JP2021195295A - Manufacturing apparatus for glass article and method of manufacturing the same - Google Patents

Abstract

To suppress the devitrification of a molten glass on lower ends of both end parts in a width direction of a molding while maintaining the temperature distribution of a glass ribbon uniform.SOLUTION: A molding apparatus 1 comprises: a molding 2 that allows a molten glass Gm to flow down; a regulation member 7 disposed on both end parts in a width direction of the molding 2, and having a regulation surface 11 that regulates both end pats in the width direction of the molten glass Gm that flows down the molding 2; and a heater 16 disposed on the outer side in the width direction from the regulation surface 11 and only on the lower part of the regulation member 7.SELECTED DRAWING: Figure 1

Description

The present invention relates to an improvement in a technique for manufacturing a glass article by an overflow down draw method.

As a method for manufacturing a glass article such as a glass plate, an overflow down draw method may be used. In this process, the molding apparatus comprises a substantially wedge-shaped molded body. The molten glass supplied to the molded body overflows from the groove formed at the top of the molded body, and then joins at the lower end portion along the inclined molded surfaces formed on both side surfaces of the molded body. As a result, a strip-shaped glass ribbon is continuously formed from the molten glass. According to this manufacturing method, since the front and back surfaces of the glass ribbon to be molded do not come into contact with the molded body during the molding process, there is an advantage that a smooth glass ribbon without scratches or the like can be molded on the front and back surfaces (for example, Patent Document 1, Patent Document 1, See 2).

Japanese Unexamined Patent Publication No. 2012-214349 Japanese Unexamined Patent Publication No. 2013-216533

In the case of the overflow down draw method, the molten glass may be cooled to cause devitrification at the lower ends of both ends in the width direction of the molded body, and a devitrified substance may be formed. The devitrified material grows over time and can be an obstacle obstructing the flow path of the molten glass. When the devitrified material grows to become an obstacle, a part of the molten glass separates from the main flow of the molten glass along the devitrified material, and is cooled and solidified while hanging from the lower end of the molded body. May form a ball. If the glass ball falls, it may cause serious troubles such as damage to the manufacturing apparatus and the glass ribbon.

Patent Document 2 discloses that the entire regulating member (guide) arranged at both ends in the width direction of the molded body is energized and heated from the viewpoint of suppressing devitrification of the molten glass. However, when the entire regulating member is energized and heated, the temperature at both ends of the molten glass in the width direction rises too much. As a result, the temperature distribution of the glass ribbon formed from the molten glass becomes non-uniform, and wrinkles may occur on the glass ribbon.

An object of the present invention is to suppress devitrification of molten glass at the lower ends of both ends in the width direction of a molded body while maintaining a uniform temperature distribution of the glass ribbon.

The present invention, which was devised to solve the above problems, is a manufacturing apparatus for a glass article provided with a molding apparatus for molding a glass ribbon from molten glass by an overflow downdraw method. A regulating member arranged at both ends in the width direction of the body and the molded body and having a regulating surface for regulating both ends in the width direction of the molten glass flowing down the molded body, and a lower portion of the regulating member outside the regulating surface in the width direction. It is characterized by having a heater arranged only in the glass.

By doing so, since only the lower part of the regulating member is heated, both ends in the width direction of the molten glass flowing down the molded body are not excessively heated. That is, it is possible to suppress devitrification of the molten glass at the lower ends of both ends in the width direction of the molded body while maintaining a uniform temperature distribution of the glass ribbon molded from the molten glass.

In the above configuration, the heater is preferably a resistance heating type heater.

By doing so, the calorific value and the heating portion can be adjusted by adjusting the thickness and width of the heater, so that the required portion can be efficiently heated.

When the heater is a resistance heating type, the heater is provided in a large portion having a first cross-sectional area and a narrow portion having a second cross-sectional area smaller than the first cross-sectional area and provided below the large portion. It is preferable to have.

By doing so, the calorific value of the narrow portion having a small cross-sectional area and a large resistance value is larger than the calorific value of the large portion having a large cross-sectional area and a small resistance value, so that the lower end portion of the molded body is prone to devitrification. Can be heated intensively.

In the above configuration, it is preferable that an insulating layer made of a thermal spray film is formed between the regulating member and the heater.

By doing so, it is possible to insulate between the heater and the regulating member without obstructing the heat conduction from the heater to the regulating member, so that the lower part of the regulating member can be efficiently heated.

In the above configuration, it is preferable that the molded body has a pair of inclined molded surfaces that intersect each other at the lower end of the molded body, and the heater is arranged only at a position corresponding to the inclined molded surface.

By doing so, it is possible to more reliably prevent both ends of the molten glass flowing down the molded body in the width direction from being excessively heated.

In the above configuration, the restricting member has a first portion that stands up from the inclined molded surface and has a regulated surface, and a second portion along the inclined molded surface, and the heater is arranged in the second portion. preferable.

In many cases, the area of the second part of the regulating member can be made larger than the area of the first part, so that it becomes easy to secure a space for arranging the heater. Further, when both ends of the molded body in the width direction are fitted and fixed to the regulating member, the heat of the heater can be easily transferred to the inclined molded surface of the molded body.

When the heater is arranged in the second portion, the heater is arranged in the second portion along one of the pair of inclined molded surfaces and the second portion along the other of the pair of inclined molded surfaces, respectively. Is preferable.

By doing so, it becomes easy to transfer the heat of the heater to each of the pair of inclined molded surfaces of the molded body.

When arranging the heater in the second part, the heater provided in the second part along one of the pair of inclined molded surfaces and the heater provided in the second part along the other of the pair of inclined molded surfaces. It is preferable that and are continuous at the lower end portion of the molded body.

By doing so, it is possible to efficiently heat the lower end portion of the molded product in which devitrification of the molten glass is likely to occur.

In the above configuration, the heater is preferably welded to the regulatory member at only one location.

By doing so, the heater can be reliably fixed to the regulating member while preventing electric leakage from the heater to the regulating member.

In the above configuration, the heater is preferably welded to the lower end of the regulatory member.

In this way, the heater can be securely fixed to the regulating member. Further, since the heater can be surely brought into close contact with the regulating member around the lower end portion of the molded body, the lower end portion of the molded body where devitrification of the molten glass is likely to occur can be efficiently heated.

The present invention, which was invented to solve the above problems, is a method for manufacturing a glass article, which comprises a molding step of molding a glass ribbon from molten glass by an overflow downdraw method using a molding device. It is provided with a molded body through which the molten glass flows down and a regulating member arranged at both ends in the width direction of the molded body and having a regulating surface for regulating both ends in the width direction of the molten glass flowing down the molded body, and is regulated in the molding process. It is characterized in that the regulating member is heated by a heater arranged only in the lower part of the regulating member on the outside in the width direction with respect to the surface.

By doing so, it is possible to enjoy the same effect as the corresponding configuration described above.

According to the present invention, it is possible to suppress devitrification of molten glass at the lower ends of both ends in the width direction of the molded product while maintaining a uniform temperature distribution of the glass ribbon.

It is a front view which shows the molding apparatus included in the manufacturing apparatus of the glass article which concerns on one Embodiment of this invention. FIG. 3 is a sectional view taken along the line AA of the molding apparatus shown in FIG. It is BB sectional view of the molding apparatus shown in FIG. It is an enlarged view which shows the Q area of FIG. 3 enlarged. It is an enlarged view which shows the P area of FIG. 1 enlarged. It is an enlarged view which shows the modification of the P region of FIG. 1 in an enlarged manner. It is BB sectional view of the modification of the molding apparatus shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the orthogonal coordinate system consisting of XYZ shown in the figure, the X direction and the Y direction are the horizontal direction, and the Z direction is the vertical direction. Further, the direction corresponding to the width direction of the glass ribbon G to be molded is called the width direction X, and the direction corresponding to the thickness direction of the glass ribbon G to be molded is called the thickness direction Y.

As shown in FIGS. 1 and 2, the apparatus for manufacturing a glass article according to the present embodiment forms a molten glass Gm supplied from a melting furnace (not shown) into a strip-shaped glass ribbon G by an overflow downdraw method. The molding apparatus 1 is provided.

The molding apparatus 1 includes a molded body 2 arranged inside a molding chamber (not shown). Below the molding chamber, the molding apparatus 1 has a slow cooling chamber for slowly cooling (annealing) the glass ribbon G, a cooling chamber for cooling the glass ribbon G, and a glass ribbon G for obtaining a glass plate as a glass article. It is further equipped with a cutting chamber for cutting the glass into a predetermined size. The obtained glass plate is used, for example, as a glass substrate or a cover glass for a display.

The molded body 2 is formed of a long refractory material along the width direction X of the glass ribbon G to be molded. In the present specification, the width direction of the molded body 2 means the same direction as the width direction X of the glass ribbon G to be molded.

A groove portion (overflow groove) 3 formed along the width direction X is provided on the top portion of the molded body 2. A supply pipe (not shown) is connected to one end side of the groove portion 3 in the width direction X. The molten glass Gm is supplied into the groove 3 through this supply pipe. The method of supplying the molten glass Gm is not limited to this. For example, the molten glass Gm may be supplied from both ends of the groove portion 3 in the width direction X, or the molten glass Gm may be supplied from above the groove portion 3.

The molded body 2 has a symmetrical shape in the thickness direction Y. Both outer surfaces 4 in the thickness direction Y of the molded body 2 are connected to a vertical forming surface 5 forming a planar shape along the vertical direction and below the vertical forming surface 5, respectively, and form a planar shape inclined with respect to the vertical direction. It is provided with an inclined forming surface 6. Each vertically formed surface 5 is a surface parallel to each other. Each inclined molded surface 6 is a surface inclined so as to approach each other in the thickness direction Y as it goes downward. That is, the molded body 2 has a wedge shape that tapers downward when viewed from the width direction X by forming each inclined molded surface 6, and the corner portion where the inclined molded surfaces 6 intersect is the molded body 2. The lower end portion 2a of the above is formed. The shape of the vertically formed surface 5 may be changed to an inclined surface, a curved surface, or the like, or may be omitted.

As shown in FIGS. 1 and 2, regulatory members 7 for regulating the spread of the molten glass Gm flowing down the vertical forming surface 5 and the inclined forming surface 6 are provided at both ends of the molded body 2 in the width direction X, respectively. ing.

The regulating member 7 is formed of, for example, platinum or a platinum alloy.

The regulating member 7 is fixed to both ends of the molded body 2 in the width direction X in a state of being externally fitted. Specifically, the end portion of the molded body 2 in the width direction X is fitted into the fitting recess 8 provided in the regulating member 7. The method of fixing the regulating member 7 is not limited to this. For example, the regulating member 7 may be fixed to the molded body 2 by a pin or the like.

In the present embodiment, the regulating member 7 has a first portion 9 rising from the outer surface 4 of the molded body 2 and a second portion 10 along the outer surface 4 of the molded body 2. Specifically, the first portion 9 has an upper portion of the first portion 9 rising from the vertical molding surface 5 of the molded body 2 and a lower portion of the first portion 9 rising from the inclined molded surface 6 of the molded body 2. Similarly, the second portion 10 has an upper portion of the second portion 10 along the vertical forming surface 5 of the molded body 2 and a lower portion of the second portion 10 along the inclined forming surface 6 of the molded body 2.

The inner end surface of the first portion 9 in the width direction X is a regulation surface 11 that comes into contact with the end surface of the molten glass Gm flowing down the outer surface 4 of the molded body 2 in the width direction X. The regulation surface 11 is formed of a plane that is perpendicular to the vertical forming surface 5 and the inclined forming surface 6 and extends straight downward. That is, the regulation surface 11 is a plane along the YZ plane.

As shown in FIGS. 1 and 2, a part of the lower end portion 2a of the molded body 2 (the lower end portion 6a of the inclined molded surface 6) is covered from below at the lower portions of both ends of the molded body 2 in the width direction X. Each of the guide members 12 is provided. The guide member 12 has a role of guiding a part of the molten glass Gm that normally flows down the inclined molded surface 6 of the molded body 2 along the inclined molded surface 6, and from a gap between the molded body 2 and the regulating member 7. The molten glass Gm that has entered the fitting recess 8 is discharged in the F direction at the lower end 2a of the molded body 2 and merges with the molten glass Gm that normally flows down along the inclined molded surface 6 of the molded body 2. Have.

The guide member 12 is made of the same material as the regulation member 7 (for example, platinum or a platinum alloy).

The guide member 12 has a vertical guide surface 13 along the regulation surface 11 of the regulation member 7, an inclined guide surface 14 along the inclined molding surface 6 of the molded body 2, and an inclined guide surface 14 at the lower end portion 2a of the molded body 2. It has fins 15 hanging from. The fin 15 is a plate-like body extending along the vertical direction Z.

The guide member 12 is a single member in which the vertical guide surface 13, the inclined guide surface 14, and the fins 15 are integrated. In the present embodiment, the guide member 12 is fixed to the regulation member 7 by welding the vertical guide surface 13 to the regulation surface 11 of the regulation member 7. The method of fixing the guide member 12 is not limited to this. For example, the guide member 12 may be fixed to the inclined molded surface 6.

The inclined guide surface 14 has a V shape that follows the shape of the lower end portion 2a of the molded body 2, and covers a part of the lower end portion 2a and a part of each inclined molded surface 6. Further, the inclined guide surface 14 is formed so that the dimension in the width direction X becomes longer toward the lower end side of the guide member 12.

The thickness of the vertical guide surface 13 is, for example, 0.5 to 3 mm. The thickness of the inclined guide surface 14 is, for example, 0.5 to 3 mm. The thickness of the fin 15 is, for example, 0.5 to 10 mm, and the dimension of the fin 15 in the width direction X is, for example, 10 to 100 mm.

In the present embodiment, the fins 15 are provided only at both ends in the width direction of the lower end portion 6a of the inclined molded surface 6, but the fins 15 are not limited thereto. For example, the fins 15 may be provided in the entire area of the lower end portion 6a of the inclined forming surface 6. Alternatively, the fin 15 may be omitted.

As shown in FIGS. 1 and 3, a heater 16 is provided below the regulation member 7 outside the regulation surface 11 in the width direction X. By doing so, since only the lower portion of the regulating member 7 is heated, both ends of the molten glass Gm flowing down the molded body 2 in the width direction X are not excessively heated. Therefore, it is possible to suppress devitrification of the molten glass Gm at the lower ends 2a of both ends of the molded body 2 in the width direction X while maintaining the temperature distribution of the glass ribbon G uniformly.

Here, the lower portion of the regulating member 7 is preferably a position corresponding to the inclined molded surface 6 of the molded body 2. In the present embodiment, the heater 16 is arranged only at the position corresponding to the inclined molded surface 6 of the molded body 2, and is not arranged at the position corresponding to the vertical molded surface 5 of the molded body 2.

The heater 16 is a resistance heating type heater. The heat generating portion (conductive portion) of the heater 16 is formed of, for example, platinum, a platinum alloy, nichrome, iron chromium, carbon, or silicon carbide.

In this embodiment, the heater 16 is arranged on the lower surface of the second portion 10 of the regulatory member 7.

The heater 16 is provided at a wide portion 17 (wide portion) having a first width W1 and a narrow portion 18 having a second width W2 smaller than the first width W1 and provided at a position below the wide portion 17. It has (narrow part). The wide portion 17 and the narrow portion 18 are strips along the lower surface of the second portion 10. By doing so, the calorific value of the narrow portion 18 having a small cross-sectional area and a large resistance value is larger than the calorific value of the wide portion 17 having a large cross-sectional area and a small resistance value, so that devitrification is likely to occur. The lower end portion 2a of 2 can be heated intensively.

(Cross-sectional area of narrow portion) / (cross-sectional area of wide portion) is preferably, for example, 0.1 to 0.8, and more preferably 0.3 to 0.5. Further, (dimension L2 of the narrow portion in the direction along the inclined forming surface 6) / ((dimension of the inclined forming surface 6 in the direction along the inclined forming surface 6) + (vertical forming in the direction along the vertical forming surface 5) The dimensions of the surface 5)) are preferably, for example, 0.01 to 0.3, more preferably 0.1 to 0.2. (Dimension L1 of the vast portion in the direction along the inclined forming surface 6) / ((Dimension of the inclined forming surface 6 in the direction along the inclined forming surface 6) + (Vertical forming surface 5 in the direction along the vertical forming surface 5) Dimensions)) are, for example, preferably 0.01 to 0.3, and more preferably 0.1 to 0.2. When the heater 16 is provided with a wide portion and a narrow portion, the width may be constant and the thickness may be different, or both the width and the thickness may be different. Further, the heater 16 may have a constant cross-sectional area.

As shown in FIG. 3, the heater 16 is arranged in the second portion 10 along one of the pair of inclined molded surfaces 6 and the second portion 10 along the other of the pair of inclined molded surfaces 6, respectively. ing. The heater 16 arranged in the second portion 10 along one inclined molded surface 6 and the heater 16 arranged in the second portion 10 along the other inclined formed surface 6 are continuous at the lower end portion 2a of the molded body 2. is doing. That is, the heater 16 is a continuous strip-shaped body, and the continuous portion 19 has a V-shape that imitates the lower end portion 6a of the inclined molded surface 6.

As shown in FIG. 4, an insulating layer 20 made of a thermal spray film is formed on the surface of the second portion 10 of the regulating member 7, and the insulating layer 20 is in contact with the heater 16. The insulating layer 20 may be formed in the entire arrangement area of the heater 16 or may be partially formed in the arrangement area of the heater 16 as long as the insulation between the regulation member 7 and the heater 16 can be maintained. good. In the present embodiment, the insulating layer 20 is formed on substantially the entire surface of the second portion 10. By forming the insulating layer 20 made of a thermal spray film in this way, it is possible to insulate between the heater 16 and the regulating member 7 without obstructing the heat conduction from the heater 16 to the regulating member 7. The lower part of 7 can be heated efficiently.

The insulating layer 20 is formed of, for example, an alumina / zirconia sprayed film, an alumina sprayed film, or a zirconia sprayed film.

The insulating layer 20 may be formed on the surface of the heater 16 instead of the surface of the regulating member 7. Alternatively, the insulating layer 20 may be omitted.

As shown in FIG. 5, the heater 16 is fixed to the first portion 9 of the regulating member 7 by welding. The welded portion 21 between the heater 16 and the regulating member 7 is formed only at one location on the regulating member 7. The insulating layer 20 is not formed on the welded portion 21. By doing so, the heater 16 can be reliably fixed to the regulation member 7 while preventing the regulation member 7 from being energized.

In FIG. 5, the welded portion 21 is formed at the lower end portion 7a of the regulating member 7, but is not limited thereto. That is, the welded portion 21 may be formed at any one position above the lower end portion 7a of the regulating member 7. However, when the welded portion 21 is formed on the lower end portion 7a of the regulating member 7, the heater 16 can be reliably brought into close contact with the regulating member 7 around the lower end portion 2a of the molded body 2. Therefore, the lower end portion 2a of the molded body 2 in which devitrification of the molten glass Gm is likely to occur can be efficiently heated. Therefore, it is preferable that the welded portion 21 is formed at the lower end portion 7a of the regulating member 7.

When the welded portion 21 is formed at the lower end portion 7a of the regulating member 7, the welded portion 21 may be formed at two or more locations (two locations in the illustrated example) as shown in FIG. This is because if the lower end portion 7a of the regulation member 7 is used, the lower end portion 7a of the regulation member 7 can be heated even if the heater 16 energizes the regulation member 7.

The welded portion 21 is formed of the same material (for example, platinum, platinum alloy, etc.) as the heat generating portion of the regulating member 7 and the heater 16.

The method for manufacturing a glass article according to the present embodiment includes a molding step of molding a glass ribbon G from molten glass Gm by an overflow down draw method using the above-mentioned molding apparatus 1. In the molding step, the molten glass Gm supplied to the groove portion 3 overflows from the groove portion 3 and then travels along each outer surface 4 and joins at the lower end portion 2a of the molded body 2. As a result, the glass ribbon G is continuously formed from the molten glass Gm.

The present invention is not limited to the configuration of the above-described embodiment, nor is it limited to the above-mentioned effects. The present invention can be modified in various ways without departing from the gist of the present invention.

In the above embodiment, one end and the other end of the heater 16 are positioned above the lower end 2a of the molded body 2, and the central portion (continuous portion 19) of the heater 16 is located around the lower end 2a of the molded body 2. Although the aspect of positioning has been described, the arrangement of the heater 16 is not limited to this. For example, as an embodiment in which one end and the other end of the heater 16 are positioned around the lower end portion 2a of the molded body 2, and the central portion (continuous portion 19) of the heater 16 is positioned above the lower end portion 2a of the molded body 2. May be good. Further, the heater 16 is arranged in the heater 16 arranged in the second portion 10 along one inclined molded surface 6 and the second portion 10 along the other inclined formed surface 6 without providing the continuous portion 19. The heater 16 may be an independent circuit.

As shown in FIG. 7, the heater 16 may be arranged on the outer end surface (the end surface on the side not in contact with the molten glass Gm) 22 in the width direction of the first portion 9 of the regulating member 7. Also in this configuration, the heater 16 may have a wide portion 17 (wide portion) and a narrow portion 18 (narrow portion) provided at a position below the wide portion 17 (wide portion).

The heater 16 is not limited to the resistance heating type heater. For example, the heater 16 may be an energization heating type heater, an induction heating type heater, or the like.

In the above embodiment, the guide member 12 may be omitted.

In the above embodiment, the case where the glass article is a glass plate has been described, but the glass article may be, for example, a glass roll in which the glass ribbon G is wound around a winding core or the like in a roll shape.

1 Molding device 2 Molding body 4 Outer side surface 5 Vertical forming surface 6 Inclined forming surface 7 Restricting member 8 Fitting recess 9 First part 10 Second part 11 Restricting surface 12 Guide member 13 Vertical guide surface 14 Inclining guide surface 15 Fin 16 Heater 17 Wide part (large part)
18 Narrow part (narrow part)
19 Continuous part 20 Insulation layer 21 Welded part

Claims (11)

In a glass article manufacturing apparatus provided with a molding apparatus for forming a glass ribbon from molten glass by an overflow down draw method.
The molding apparatus is a regulating member having a molded body through which the molten glass flows down and a regulating surface which is arranged at both ends in the width direction of the molded body and regulates both ends in the width direction of the molten glass flowing down the molded body. A device for manufacturing a glass article, which comprises a heater arranged only on the lower portion of the restricting member, which is outside the regulation surface in the width direction. The device for manufacturing a glass article according to claim 1, wherein the heater is a resistance heating type heater. 2. The heater has a vast portion having a first cross-sectional area and a narrow portion provided below the vast portion and having a second cross-sectional area smaller than the first cross-sectional area. The equipment for manufacturing glass articles according to the above. The apparatus for manufacturing a glass article according to any one of claims 1 to 3, wherein an insulating layer made of a thermal spray film is formed between the regulating member and the heater. The molded body has a pair of inclined molded surfaces that intersect each other at the lower end of the molded body.
The apparatus for manufacturing a glass article according to any one of claims 1 to 4, wherein the heater is arranged only at a position corresponding to the inclined molded surface. The regulating member has a first portion that stands up from the inclined molded surface and has the restricted surface, and a second portion along the inclined molded surface.
The device for manufacturing a glass article according to claim 5, wherein the heater is arranged in the second portion. The sixth aspect of claim 6, wherein the heater is arranged in the second portion along one of the pair of inclined molded surfaces and the second portion along the other of the pair of inclined molded surfaces. Glass article manufacturing equipment. The heater arranged in the second portion along one of the pair of inclined molded surfaces and the heater arranged in the second portion along the other of the pair of inclined molded surfaces
The apparatus for manufacturing a glass article according to claim 7, which is continuous at the lower end of the molded body. The device for manufacturing a glass article according to any one of claims 1 to 8, wherein the heater is welded to the regulated member at only one place. The device for manufacturing a glass article according to any one of claims 1 to 9, wherein the heater is welded to the lower end portion of the regulating member. In a method for manufacturing a glass article, which comprises a molding step of molding a glass ribbon from molten glass by an overflow downdraw method using a molding apparatus.
The molding apparatus is a restricting member having a molded body through which the molten glass flows down and a regulating surface which is arranged at both ends in the width direction of the molded body and has contact with both ends in the width direction of the molten glass flowing down the molded body. And with
A method for manufacturing a glass article, characterized in that, in the molding step, the regulated member is heated by a heater arranged only in the lower portion of the regulated member on the outer side in the width direction from the regulated surface.

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