JP6834379B2 - Flat glass manufacturing method and flat glass manufacturing equipment - Google Patents

Description

The present invention relates to a method and an apparatus for producing flat glass from molten glass.

As is well known, for flat glass used in various fields, as represented by glass substrates for flat panel displays (FPD) such as liquid crystal displays (LCD), plasma displays (PDP), and organic EL displays (OLED). The reality is that strict product quality is required for surface defects and waviness.

In order to satisfy such a requirement, the down draw method is widely used as a method for manufacturing flat glass. As this down draw method, an overflow down draw method and a slot down draw method are known.

In the overflow down draw method, molten glass is poured into an overflow groove provided in the upper part of a molded body having a substantially wedge-shaped cross section, and the molten glass overflowing from the overflow groove on both sides is flowed along the side walls on both sides of the molded body. While flowing down, it is fused and integrated at the lower end of the molded body to continuously mold a single piece of flat glass. Further, in the slot down draw method, a slot-shaped opening is formed in the bottom wall of the molded body to which the molten glass is supplied, and the molten glass is allowed to flow down through the opening to continuously form a single plate glass. Is.

In particular, in the overflow down draw method, both the front and back surfaces of the molded flat glass are molded without contacting any part of the molded body during the molding process, so the fire surface is extremely flat and has no defects such as scratches. It becomes.

For example, as a plate glass manufacturing apparatus using an overflow down draw method, as disclosed in Patent Document 1, a molding furnace having a molded body inside, a slow cooling furnace installed below the molding furnace, and a slow cooling furnace provided below the slow cooling furnace are provided. Some are provided with a cooling part and a cutting part. In this flat glass manufacturing apparatus, molten glass overflows from the top of the molded body and is fused at the lower end to form flat glass (glass ribbon), and the flat glass is passed through a slow cooling furnace to remove its internal strain. After cooling to room temperature in the cooling part, it is configured to cut to a predetermined size in the cutting part. In the slow cooling furnace, a plurality of upper and lower rollers for pulling the plate glass formed by the molded body are arranged.

Japanese Unexamined Patent Publication No. 2012-197185

In the preparatory stage in the molding process by the molding furnace, the molten glass overflowing from the molded body is formed in a lump shape (hereinafter referred to as “glass lump”) at the lower end portion of the molded body. At the start of the molding process, it is necessary to efficiently perform the preparatory work of stretching the glass block and sandwiching it between the rollers in the slow cooling furnace.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a flat glass manufacturing method and a flat glass manufacturing apparatus capable of efficiently performing preparatory work for a molding process.

The present invention is for solving the above-mentioned problems, in which molten glass is allowed to flow down from a molded body to be molded as a plate glass, and is arranged below the molded body and separated in the width direction of the molded body. The flat glass is pulled by a plurality of upper and lower rollers including a set of first rollers and a set of second rollers arranged below the first rollers and separated in the width direction of the molded body. In the method of continuously producing the flat glass, at the start of the continuous production of the flat glass, a step of hanging a part of the molten glass from the molded body as a glass gob and the step of hanging the glass gob as a glass gob It is characterized by comprising a step of setting the separation distance of the first roller in the width direction to be smaller than the separation distance of the second roller in the width direction so as to be sandwiched by the first roller.

At the start of production of flat glass, that is, at the preparatory stage of the molding process, the glass block generated at the lower end of the molded body is formed at the center position in the width direction of the molded body. In this method, by setting the separation distance of the first roller in the width direction of the molded product to be smaller than the separation distance of the second roller, the glass gob can be reliably sandwiched by the first roller. The glass block is cooled by being sandwiched by the first roller, and as its width expands, it deforms into a plate shape. By sandwiching the plate-shaped deformed portion with the lower second roller, the width thereof can be further expanded, and a plate glass having a desired width can be formed. Due to the positional relationship between the first roller and the second roller, the preparatory work for the molding process can be efficiently performed.

In the above plate glass manufacturing method, the first roller may have a shaft portion that supports the first roller and may be configured to be movable in the axial direction of the shaft portion. According to this, by configuring the first roller so as to be movable in the axial direction, the position of the first roller can be adjusted according to the position and size of the glass gob. Therefore, the first roller can reliably hold the glass gob at a suitable position.

In the above-mentioned plate glass manufacturing method, it is desirable that the first roller moves to a position closer to the end in the width direction in the molded body so as to be in the same position as the second roller after sandwiching the glass gob. .. According to this, the first roller can guide the glass gob to the second roller side, and the glass gob can be sandwiched by the second roller at an early stage.

Further, after the second roller sandwiches the end portion of the plate glass, it is desirable that the first roller separates so as not to come into contact with the plate glass. By separating the first roller from the plate glass in a state where the plate glass having a predetermined width is continuously formed by the second roller, the plate glass can be stably towed by the second roller without suddenly changing the temperature of the plate glass. ..

In the above-mentioned method for producing flat glass, it is desirable that the pressure at which the first roller holds the glass gob is set to be larger than the pressure at which the second roller holds the flat glass. According to this, the glass gob can be reliably sandwiched by the first roller, and the width of the glass gob can be suitably expanded so that a part of the glass gob faces the second roller.

In the above plate glass manufacturing method, the second roller has a shaft portion that supports the second roller, and the length of the shaft portion of the first roller is the length of the shaft portion of the second roller. It is desirable to set it longer than the length. By forming the shaft portion of the first roller long in this way, the moving range of the first roller in the axial direction can be made as large as possible. Therefore, the first roller can reliably sandwich the glass gob according to the size and position of the glass gob that changes depending on the size of the flat glass, the temperature condition, and the like.

In the flat glass manufacturing method, it is desirable that the width of the first roller is set larger than the width of the second roller. According to this, the first roller can surely hold the glass gob. Further, the first roller has an improved ability to cool the glass gob, and the sandwiched glass gob can be effectively expanded in the direction of the second roller.

The present invention is for solving the above-mentioned problems, in which a part of the molten glass is hung as a glass block, and a molded body for molding the molten glass as a plate glass and a molded body arranged below the molded body. In a plate glass manufacturing apparatus including a plurality of upper and lower rollers for pulling the plate glass, the rollers are arranged below the molded body and separated from each other in the width direction of the molded body. The first roller includes a roller and a set of second rollers arranged below the first roller and separated in the width direction of the molded body, and the glass gob is sandwiched by the first roller. It is characterized by having a structure in which the separation distance of one roller in the width direction is set smaller than the separation distance of the second roller in the width direction.

In the preparatory stage of the molding process, the glass gob formed at the lower end of the molded body is formed at the center position in the width direction of the molded body. In the above-mentioned flat glass manufacturing apparatus, by setting the separation distance of the first roller in the width direction of the molded body to be smaller than the separation distance of the second roller, the glass gob can be reliably sandwiched by the first roller. When the glass gob sandwiched by the first roller is cooled by the first roller, its width is gradually extended and sandwiched by the second roller. As a result, the flat glass can be continuously formed while maintaining a predetermined width. Due to the positional relationship between the first roller and the second roller, the flat glass manufacturing apparatus can efficiently perform the preparatory work for the molding process.

According to the present invention, the preparatory work for the molding process can be efficiently performed.

It is a front view of the flat glass manufacturing apparatus. It is a side view of the flat glass manufacturing apparatus. It is sectional drawing of a roller and a shaft part. It is a front view of the flat glass manufacturing apparatus which shows one process of a flat glass manufacturing method. It is a front view of the flat glass manufacturing apparatus which shows one process of a flat glass manufacturing method. It is a side view of the flat glass manufacturing apparatus which shows one process of the flat glass manufacturing method. It is a front view of the flat glass manufacturing apparatus which shows one process of a flat glass manufacturing method. It is a front view of the flat glass manufacturing apparatus which shows one process of a flat glass manufacturing method. It is a side view of the flat glass manufacturing apparatus which shows one process of the flat glass manufacturing method.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. 1 to 9 show an embodiment of a flat glass manufacturing method and a flat glass manufacturing apparatus according to the present invention.

As shown in FIGS. 1 and 2, the plate glass manufacturing apparatus 1 mainly includes a molding furnace 2 and a slow cooling furnace 3 located below the molding furnace 2. The plate glass manufacturing apparatus 1 forms the molten glass GM supplied from the melting furnace provided on the upstream side into the plate glass GR by the molding furnace 2, and then removes the internal strain of the plate glass GR in the slow cooling furnace 3.

The molding furnace 2 includes a molded body 4 that executes an overflow down draw method inside the furnace wall, and an edge roller 5 that pulls out the molten glass GM overflowing from the molded body 4 as a plate glass GR.

The molded body 4 is formed in an elongated shape and has an overflow groove 6 formed at the top along the longitudinal direction thereof. Further, the molded body 4 includes a vertical surface portion 7 and an inclined surface portion 8 that form a pair of side wall portions facing each other. An inclined surface portion 8 is formed so as to be connected to the lower end portion of the vertical surface portion 7. The pair of inclined surface portions 8 intersect with each other by gradually approaching downward to form the lower end portion 9 of the molded body 4.

As shown in FIG. 1, the edge rollers 5 are configured as a pair on the left and right in front view so as to sandwich the end portions GRa and GRb in the width direction X in the plate glass GR immediately below the molded body 4. Further, as shown in FIG. 2, the edge roller 5 is configured as a roller pair arranged side by side in the plate thickness direction Y of the plate glass GR so as to sandwich the end portions GRa and GRb in the width direction X of the plate glass GR. .. In the following, the longitudinal direction of the molded body 4 is referred to as a "width direction", and a common reference numeral X is used for the width direction of the molded body 4 and the width direction of the plate glass GR (FIGS. 1, FIG. 4, FIG. 5, FIG. 7 and FIG. 8).

In this molding furnace 2, the molten glass GM is poured into the overflow groove 6 of the molded body 4, and the molten glass GM overflowing from the overflow groove 6 on both sides is allowed to flow down along the vertical surface portion 7 and the inclined surface portion 8 at the lower end portion. It is fused and integrated in step 9 to continuously form a single flat glass GR. The molded body 4 is not limited to the above configuration, and may be configured to execute the slot down draw method.

As shown in FIGS. 1 and 2, the slow cooling furnace 3 has rollers (anneal rollers) 10 to 13 configured as a plurality of stages (four stages in the example) in the vertical direction. Hereinafter, these plurality of stages of rollers 10 to 13 will be referred to as first rollers 10 to fourth rollers 13 in order from the top. As shown in FIG. 2, each of the rollers 10 to 13 is configured as a roller pair that sandwiches the plate glass GR in the plate thickness direction Y. Further, the rollers 10 to 13 are configured to form a pair on the left and right in the front view (see FIG. 1) so as to sandwich the end portions GRa and GRb in the width direction X in the plate glass GR.

Each of the rollers 10 to 13 individually includes shaft portions 10a to 13a that support the rollers 10 to 13. Each of the rollers 10 to 13 is a cantilever roller supported by one end of each of the shaft portions 10a to 13a. The length L1 of the shaft portion 10a of the first roller 10 is set to be longer than the lengths L2 to L4 of the shaft portions 11a to 13a of the other rollers 11 to 13. The shaft portions 11a to 13a of the second roller 11, the third roller 12, and the fourth roller 13 are configured so that their lengths L2 to L4 are equal.

As shown in FIG. 3, cooling devices 14 are provided on the shaft portions 10a to 13a of the rollers 10 to 13. The cooling device 14 has a cooling pipe 15 arranged inside the shaft portions 10a to 13a which are formed in a hollow shape. The cooling pipe 15 has a port portion 15a for discharging a cooling medium such as air. The cooling medium discharged from the mouth portion 15a cools the shaft portions 10a to 13a and the rollers 10 to 13 by flowing through the shaft portions 10a to 13a.

Each of the rollers 10 to 13 paired in the plate thickness direction Y of the plate glass GR is configured so that the distance between the axes can be changed. Further, the rollers 10 to 13 are configured to be movable along the axial direction thereof, that is, the width direction X in the molded body 4 or the plate glass GR. Hereinafter, the direction from the end portions 4a and 4b of the molded body 4 toward the central portion 4c is referred to as "inward in the axial direction", and the direction from the central portion 4c toward the end portions 4a and 4b is referred to as "outward in the axial direction".

The width W1 of the first roller 10 is configured to be larger than the widths W2 to W4 of the other rollers 11 to 13. The width W2 of the second roller 11, the width W3 of the third roller 12, and the width W4 of the fourth roller 13 are configured to be equal to each other.

The first roller 10 is mainly for sandwiching the glass gob GL formed by the molten glass GM overflowing from the molded body 4 in the molding preparatory step of the plate glass GR. When the glass gob GL sandwiched by the first roller 10 is deformed to form a plate, the second roller 11 to the fourth roller 13 sandwich a part of the glass block GL and have a predetermined width. It is for sandwiching the end portions GRa and GRb in the width direction X in.

Hereinafter, a method of molding the flat glass GR by the flat glass manufacturing apparatus 1 having the above configuration (flat glass manufacturing method) will be described. At the start of manufacturing the flat glass GR, it is necessary to perform the work of sandwiching the molten glass GM flowing down from the molded body 4 between the rollers 5, 10 to 13 (preparatory work of the molding process). That is, the molten glass GM supplied from the melting furnace is injected into the overflow groove 6 of the molded body 4, overflows from the overflow groove 6, travels along the vertical surface portion 7 and the inclined surface portion 8, and joins at the lower end portion 9. To do. At this time, the pair of left and right edge rollers 5 sandwich a part of the molten glass GM that merges and is about to fall (hang down) (see FIG. 4). In the present invention, the time when the production of the flat glass GR is started means a case where the preparatory work of the molding process of the flat glass GR is required. It shall also include the case of.

As shown in FIG. 4, the molten glass GM forms a glass gob GL at the central portion 4c of the width direction X in the molded body 4. The glass block GL periodically falls (hangs down) from the molded body 4 a plurality of times. The first roller 10 stands by at a position closer to the ends 4a and 4b in the width direction X of the molded body 4. In this standby position, the first roller 10 is in the same position as the other rollers 11 to 13 in the width direction X. Therefore, the separation distance D1 of the first roller 10 is equal to the separation distances D2 to D4 of the other rollers 11 to 13.

When the glass gob GL is formed, as shown in FIG. 5, the first roller 10 moves from the standby position toward the position (initial holding position) closer to the central portion 4c in the width direction X in the molded body 4. The glass gob GL is sandwiched (a step of sandwiching the glass gob GL by the first roller 10). In this case, as shown in FIG. 6, the first roller 10 which is a pair of rollers approaches each other (indicated by the alternate long and short dash line) to sandwich the glass gob GL in the middle of falling (hanging).

Here, since the width of the glass gob GL is smaller than the width of the plate glass GR to be molded later, the first roller 10 is located at a position closer to the central portion 4c of the molded body 4, that is, the width of the plate glass GR to be molded later. It is arranged at a position closer to GRc in the central portion of the direction X. In other words, the separation distance D1 in the axial direction (width direction X) of the first roller 10 which is a pair of left and right in front view is larger than the separation distance D2 to D4 in the axial direction of the left and right sets of the other rollers 11 to 13. Also becomes smaller (see FIG. 5).

The size of the glass gob GL changes depending on the size and temperature conditions of the plate glass GR to be molded. Therefore, the separation distance D1 of the first roller 10 is adjusted by moving in the axial direction. The paired first rollers 10 in the plate thickness direction Y of the plate glass GR are set so that the pressure for sandwiching the glass gob GL is larger than the pressure for the other rollers 11 to 13 to sandwich the plate glass GR.

The first roller 10 cools by sandwiching the glass gob GL and expands the width of the glass gob GL. As shown in FIG. 7, the first roller 10 moves outward in the axial direction from a position closer to the central portion 4c of the molded body 4 so as to correspond to such expansion of the glass gob GL. Along with this, the width of the glass gob GL is further expanded. As a result, the glass block GL approaches the second roller 11.

The second roller 11, which is a pair of left and right, moves inward in the axial direction in order to sandwich a part of the glass gob GL. As a result, the second rollers 11 come close to each other, and the separation distance D2 becomes smaller. At this time, the separation distance D2 of the second roller 11 is set so as to be substantially equal to or slightly larger than the separation distance D1 of the first roller 10. After that, the second roller 11 sandwiches a part of the glass gob GL expanded by the first roller 10. When the second roller 11 sandwiches a part of the glass gob GL, it returns to the original position (the separation distance D2 becomes large again). Due to such an operation of the first roller 10 and the second roller 11, the width of the glass gob GL is widened and gradually deformed into a plate shape. Along with this, the molten glass GM on the upstream side (upper side) connected to the glass block GL is also formed into a plate shape while expanding its width.

The glass gob GL whose width is further expanded by the second roller 11 reaches the third roller 12. As a result, the third roller 12 sandwiches a part of the glass gob GL and guides it downward. After that, the fourth roller 13 sandwiches a part of the glass gob GL and guides it downward (see FIG. 8). As described above, the plate-shaped molten glass GM connected to the glass block GL by being sandwiched between the second roller 11 to the fourth roller 13 further expands the width, and as a result, the plate glass GR having the desired width. Will be towed by the second roller 11 to the fourth roller 13 (see FIG. 1).

When the molten glass GM is formed into a plate glass GR having a predetermined width, the second roller 11 to the fourth roller 13 sandwich the end portions GRa and GRb in the width direction X in the plate glass GR in the width direction X ( In the axial direction), they are separated by a constant separation distance D2 to D4 (see FIG. 1). In this case, the separation distances D2 to D4 are set to be equal, but are not limited to this, and may be set to be different depending on the state of the flat glass GR.

When the plate glass GR is sandwiched by the second roller 11 to the fourth roller 13, the first roller 10 releases the sandwiching of the plate glass GR. That is, as shown in FIG. 9, the pair of first rollers 10 have a large inter-axis distance and are separated from the flat glass GR. As a result, the first roller 10 does not come into contact with the plate glass GR, so that the plate glass GR is not cooled by the first roller 10. After that, the first roller 10 may be moved outward in the axial direction to be further separated from the flat glass GR. In this case, the separation distance D1 of the pair of left and right first rollers 10 may be larger than the separation distances D2 to D4 of the other rollers 11 to 13.

According to the flat glass manufacturing apparatus 1 and the flat glass manufacturing method according to the present embodiment described above, the first roller 10 is placed below the molded body 4 at the start of manufacturing the flat glass GR (during the preparatory work of the molding process). By arranging the molded body 4 at a position closer to the central portion 4c in the width direction X (a position closer to the central portion GRc in the width direction in the plate glass GR), the separation distance D1 of the first roller 10 is set to the separation distance of the second roller 11. Set smaller than D2. As a result, the glass gob GL generated in the preparatory stage of the molding process can be reliably sandwiched.

The glass gob GL is cooled by being sandwiched by the first roller 10, and as its width expands, it deforms into a plate shape. By sandwiching the plate-shaped deformed portion by the lower second roller 11, the width of the molten glass GM can be further expanded, and a plate glass GR having a desired width can be formed. As a result, the flat glass manufacturing apparatus 1 and the flat glass manufacturing method can efficiently perform the preparatory work for the molding process.

Further, by configuring the first roller 10 to be movable in the axial direction, the position of the first roller 10 can be adjusted according to the generation position and size of the glass gob GL. Therefore, the first roller 10 can surely hold the glass gob GL at a suitable position. Further, the first roller 10 moves outward in the axial direction so as to be in the same position as the second roller 11 after sandwiching the glass gob GL. By moving the first roller 10 to a position closer to the ends 4a and 4b in the width direction X in the molded body 4, the glass gob GL is guided to the second roller 11 side, and the glass gob GL is quickly seconded. It can be sandwiched between the rollers 11.

Further, after the second roller 11 sandwiches the end portions GRa and GRb of the plate glass GR, the first roller 10 is separated so as not to come into contact with the plate glass GR, so that the cooling effect of the first roller 10 is not exerted on the plate glass GR. , The plate glass GR having a uniform thickness can be suitably pulled by the second roller 11 to the fourth roller 13. Further, since the pressure at which the first roller 10 sandwiches the glass gob GL is set to be larger than the pressure at which the second roller 11 holds the flat glass GR, the glass gob GL having a thickness larger than that of the flat glass GR is first used. It can be securely sandwiched by the roller 10. Moreover, the first roller 10 makes it possible to suitably expand the width of the glass gob GL so that a part of the glass gob GL faces the second roller 11.

Further, by setting the length L1 of the shaft portion 10a of the first roller 10 to be longer than the lengths L2 to L4 of the shaft portions 11a to 13a of the second roller 11 to the fourth roller 13, the first roller 10 The range of movement in the axial direction can be made as large as possible. Further, by shortening the lengths of the shaft portions 11a to 13a of the second roller 11 to the fourth roller 13, the misalignment of the second roller 11 to the fourth roller 13 is minimized, and the flat glass GR is preferably pulled. Becomes possible.

By setting the width W1 of the first roller 10 to be larger than the widths W2 to W4 of the other rollers 11 to 13, the ability to securely sandwich the glass gob GL in the first roller 10 and cool the glass gob. Can be improved.

The present invention is not limited to the configuration of the above embodiment, and is not limited to the above-mentioned action and effect. The present invention can be modified in various ways without departing from the gist of the present invention.

In the above embodiment, an example in which the first roller 10 is moved outward in the axial direction after sandwiching the glass gob GL is shown, but the present invention is not limited to this. The first roller 10 may remain in that position with the glass gob GL sandwiched between them.

In the above embodiment, an example is shown in which the first roller 10 and the second roller 11 are moved in the axial direction to sandwich the glass gob GL, but the present invention is not limited to this, and the third roller 12 and the fourth roller 13 may be moved in the axial direction so that the glass gob GL is sandwiched between them.

1 Flat glass manufacturing equipment 4 Molded body 10 First roller 10a Shaft of first roller
11 2nd roller 11a 2nd roller shaft GL glass block GM molten glass GR plate glass L1 1st roller shaft length L2 2nd roller shaft length W1 1st roller width W2 2nd roller width

Claims (8)

A set of first rollers arranged below the molded body and separated in the width direction of the molded body, and below the first roller, while molten glass is allowed to flow down from the molded body to form a flat glass. In a method for continuously producing the flat glass by pulling the flat glass by a plurality of upper and lower rollers including a set of second rollers arranged in the molded body and separated from each other in the width direction of the molded body.
At the start of continuous production of the flat glass
A step of hanging a part of the molten glass from the molded body as a glass block,
A step of setting the separation distance of the first roller in the width direction to be smaller than the separation distance of the second roller in the width direction so that the glass gob is sandwiched by the first roller.
A plate glass manufacturing method comprising a step of deforming the glass gob into a plate shape by sandwiching it between the first roller and the second roller. The plate glass manufacturing method according to claim 1, wherein the first roller has a shaft portion that supports the first roller and is configured to be movable in the axial direction of the shaft portion. The plate glass manufacturing method according to claim 2, wherein the first roller moves to a position closer to the end in the width direction in the molded body so as to be in the same position as the second roller after sandwiching the glass gob. .. The plate glass manufacturing method according to claim 1 or 2, wherein after the second roller sandwiches an end portion of the plate glass in the width direction , the first roller separates so as not to come into contact with the plate glass. The plate glass manufacturing method according to any one of claims 1 to 4, wherein the pressure at which the first roller sandwiches the glass gob is set to be larger than the pressure at which the second roller sandwiches the plate glass. The second roller has a shaft portion that supports the second roller, and has a shaft portion.
The plate glass manufacturing method according to claim 2 or 3, wherein the length of the shaft portion of the first roller is set longer than the length of the shaft portion of the second roller. The plate glass manufacturing method according to any one of claims 1 to 6, wherein the width of the first roller is set to be larger than the width of the second roller. A plate glass including a molded body in which a part of the molten glass hangs down as a glass block and the molten glass is molded as a plate glass, and a plurality of upper and lower rollers arranged below the molded body and pulling the plate glass. In the manufacturing equipment
The rollers are a set of first rollers arranged below the molded body and separated in the width direction of the molded body, and are arranged below the first roller and in the width direction of the molded body. Including a set of second rollers separated in
The distance in the width direction before Symbol first roller, have a structure in which smaller than the distance in the width direction of the second roller,
It said first roller and said second roller, said glass gob by sandwiching a is configured to be able to deform in a plate shape, characterized in Rukoto, flat glass manufacturing apparatus.

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