatively pressed by pressing the positioning jigs against the reference surfaces of both positioning reference portions. The actual situation is that the positioning is performed properly.

  Here, when focusing on the positioning reference portion of the funnel, for example, according to Patent Document 1 below, the outer surface of the body portion is positioned so that the reference surface is located outward from the maximum outline of the body portion (mold match line). A positioning reference portion formed so as to project is disclosed. The positioning reference portion is formed in the vicinity of both end portions of one long side portion on the large opening end side of the body portion and in the vicinity of one end portion of one short side portion. Two positioning reference parts exist in the vicinity of one diagonal part among the parts.

  Further, for example, according to Patent Document 2 below, the reference portion of the positioning reference portion is formed as a flat surface continuously extending from the mold match line of the body portion toward the small opening end side, thereby forming the positioning reference portion forming portion. Is disclosed to reduce the glass thickness from the reference surface to the inner surface of the body part.

  Note that each funnel having the above-described structures is a female mold composed of a bottom mold (bottom mold) 10 and a trunk mold (shell mold) 11 as shown in FIG. 12 is supplied with a high-temperature molten glass lump G called a glass gob, and then, as shown in FIG. 4B, the male die (plunger mold) 13 is lowered to push the molten glass lump G. It is press-molded by rolling and rolling up the stretched molten glass lump G along the molding surfaces of the molds 10, 11, and 13. After the molten glass block G is molded into a predetermined shape, as shown in FIG. 4 (c), the plunger mold 13 is raised, and the shell mold 11 is further removed. On the other hand, by applying a cooling action, the funnels F remaining inside are appropriately solidified, and thereafter, the funnels F are taken out from the bottom mold 10. In this case, a molding surface portion corresponding to the shape of the positioning reference portion is formed on the bottom mold 10, and therefore a portion corresponding to the positioning reference portion is integrally formed on the body portion by this press molding. Is obtained.

JP 54-131864 A JP 2003-109520 A

  By the way, the positioning reference part (pad) disclosed in Patent Document 1 is the same as the glass thickness at the large opening end (sealing end surface) as shown by a chain line (reference numeral 25) in FIG. A base pad that protrudes outward by a certain amount and that is about twice as long as the required length on the small opening end side is prepared in advance by press molding, and then obtained by cutting the base pad. Is. At the time of press molding to form this base pad, the molten glass is stretched and crawls up as described above, but the molten glass reaches and fills first in the vicinity of the large opening end. The portion to be applied is around the central portion in the width direction of the long side portion of the body portion, whereas the periphery of the diagonal portion is finally filled with molten glass. In this case, despite the fact that two base pads are formed in the vicinity of one diagonal portion, when the molten glass arrives in the vicinity of this diagonal portion, the molten glass is in contact with the mold for a long time. Since the glass temperature is lowered due to, for example, the viscosity is increased, the fluidity of the glass deteriorates in the vicinity of the diagonal part of the large opening end and the formation position of the base pad, and wrinkles and cracks are generated in those parts. There was a problem that occurred.

  Such a problem is not limited to the funnel disclosed in Patent Document 1, but is a problem that has generally occurred in the past. And as an example of the measure for coping with this, in the funnel disclosed in Patent Document 1, the entire area of the base pad is cut. However, with such a method, the labor and labor required for cutting become enormous, leading to an increase in work man-hours and deterioration in workability, and in particular, the reference surface of the positioning reference portion (pad) and the outer surface of the body portion. Since it is preferable to make the connecting portion into a curved and complicated shape in order to reduce the weight or the like, the difficulty of the cutting operation becomes more remarkable.

  On the other hand, since the positioning reference portion disclosed in Patent Document 2 is thinned as described above, in addition to being able to moderately suppress the occurrence of the wrinkles and cracks during press molding, And the advantage that cutting work becomes unnecessary can be enjoyed. However, the positioning reference portion disclosed in Patent Document 2 has a cross-sectional contour of the connecting portion between the reference surface and the outer surface of the body portion as described in the same document (FIG. 2 of the same document). As shown by reference numeral 6z, it extends along a straight line having an inclination. When the thinning of the positioning reference portion is sufficient as described above, if the cross-sectional contour of the connecting portion extends along a straight line having an inclination, the presence of the reference surface of the positioning reference portion can be visually confirmed. It becomes difficult to catch. For this reason, it is necessary to separately provide convex or concave markings in the vicinity of the reference surface, which causes a problem that the shape around the positioning reference portion is complicated and the design and manufacture of the mold is also complicated.

  Moreover, the general shape of the connecting portion in the prior art is as described in the same document (FIGS. 6 and 8 of the same document). That is, as shown in FIG. 5A, the reference surface 17a of the positioning reference portion 17 is formed at a position protruding outward from the mold match line 16, and then the molten glass is improved in fluidity and positioned. For the purpose of smoothly filling the reference portion 17 with molten glass, a connecting portion 17c from the end portion 17x on the small opening end side of the reference surface 17a toward the outer surface 14c of the body portion 14 is a surface orthogonal to the tube axis ( The surface is inclined along a straight line having an inclination angle θ of 30 ° or more with respect to the surface indicated by the alternate long and short dash line in FIG. However, when the connecting portion 17c has a shape along a straight line and the inclination angle θ is 30 ° or more, the thick glass portion due to the presence of the positioning reference portion 17 is widespread. In this case, too much emphasis is placed on smoothly filling the positioning reference portion 17 with molten glass, and there is a portion where the glass thickness is unnecessarily increased. Then, if there is such an unnecessary thick portion in the positioning reference portion 17, good moldability is hindered, and as shown in FIG. 5 (b), the positioning reference portion 17 in the body portion 14. Deformation X occurs on the inner surface 14d.

  The base pad indicated by the chain line (reference numeral 25) in FIG. 3 of Patent Document 1 is similarly formed with a connecting portion along a straight line, but the inclination angle with respect to a plane perpendicular to the straight tube axis is 30. It is illustrated as below. However, since this base pad is removed by cutting even if wrinkles or the like are generated, it can be found that the inclination angle of the linear portion is illustrated as 30 ° or less. Can not. That is, the linear portion of the connecting portion in the base pad does not have to have the above inclination angle of 30 ° or less, but rather the above inclination angle in order to smoothly fill the molten glass with the base pad. It is preferable that the angle is preferably 30 ° or more.

  Considering the above matters, conventionally, in order to achieve smooth filling of the molten glass into the positioning reference portion so as to suppress the occurrence of wrinkles and cracks, the connecting portion is formed along a straight line. The conclusion that the above-mentioned inclination angle should be 30 ° or more is obtained, but in this case, the positioning reference portion becomes thick over a wide range as described above, and the corresponding position of the body portion is determined. In order to achieve sufficient thinning of the positioning reference part against the deformation of the inner surface, it becomes necessary to separately form markings, etc., and further thinning and light weight in a form that does not require markings, etc. To achieve this, complicated grinding work is required.

  In particular, in recent years, there has been a growing demand for improved productivity and weight reduction, but if the press molding time is shortened in order to improve the former productivity, the area around the positioning reference part It becomes difficult to fill the molten glass, and generation of wrinkles and cracks becomes remarkable. In order to reduce the weight of the latter, the work becomes more difficult due to the necessity of marking and grinding work. Therefore, there is a problem of what measures are best taken to improve productivity while suppressing the occurrence of wrinkles and cracks, and at the same time to reduce weight while eliminating difficult work. .

  The present invention has been made in view of the above circumstances, and the occurrence of wrinkles and cracks during press molding is achieved by appropriately adjusting the shape of the positioning reference portion formed on the body portion of the funnel and the properties of the outer surface thereof. It is a technical problem to improve productivity while suppressing the above and to reduce the weight while making difficult work unnecessary.

  The present invention devised to solve the above technical problem is a substantially funnel-shaped side wall portion in which a substantially rectangular large opening end and a substantially circular small opening end are respectively formed at one end and the other end in the tube axis direction. A positioning reference part having a reference surface is formed on the body part from the large opening end toward the small opening end side of the side wall part, and the connecting part extending from the reference surface to the outer surface of the body part, As an outline of a cross section that passes through the center in the width direction of the reference surface and is parallel to the tube axis and perpendicular to the reference surface, gradually approaches the outer surface of the body portion from the end on the small opening end side of the reference surface In a glass funnel for a cathode ray tube having continuous connecting lines, at least the outer surface of the connecting portion extending from the end on both sides in the width direction of the reference surface and the end on the small opening end side to the outer surface of the body portion is press-molded. The surface as it is and the connecting line From the end on the small opening end side of the reference surface, through the convex curve line having the center of curvature inward, the intermediate line, and the concave curve line having the center of curvature outward, the outside of the body part As the straight line connecting the connecting points between the convex curved line and the intermediate line and the connecting point between the concave curved line and the intermediate line moves smoothly outwards, It is characterized in that it is inclined at an angle of 2 ° or more and 25 ° or less with respect to a plane perpendicular to the tube axis with a directivity close to the large opening end side.

  Here, the above-mentioned “at least the outer surface of the connecting portion extending from the end portion on both sides in the width direction of the reference surface and the end portion on the small opening end side to the outer surface of the body portion is a press-molded surface” The reference surface itself may be a surface that has been press-molded, and the connection portion that extends from the end of the large opening end side of the reference surface to the outer surface of the body portion, but the connection portion and the reference surface are flat. Since it is a surface or a surface according to this, it is possible to easily perform polishing or the like. Therefore, it means that these surfaces may be press-molded surfaces or may be polished surfaces. The “intermediate line” is a curve or straight line having a radius of curvature much larger than that of the “convex curved line” and the “concave curved line”, and the above “convex curved line” and “concave bay”. A “curve” is a curve that can be clearly understood to be curved at first glance. In order to clarify the description of the above-mentioned "convex curved line having a center of curvature on the inside, intermediate line, and concave curved line having a center of curvature on the outside" The three lines are arranged in the above described order from the end portion on the small opening end side of the reference surface toward the outer surface of the body portion.

  According to the above configuration, the outer surface of the connecting portion from the end on both sides in the width direction of the reference surface and the end on the small opening end side to the outer surface of the body portion is a surface that has been press-molded. Even if the connecting portion has a complicated shape having a curved surface for the purpose of reducing the weight within a range that does not cause deterioration of the moldability, grinding or polishing is unnecessary, so that the work is complicated. There is no increase in work man-hours, and it can greatly contribute to the improvement of productivity. Moreover, the connecting line in the predetermined cross section of the connecting portion is composed of a convex curve line, an intermediate line, and a concave curve line, and a straight line connecting two connection points at both ends of the intermediate line in these three lines. Is inclined in the predetermined direction at an angle of 2 ° or more and 25 ° or less with respect to a plane perpendicular to the tube axis, the connecting line has an S-shape or a shape similar thereto, The middle part of the connecting line is constricted inward. Therefore, a state in which the middle of the straight line portion of the connecting line in the conventional connecting portion, that is, the middle of the straight line portion inclined at an angle of 30 ° or more in the predetermined direction over a long range is cut away by constriction inward. It becomes. As a result, while maintaining the shape in which the flowability and scooping of the molten glass are not hindered by the presence of the positioning reference portion during press molding, the problem that the positioning reference portion becomes thick over a wide range is avoided, and the positioning reference portion In the vicinity of the large opening end (sealing end surface) in the vicinity of the center, especially around the large opening end of the diagonal portion where the two positioning reference parts are arranged in close proximity, wrinkles and cracks are less likely to occur, and positioning in the body part Deformation of the inner surface of the reference portion is less likely to occur. Further, if the connecting portion has such a shape, the presence of the reference surface can be clearly seen, so that it is not necessary to separately form a marking or the like, and there is no possibility of complicating the design and production of the mold. In this case, if the inclination angle is less than 2 °, the thickness of the connecting portion from the reference surface of the positioning reference portion to the outer surface of the body portion will change abruptly in the middle. Does not smoothly fill the positioning reference part, causing wrinkles and cracks in the positioning reference part itself, and if it exceeds 25 °, the positioning reference part becomes thick over a wide area, and the wrinkles around the large opening end described above. The probability of occurrence of cracks increases. Therefore, if this inclination angle is within the above numerical range, it is possible to preferably avoid these problems.

  In this case, the width (thickness) of the sealing end surface formed at the large opening end of the body portion is a, and the reference surface of the positioning reference portion protrudes outward from the mold match line of the body portion (maximum protrusion) When (dimension) is b, the value of b / a is preferably 0.714 or less. The maximum protrusion dimension b is preferably 5 mm or less, and more preferably 3 mm or less.

  In this way, the projection dimension of the reference surface of the positioning reference part itself from the outer surface of the body part is shortened, and in combination with the shape of the connecting part as described above, the positioning reference part at the time of press molding The molten glass is filled more smoothly, and the probability of occurrence of wrinkles and cracks is drastically reduced. Then, considering such matters and the fact that the positioning reference portion should protrude moderately so that its presence can be clearly recognized, the value of b / a is 0.062 or more and More preferably, it is 0.333 or less. However, the reference surface of the positioning reference portion may be a flat surface continuously from the mold match line of the body portion toward the small opening end side, or a position separated from the mold match line of the body portion toward the small opening end side. It may be a flat surface starting from the side toward the end of the small opening.

  The total length of the convex curved line and the concave curved line is preferably 50% or more of the total length of the connecting line, and more preferably 60% or more.

  In this way, the length of the convex curved line and the concave curved line occupied in the connecting line is sufficient, and even if the intermediate line is a straight line, the connecting line as a whole is smoothly curved S. The curve can be made closer to the character, and the weight can be efficiently reduced. At the same time, the smoothness of the flow of the molten glass at the time of press molding can be appropriately maintained.

  In the above configuration, the convex curve line is preferably an arc having a radius of 1 mm or more and 3 mm or less.

  In this way, if the convex curved line is formed by an arc, design and production and maintenance around the positioning reference portion in the mold becomes easier than when the curved line is formed by other curved lines such as a hyperbola or a parabola. In this case, if the radius of the arc exceeds 3 mm, the length of the positioning reference portion in the tube axis direction may become unduly long, so the glass amount (volume) of the positioning reference portion increases, and the body portion described above This causes a problem that deformation occurs on the inner surface of the corresponding part. If the radius of the arc is less than 1 mm, the flow of the molten glass is obstructed and sufficient filling is not performed, or even if sufficient filling is performed, the periphery of the convex curved portion is compared with other parts. Therefore, it becomes a factor that increases defects such as cracks and chips. Therefore, if the radius of the arc of the convex curved portion is within the above numerical range, it is possible to make these problems difficult to occur. In addition, it is preferable that the convex curve line is smoothly connected to the reference surface of the positioning reference portion, and in particular, the tangent of the end portion of the convex curve line is coincident with the straight line forming the cross-sectional contour of the reference surface. . Further, it is preferable that the convex curve line and the intermediate line are coincident with each other at the connection point, in other words, both are circumscribed or inscribed.

  In the above configuration, the concave curved line is preferably an arc having a radius that circumscribes the outer surface of the body portion of 10 mm or more and 20 mm or less.

  If the concave curved line is formed in an arc shape in this way, the concave curved portion is a portion in contact with the outer surface of the body portion. Therefore, the flow of the molten glass can be made smooth during press molding, and molding inhibition is unlikely to occur. It becomes possible to do. In this case, when the aforementioned inclination angle is not less than 2 ° and not more than 25 ° and the radius of the arc exceeds 20 mm, the tube axis direction from the outer surface of the body part to the reference surface in the connecting line is increased. Since there is a possibility that the length becomes longer, the glass amount (volume) of the positioning reference portion is unduly increased, which causes a deformation of the inner surface of the corresponding portion in the body portion described above. Also, if the radius of this arc is less than 10 mm, the wall thickness changes abruptly immediately after moving from the body portion to the location where the positioning reference portion is formed. As a result, the molten glass is not sufficiently filled in the vicinity, and the probability of occurrence of soot is increased. Therefore, if the radius of the arc is within the above numerical range, it is convenient to avoid these problems. Note that it is preferable that the tangent line of the concave curve and the intermediate line are coincident with each other at the connecting point, in other words, both are circumscribed or inscribed.

  In the above configuration, the intermediate line is preferably substantially a straight line.

  That is, this intermediate line can be a convex or concave curved line having a larger radius of curvature than the above two curved lines, but by making it substantially straight, the total length of the connecting line is minimized. The flow of the molten glass can be made smooth, and the mold can be designed and manufactured easily.

  Further, the present invention created to solve the above technical problem is a substantially funnel-like shape in which a substantially rectangular large opening end and a substantially circular small opening end are respectively formed at one end and the other end in the tube axis direction. A positioning reference portion having a reference surface is formed on a body portion that includes a side wall portion and that extends from the large opening end toward the small opening end side of the side wall portion, and a connecting portion that extends from the reference surface to the outer surface of the body portion. As a contour of a cross section that passes through the center in the width direction of the reference plane and is parallel to the tube axis and perpendicular to the reference plane, gradually from the end on the small opening end side of the reference plane to the outer surface of the body part In the glass funnel for a cathode ray tube having a connecting line that is close to each other, at least the outer surface of the connecting portion extending from the end on both sides in the width direction of the reference surface and the end on the small opening end side to the outer surface of the body portion, A surface that has been press-molded, and The connection from the end of the small opening end side of the reference surface to the outer surface of the body portion via a convex curve line having a center of curvature inward and a concave curve line having a center of curvature outward. In addition to being connected smoothly, the tangent line of the convex curve line or the concave curve line at the connection point between the convex curve line and the concave curve line becomes closer to the large opening end side as it moves outward. It has a directivity and is inclined at an angle of 2 ° or more and 25 ° or less with respect to a plane perpendicular to the tube axis.

  According to such a structure, the connection line in the said predetermined cross section of a connection part is comprised only from a convex curve line and a concave curve line, The convex curve line or concave bay in the connection point of these two lines The tangent line of the curve is inclined in the predetermined direction at an angle of 2 ° or more and 25 ° or less with respect to a plane perpendicular to the tube axis. That is, this connecting line is composed of only two types of curved lines, and is different from the above-described connecting line only in that it does not have an intermediate line. With such a configuration, from the connection point of the convex curved line to the end on the small opening end side of the reference surface of the positioning reference portion, such as a funnel with a small deflection angle of the cathode ray tube, the outside of the body portion It is effective when applied to a funnel having a short distance in the direction perpendicular to the tube axis up to the connection point of the concave curved line to the side surface. And the point that the outer surface of the connecting portion extending from the end portion on both sides in the width direction of the reference surface and the end portion on the small opening end side to the outer side surface of the body portion is a press-molded surface, and the above With respect to the point that the inclination angle is 2 ° or more and 25 ° or less, the same operational effects as those already described in the corresponding configuration can be obtained. The two curved lines are preferably circumscribed.

  In this configuration, the convex curved line is preferably an arc having a radius of 1 mm or more and 3 mm or less, and the concave curved line is an arc having a radius of 10 mm or more and 20 mm or less circumscribing the outer surface of the body part. It is preferable that

  Thus, the convex curved line is an arc and the radius is 1 mm or more and 3 mm or less, and the concave curved line is an arc circumscribing the outer surface of the body part and the radius is 10 mm or more and 20 mm. With respect to the following points, the same operational effects as those described in the corresponding configuration can be obtained.

  Also in this case, for the same reason as described above, the value of b / a is preferably 0.714 or less, more preferably 0.062 or more and 0.333 or less, and the maximum protrusion dimension b described above. Is preferably 5 mm or less, more preferably 3 mm or less.

  As described above, according to the glass funnel for a cathode ray tube according to the present invention, the outer surface of at least a predetermined portion of the joint portion between the reference surface of the positioning reference portion and the outer surface of the body portion is a surface that is press-molded. Therefore, even if this connecting part has a complicated shape with a curved surface, grinding or polishing is not required, so there is no complication of work or an increase in work man-hours and a significant improvement in productivity. Is planned. Moreover, the connecting line in the predetermined cross section of the connecting portion is composed of a convex curve line, an intermediate line, and a concave curve line, and a straight line connecting two connection points at both ends of the intermediate line in these three lines. However, since it is inclined in the predetermined direction at an angle of 2 ° or more and 25 ° or less with respect to a plane perpendicular to the tube axis, the connecting line has an S-shape or a shape similar thereto. As a result, the problem that the positioning reference portion becomes thick over a wide range is avoided, and it is difficult for wrinkles and cracks to occur around the large opening end (sealing end surface) in the vicinity of the positioning reference portion, and the body portion. Also, deformation of the inner surface of the positioning reference portion is difficult to occur. Further, if the connecting portion has such a shape, the presence of the reference surface can be clearly recognized, so that it is not necessary to separately form a marking or the like, and there is no possibility of complicating the design and production of the mold.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an overall configuration of a glass funnel for a cathode ray tube according to the first embodiment of the present invention, FIG. 2 is an enlarged longitudinal sectional view of a main part cut along line AA in FIG. 1, and FIG. FIG. 5 is an enlarged longitudinal sectional view of a main part of a glass funnel for a cathode ray tube according to a second embodiment of the present invention.

  As shown in FIG. 1, the funnel 1 according to the first embodiment of the present invention has a substantially rectangular large opening end 2 provided for sealing with a panel (not shown) at one end in the tube axis Z direction. At the other end in the same direction, there is a substantially circular small opening end 3 to which a neck tube (not shown) is welded. The side wall portion of the substantially funnel-shaped funnel 1 having the tube axis Z as the central axis is composed of a body portion 4 extending from the large opening end 2 to a predetermined position on the small opening end 3 side, and a yoke connected to the small opening end 3 side. The body portion 4 includes two long side portions 4a facing each other on the large opening end 2 side and two short side portions 4b facing each other.

  In the body portion 4, a mold match line 6 that is the maximum outer shape line is formed at a position spaced a small distance from the large opening end 2 toward the small opening end 3, and the small opening is formed from the mold match line 6. A total of three positioning reference portions 7 are formed in a region reaching a predetermined position on the end 3 side. Specifically, the positioning reference portion 7 is formed in the vicinity of both ends in the width direction of one long side portion 4a on the large opening end 2 side of the body portion 4 and in the vicinity of one end portion in the width direction of one short side portion 4b. The entire outer surface is an unpolished surface that has been press-molded. And in these positioning reference | standard parts 7, the reference surface 7a of the predetermined area containing the reference point at the time of a positioning jig contact | abutting at the time of sealing with a panel is formed. The reference surface 7a may be a polished surface.

  FIG. 2 shows the shape of a cross section (cross section taken along line AA in FIG. 1) passing through the center portion in the width direction of the reference surface 7a of the positioning reference portion 7 and parallel to the tube axis Z and perpendicular to the reference surface 7a. For the sake of convenience, hatching is omitted. As shown in the figure, the positioning reference portion 7 has a reference surface 7a composed of a flat surface formed at a position protruding from the mold match line 6 by 1 to 3 mm outward (2.7 mm in this embodiment). The reference surface 7a is a substantially vertical surface formed with a tilt angle of 1 to 5 ° with respect to the tube axis Z as a gradient from the mold (bottom mold). When the width (thickness) of the sealing end surface 8 formed at the large opening end 2 is a, and the protrusion dimension (maximum protrusion dimension) of the reference surface 7a from the mold match line 6 is b, b The value of / a is preferably 0.714 or less, more preferably 0.062 or more and 0.333 or less. Note that the end surface 7b on the large opening end 2 side of the positioning reference portion 7 is a flat surface extending outward from the mold match line 6, and this surface may be a polished surface.

  On the other hand, the connecting line C of the connecting portion 7c that gradually approaches the outer surface 4c of the body portion 4 from the end on the small opening end 3 side of the reference surface 7a of the positioning reference portion 7 has a shape as shown below. . That is, the connecting line C has a convex curve line C1 having a start point J1 smoothly connected to an end portion of the reference surface 7a on the small opening end 3 side and having a center of curvature on the inside thereof, and an outside of the body portion 4. It has a concave curved line C2 having an end point J4 smoothly connected to the side surface 4c and having a center of curvature on the outer side thereof, and an intermediate line L1 interposed between the two curved lines C1 and C2. The straight line LA connecting the connection point J2 between the convex curved line C1 and the intermediate line L1 and the connection point J3 between the concave curved line C2 and the intermediate line L is shifted to the outer side. Inclined at an angle θ1 of 2 ° or more and 25 ° or less with respect to a plane perpendicular to the tube axis Z (a plane indicated by a one-dot chain line in the same figure) having a directivity close to the large opening end 2 side. Yes.

  In this case, the convex curved line C1 is an arc having a radius of 1 mm or more and 3 mm or less and the intermediate line L1 is a tangent, and the concave curved line C2 has a radius of 10 mm or more and 20 mm or less. The intermediate line L1 is an arc having a tangent line. The total sum of the lengths of the two curved lines C1 and C2 is 50% or more of the total length of the connecting line C (60% or more in this embodiment). In addition, although the intermediate line L1 is a straight line in this embodiment, other than this, for example, it may be a convex or concave curved line having a larger radius of curvature than both curved lines C1 and C2.

  FIG. 3 is an enlarged vertical sectional view of an essential part illustrating a glass funnel for a cathode ray tube according to the second embodiment of the present invention, and FIG. 3 also omits hatching for convenience. The funnel 1A according to the second embodiment is different from the funnel 1 according to the first embodiment described above in that the convex curved line C3 and the concave curved line C4 are connected in a circumscribed state. A plane perpendicular to the tube axis Z (a dashed line in the figure) has a direction in which the tangent line LB between the curved lines C3 and C4 at the point J5 becomes closer to the large opening end 2A side as it moves outward. The surface is inclined at an angle θ2 of 2 ° or more and 25 ° or less. Since the dimensions and shapes of the other constituent elements are the same as those in the first embodiment, the same reference numerals are given to those constituent elements in FIG. When the convex curved line C3 and the concave curved line C4 are connected without being accurately circumscribed, the tangent of the convex curved line C3 and the tangent of the concave curved line C4 at the connection point do not match. However, even in such a case, the tangent lines of both of them are perpendicular to the tube axis Z, with the directionality toward the large opening end 2A as they move outward. It is inclined at an angle of 2 ° or more and 25 ° or less with respect to a flat surface (a surface indicated by an alternate long and short dash line in the drawing).

  Examples of the present invention will be described below, but the following Examples 1 to 15 and Comparative Examples 1 to 6 correspond to the funnel according to the first embodiment of the present invention described above. The following Examples 16 to 30 and Comparative Examples 7 to 12 correspond to the second embodiment of the present invention described above.

  First, as Examples 1 to 5 of the present invention, funnel molds having a maximum outer shape of about 510 mm and θ1 shown in FIG. 2 of 2 °, 10 °, 15 °, 20 °, and 25 ° are manufactured. At the same time, as Comparative Examples 1 and 2, funnel molds having the above θ1 of 1 ° and 27 ° were produced. Further, in this mold, the radius of the convex curve line C1 shown in the figure was 2 mm, the radius of the concave curve line C2 was 15 mm, and the intermediate line L1 was a straight line. Then, the funnel was press-molded using this mold, and the occurrence state of funnel defects during the molding was observed. The results are shown in Table 1 below. In Table 1, “◎” indicates extremely good, “◯” indicates good, and “×” indicates poor.

  According to Table 1 above, in Examples 1 to 5, deformation of the reference surface 7a (also referred to as alignment surface) of the positioning reference portion 7 and deformation or crack of the large opening end 2 (sealing end surface 8) occur. On the other hand, in Comparative Examples 1 and 2, there are many deformations of the reference surface 7a, or there are many deformations and cracks on the sealing end surface 8, which makes it unsuitable for production.

  Next, as Examples 6 to 10 of the present invention, funnel molds are produced in which the radius of the convex curve line C1 shown in FIG. 2 is 1 mm, 1.5 mm, 2 mm, 2.5 mm, and 3 mm. In addition, as Comparative Examples 3 and 4, funnel molds were prepared in which the radius of the convex curve line C1 was 0.5 mm and 3.5 mm. Further, in this mold, θ1 shown in the figure was 15 °, the radius of the concave curved line C2 shown in the figure was 15 mm, and the intermediate line L1 was a straight line. Then, the funnel was press-molded using this mold, and the occurrence state of funnel defects during the molding was observed. The results are shown in Table 2 below. In Table 2, “◎” indicates extremely good, “◯” indicates good, and “Δ” indicates poor wrinkle.

  According to Table 2 above, in Examples 6 to 10, the deformation of the reference surface 7a and the deformation or crack of the large opening end 2 (sealing end surface 8) did not occur, whereas Comparative Examples 3 and 4 It can be seen that the reference surface 7a is slightly deformed, or the sealing end surface 8 is slightly deformed and cracked, causing a slight defect in production.

  Next, as Examples 11 to 15 of the present invention, funnel molds in which the radius of the concave curved line C2 shown in FIG. 2 is 10 mm, 12 mm, 15 mm, 18 mm, and 20 mm are manufactured, and Comparative Example 5 is used. , 6, funnel molds were prepared in which the radius of the concave curved line C2 was 8 mm and 22 mm. Further, in this mold, θ1 shown in the figure was 15 °, the radius of the convex curved line C1 shown in the figure was 2 mm, and the intermediate line L1 was a straight line. Then, the funnel was press-molded using this mold, and the occurrence state of funnel defects during the molding was observed. The results are shown in Table 3 below. In Table 3, “◎” indicates extremely good, “◯” indicates good, and “Δ” indicates that wrinkle is poor.

  According to Table 3 above, in Examples 11 to 15, the deformation of the reference surface 7a and the deformation or crack of the large opening end 2 (sealing end surface 8) did not occur, whereas Comparative Examples 5 and 6 It can be seen that the reference surface 7a is slightly deformed, or the sealing end surface 8 is slightly deformed and cracked, causing a slight defect in production.

  Next, as Examples 16 to 20 of the present invention different from the above, the maximum outer shape is about 510 mm, and θ2 shown in FIG. 3 is 2 °, 10 °, 15 °, 20 °, and 25 °. A funnel mold was manufactured as Comparative Examples 7 and 8 so that the θ2 was 1 ° and 27 °. Further, in this mold, the radius of the convex curve line C3 shown in the figure was 2 mm, and the radius of the concave curve line C4 was 15 mm. Then, the funnel was press-molded using this mold, and the occurrence state of funnel defects during the molding was observed. The results are shown in Table 4 below. In Table 4, “◎” indicates extremely good, “◯” indicates good, and “×” indicates poor.

  According to Table 4 above, in Examples 16 to 20, the deformation of the reference surface 7a of the positioning reference portion 7 and the deformation or crack of the large opening end 2 (sealing end surface 8) did not occur. In Comparative Examples 7 and 8, there are many deformations of the reference surface 7a, or there are many deformations and cracks on the sealing end surface 8, which makes it unsuitable for production.

  Next, as Examples 21 to 25 of the present invention, funnel molds are produced in which the radius of the convex curve line C3 shown in FIG. 3 is 1 mm, 1.5 mm, 2 mm, 2.5 mm, and 3 mm. In addition, as Comparative Examples 9 and 10, funnel molds were prepared in which the radius of the convex curve line C3 was 0.5 mm and 3.5 mm. Further, in this mold, θ2 shown in the figure was 15 °, and the radius of the concave curved line C4 shown in the figure was 15 mm. Then, the funnel was press-molded using this mold, and the occurrence state of funnel defects during the molding was observed. The results are shown in Table 5 below. In Table 5, “◎” indicates very good, “◯” indicates good, and “Δ” indicates poor wrinkle.

  According to Table 5 above, in Examples 21 to 25, the deformation of the reference surface 7a and the deformation or crack of the large opening end 2 (sealing end surface 8) did not occur, whereas in Comparative Example 9, The reference surface 7a is slightly deformed, and in the comparative example 10, it can be seen that the sealing end surface 8 is slightly deformed and cracked, causing a slight defect in production.

  Next, as Examples 26 to 30 of the present invention, funnel molds in which the radius of the concave curved line C4 shown in FIG. 3 is 10 mm, 12 mm, 15 mm, 18 mm, and 20 mm are manufactured, and Comparative Example 11 is used. , 12, a funnel mold was prepared in which the radius of the concave curved line C4 was 8 mm and 22 mm. Further, in this mold, θ2 shown in the figure was 15 °, and the radius of the convex curved line C3 shown in the figure was 2 mm. Then, the funnel was press-molded using this mold, and the occurrence state of funnel defects during the molding was observed. The results are shown in Table 6 below. In Table 6, “◎” indicates extremely good, “◯” indicates good, and “Δ” indicates that wrinkle is poor.

  According to Table 6 above, in Examples 26 to 30, the deformation of the reference surface 7a and the deformation or crack of the large opening end 2 (sealing end surface 8) did not occur, whereas in Comparative Example 9, It can be seen that the reference surface 7a is slightly deformed, and in the comparative example 10, the sealing end surface 8 is slightly deformed and cracked, causing a slight defect in production.

1 is a perspective view showing an overall configuration of a glass funnel for a cathode ray tube according to a first embodiment of the present invention. It is a partial expanded longitudinal cross-sectional view (AA sectional view taken on the line of FIG. 1) which shows the principal part of the glass funnel for cathode ray tubes which concerns on 1st Embodiment of this invention. It is the elements on larger scale which show the principal part of the glass funnel for cathode-ray tubes which concerns on 2nd Embodiment of this invention. 4 (a), 4 (b), and 4 (c) are longitudinal front views showing a general funnel molding procedure. 5 (a) and 5 (b) are longitudinal sectional views showing a main part of a conventional cathode ray tube-like glass funnel.

Explanation of symbols

1 Funnel (glass funnel for cathode ray tube)
1A funnel (glass funnel for cathode ray tube)
2 Large opening end 3 Small opening end 4 Body part 4c Outside surface of body part 7 Positioning reference part 7a Reference surface (alignment surface)
7c Connecting part C Connecting line C1 Convex curved part C2 Concave curved part C3 Convex curved part C4 Concave curved part L1 Intermediate line LA straight line LB straight line

Claims (7)

A substantially funnel-shaped side wall portion formed with a substantially rectangular large opening end and a substantially circular small opening end is formed at one end and the other end in the tube axis direction, respectively, from the large opening end of the side wall portion to the small opening end side. A positioning reference part having a reference surface is formed in the body part facing, and a connecting part extending from the reference surface to the outer surface of the body part passes through the center part in the width direction of the reference surface and is parallel to the tube axis. As a contour of the cross section perpendicular to the reference plane, in a glass funnel for a cathode ray tube having a connecting line that gradually approaches the outer surface of the body part from the end on the small opening end side of the reference plane,
At least the outer surface of the connecting portion from the end on both sides in the width direction of the reference surface and the end on the small opening end side to the outer surface of the body portion is a press-molded surface, and the connecting line is From the end on the small opening end side of the reference surface, through the convex curve line having the center of curvature inward, the intermediate line, and the concave curve line having the center of curvature outward, the outside of the body part As the straight line connecting the connecting point between the convex curved line and the intermediate line and the connecting point between the concave curved line and the intermediate line moves smoothly outwards, A glass funnel for a cathode ray tube, characterized in that the glass funnel is inclined at an angle of 2 ° or more and 25 ° or less with respect to a plane perpendicular to the tube axis.   The glass funnel for a cathode ray tube according to claim 1, wherein the convex curved line is an arc having a radius of 1 mm or more and 3 mm or less.   3. The glass funnel for a cathode ray tube according to claim 1, wherein the concave curved line is an arc having a radius of 10 mm or more and 20 mm or less that circumscribes the outer surface of the body part. 4.   The glass funnel for a cathode ray tube according to any one of claims 1 to 3, wherein the intermediate line is substantially a straight line. A substantially funnel-shaped side wall portion formed with a substantially rectangular large opening end and a substantially circular small opening end is formed at one end and the other end in the tube axis direction, respectively, from the large opening end of the side wall portion to the small opening end side. A positioning reference part having a reference surface is formed in the body part facing, and a connecting part extending from the reference surface to the outer surface of the body part passes through the center part in the width direction of the reference surface and is parallel to the tube axis. As a contour of the cross section perpendicular to the reference plane, in a glass funnel for a cathode ray tube having a connecting line that gradually approaches the outer surface of the body part from the end on the small opening end side of the reference plane,
At least the outer surface of the connecting portion from the end on both sides in the width direction of the reference surface and the end on the small opening end side to the outer surface of the body portion is a press-molded surface, and the connecting line is From the end on the small opening end side of the reference surface to the outer surface of the body part smoothly through a convex curve line having a center of curvature inward and a concave curve line having a center of curvature outward. Directionality in which the tangent line of the convex curved line or the concave curved line at the connection point between the convex curved line and the concave curved line becomes closer to the large opening end side as it moves outward. And a glass funnel for a cathode ray tube, wherein the glass funnel is inclined at an angle of 2 ° or more and 25 ° or less with respect to a plane perpendicular to the tube axis.   6. The glass funnel for a cathode ray tube according to claim 5, wherein the convex curved line is an arc having a radius of 1 mm or more and 3 mm or less.   7. The glass funnel for a cathode ray tube according to claim 5, wherein the concave curved line is an arc having a radius of 10 mm or more and 20 mm or less circumscribing the outer surface of the body portion.

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