JP2022161680A - Apparatus and method for manufacturing glass plate - Google Patents

Abstract

To provide an apparatus and method for manufacturing a glass plate, capable of preventing the surface of a support roller from deteriorating with heat from a glass ribbon and reducing manufacturing cost by achieving long life.SOLUTION: An apparatus 1 for manufacturing a glass plate includes: a molding furnace 2 for molding molten glass Gm into a glass ribbon Gr; a slow cooling furnace 3 for slowly cooling the glass ribbon Gr; a cooling chamber 4 for radiationally cooling the glass ribbon Gr; and a cutting chamber 5 for cutting the glass ribbon Gr into a predetermined length to obtain a glass plate G. The cooling chamber 4 includes a support roller 41 contacting the glass ribbon Gr and a cooler for cooling the surface of the support roller 41.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to an improvement in a glass plate manufacturing apparatus and a glass plate manufacturing method.

As is well known, methods using down-draw methods such as the overflow down-draw method, slot down-draw method, redraw method, and methods using the float method are widely adopted as methods for manufacturing glass sheets. It is In particular, the overflow down-draw method is known as a method capable of obtaining a glass sheet with very small surface waviness and roughness and excellent surface quality.

In the overflow down-draw method, a molded body having a wedge-shaped cross section placed in a molding furnace is used, and molten glass is continuously supplied to a groove provided on the top of the molded body. The supplied molten glass overflows from the groove, flows down along both side surfaces of the molded body, and fuses at the lower end of the molded body to form a plate-like glass ribbon. Both edges of the glass ribbon are nipped and pulled by a plurality of pulling rollers, so that the glass ribbon is transported on a transport path extending vertically in the annealing furnace. At this time, since the ambient temperature in the slow cooling furnace is controlled, the glass ribbon is subjected to the slow cooling treatment, and unintended thermal strain is suppressed from occurring in the glass ribbon. Since the temperature of the glass ribbon in the slow cooling furnace is high, high heat resistance is required for the tension rollers that hold the glass ribbon. To this end, the surface of the pulling roller is made from an inorganic material containing ceramic fibers and a binder. Subsequently, the glass ribbon is allowed to cool by being transported on a conveying path extending into a cooling chamber arranged at the bottom of the slow cooling furnace. After that, the glass ribbon is transported to a cutting chamber and cut in the width direction for each predetermined length to obtain a glass plate.

In recent years, glass plates for displays are becoming larger. As the width dimension of the glass ribbon increases, the weight of the glass ribbon transported on the transport path increases. The weight of the ribbon excessively pulls the molten glass in the vicinity of the molded body, and a phenomenon may occur in which the glass ribbon breaks and falls. The glass ribbon is sandwiched between a plurality of tension rollers, and as described above, the tension rollers are made of inorganic material and have a small coefficient of friction with the glass ribbon. For this reason, it is easy for slippage to occur with the glass ribbon, and the role of adjusting the transfer speed of the glass ribbon cannot be sufficiently fulfilled. In order to prevent such a phenomenon, Patent Document 1 discloses a method of nipping the glass ribbon by installing support rollers made of a material (for example, synthetic rubber) having a large coefficient of friction with the glass ribbon in the cooling chamber. ing.

JP 2012-167014 A

However, if the strain point of the glass becomes high, the temperature of the glass ribbon carried into the cooling chamber also becomes high, and the amount of heat conducted from the glass ribbon to the support rollers increases. Further, even if the transfer speed of the glass ribbon is increased in order to improve the manufacturing efficiency, the amount of heat conducted from the glass ribbon to the support roller increases. Therefore, even if the surface of the support roller is made of highly heat-resistant rubber such as fluororubber or silicone rubber, the surface of the support roller deteriorates due to heat in a relatively short period of time, requiring frequent replacement. there were.

SUMMARY OF THE INVENTION An object of the present invention is to prevent the surface of a support roller from deteriorating due to heat from a glass ribbon, thereby prolonging the life of the support roller, thereby reducing manufacturing costs.

The present invention, which has been devised to solve the above problems, comprises a forming furnace for forming molten glass into a glass ribbon, an annealing furnace for slowly cooling the glass ribbon, a cooling chamber for allowing the glass ribbon to cool, and a glass ribbon. A glass sheet manufacturing apparatus comprising: a cutting chamber for cutting into a predetermined length to obtain a glass sheet; A device is provided. By directly cooling the surface of the support roller with the cooling device, deterioration of the surface of the support roller due to heat can be suppressed and the life of the support roller can be extended. As a result, the replacement frequency of the support rollers can be reduced, and the manufacturing cost can be reduced.

Said structure WHEREIN: It is preferable that the said cooling device cools the surface of the said support roller from the outside. If the surface of the support roller is made of a material with low thermal conductivity (such as rubber), the surface cannot be efficiently cooled from inside the support roller. By cooling the surface of the support roller from the outside, the surface of the support roller can be efficiently cooled regardless of the material of the surface of the support roller.

In the above configuration, the support rollers constitute a support roller group by arranging a plurality of the support rollers side by side along the longitudinal direction of the glass ribbon, and the cooling device is the support roller group in the support roller group. It is preferably provided on the support roller that contacts the portion of the glass ribbon at 200° C. or higher. According to such a configuration, it is possible to selectively cool only the support roller having a high surface temperature and a high deterioration rate among the plurality of support rollers. As a result, the number of cooling devices installed can be reduced, and equipment costs can be reduced.

In the above configuration, the surface material of the support roller is preferably rubber. Since rubber has a large coefficient of friction against glass, a large frictional force can be obtained with a small contact pressure. Therefore, the contact pressure of the supporting rollers against the glass ribbon can be reduced, and breakage of the glass ribbon can be prevented. Furthermore, since the physical properties of rubber, such as hardness, flexibility, and surface smoothness, can be easily adjusted, a material capable of reliably supporting the glass ribbon can be easily obtained.

In the above configuration, the heat resistance temperature of the rubber is preferably 200° C. or higher. According to such a configuration, it is possible to reduce the number of support rollers whose surfaces are heated to the heat-resistant temperature or more by coming into contact with the glass ribbon. As a result, the number of cooling devices installed can be reduced, and equipment costs can be reduced. Here, the heat resistant temperature means the maximum temperature within the range where the physical properties at room temperature can be maintained as they are without deformation of the rubber due to heat and unnecessary stickiness due to heat.

Said structure WHEREIN: It is preferable that the said cooling device is a cooling roller contact|abutted on the surface of the said support roller. As a cooling device for cooling the surface of the support roller, there are a cooling roller, a cooling plate, and a cooling device that are brought into contact with the surface of the support roller. When a cooling plate is provided, friction between the surface of the supporting roller and the cooling plate causes wear of the surface of the supporting roller and an increase in the torque required to rotate the supporting roller. When a coolant blowing device is provided, air currents are generated in the glass sheet manufacturing apparatus, which causes problems such as disturbance of the ambient temperature and scattering of glass powder. The surface of the support roller can be cooled without causing such a problem by using the configuration in which the cooling roller is brought into contact.

Said structure WHEREIN: It is preferable that the said cooling roller has the flow path which distribute|circulates a coolant inside. According to such a configuration, the heat conducted from the surface of the support roller to the cooling roller can be rapidly conducted to the coolant. Therefore, the surface of the support roller that contacts the cooling roller can be efficiently cooled.

Said structure WHEREIN: It is preferable that the said refrigerant|coolant is a coolant. With such a configuration, the surface of the support roller that contacts the cooling roller can be cooled more efficiently.

Said structure WHEREIN: It is preferable that the said glass ribbon is 2000 mm or more in width. With such a configuration, the weight of the glass ribbon increases, and slippage between the support roller and the support roller is likely to occur. Therefore, the effect that the support roller prevents the glass ribbon from slipping becomes remarkable.

Further, the method for manufacturing a glass plate according to the present invention includes a forming step of forming molten glass into a glass ribbon, a slow cooling step of slowly cooling the glass ribbon, and allowing the glass ribbon to cool while being in contact with a support roller. A glass plate manufacturing method comprising a cooling step and a cutting step of cutting the glass ribbon into a predetermined length to obtain a glass plate, wherein the cooling step includes cooling the surface of the support roller using a cooling device. Characterized by cooling. Since the surface of the support roller comes into contact with the hot glass ribbon, it heats up and deteriorates in a relatively short period of time. By directly cooling the surface of the support roller with the cooling device, deterioration of the surface of the support roller due to heat can be suppressed and the life of the support roller can be extended. As a result, the replacement frequency of the support rollers can be reduced, and the manufacturing cost can be reduced.

According to the present invention, the manufacturing cost can be reduced by efficiently cooling the surface of the support roller and extending the life of the support roller.

FIG. 1 is a front view showing a glass plate manufacturing apparatus according to one embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line AA of FIG. FIG. 3 is a perspective view showing a main part of a support roller according to one embodiment of the invention. FIG. 4 is a cross-sectional view showing a cooling roller according to one embodiment of the invention. 5 is a cross-sectional view taken along the line BB of FIG. 4. FIG. FIG. 6 is a cross-sectional view showing a cooling roller according to another embodiment of the invention. FIG. 7 is a side view showing essential parts of a support roller and a cooling device according to another embodiment of the invention.

EMBODIMENT OF THE INVENTION Hereinafter, according to an accompanying drawing, the manufacturing apparatus of the glass plate which concerns on this invention, and one Embodiment of the manufacturing method of a glass plate are described.

As shown in FIGS. 1 and 2, a glass plate manufacturing apparatus 1 according to the present embodiment includes a forming furnace 2 for forming molten glass Gm into a glass ribbon Gr, an annealing furnace 3 for slowly cooling the glass ribbon Gr, a glass A cooling chamber 4 for cooling the ribbon Gr and a cutting chamber 5 for cutting the glass ribbon Gr to a predetermined length to obtain a glass plate G are provided. Moreover, the manufacturing apparatus 1 of a glass plate is used for execution of the manufacturing method of the glass plate which concerns on this embodiment.

The molding furnace 2 is a space surrounded by a furnace wall 11 and includes a molded body 21 having a wedge-shaped cross section and a set of edge rollers 22 provided below the molded body 21 . In the molding furnace 2 , the molten glass Gm is continuously supplied to the groove provided on the top 211 of the molding 21 . This molten glass Gm is formed, for example, by heating and melting frit and cullet in a melting furnace, and is subjected to clarification and stirring as necessary.

The supplied molten glass Gm overflows from the groove, flows down along both side surfaces 212 of the molded body 21 , and fuses at the lower end portion 213 of the molded body 21 . Thereby, a plate-like glass ribbon Gr is formed. Both edges of the glass ribbon Gr are cooled while being sandwiched from the front and back sides by a set of four edge rollers 22 . This minimizes shrinkage in the width direction of the glass ribbon Gr.

The slow cooling furnace 3 is a space surrounded by a furnace wall 11 and has a plurality of pairs of tension rollers 31 . A plurality of pulling rollers 31 are arranged along the longitudinal direction of the glass ribbon Gr, and pull the glass ribbon Gr downward while pulling it in the width direction so that the glass ribbon Gr does not shrink in the width direction due to surface tension or the like. The interior of the slow cooling furnace 3 is set to have a predetermined temperature gradient by a heater (not shown). The temperature of the glass ribbon Gr gradually decreases as it is transferred through the slow cooling furnace 3, and is slowly cooled to a temperature below the strain point. Thereby, it is possible to suppress the occurrence of unintended thermal strain inside the glass ribbon Gr.

The pull roller 31 is made from an inorganic material containing ceramic fibers and binders. The roller shaft of the tension roller 31 is connected to a power source (for example, a motor) (not shown) and controlled to rotate at a constant speed (peripheral speed or number of revolutions). In the present embodiment, three pairs of tension rollers 31 are arranged along the longitudinal direction of the glass ribbon Gr, but the present invention is not limited to this. Depending on the temperature and width of the glass ribbon Gr, the transfer speed, the size of the annealing furnace 3, and the like, the number of pairs of the pulling rollers 31 may be two or less or four or more. Also, the roller shaft of the pulling roller 31 may be controlled to rotate with a constant torque.

The cooling chamber 4 includes support rollers 41, and the support rollers 41 constitute a support roller group 41A by arranging a plurality of pairs of support rollers 41 side by side along the longitudinal direction of the glass ribbon Gr. A plurality of pairs of support rollers 41 transport the glass ribbon Gr downward while sandwiching both edges of the glass ribbon Gr from the front and back. The cooling chamber 4 cools the glass ribbon Gr without a heater. The width of the glass ribbon Gr is preferably 2000 mm or more, more preferably 2500 mm or more, and even more preferably 3000 mm or more. When the width of the glass ribbon Gr is large in this way, the self-weight of the glass ribbon Gr increases, and slippage between the support roller 41 and the support roller 41 is likely to occur. Therefore, the effect that the support roller 41 prevents the glass ribbon Gr from slipping becomes remarkable.

As shown in FIG. 3 , the support roller 41 has a rubber surface layer 413 attached to a metal shaft 411 via a metal core 412 . The surface layer portion 413 contacts the glass ribbon Gr and corresponds to the surface of the support roller 41 of the present invention. Synthetic rubber such as silicone rubber or fluororubber can be used as the material of the surface layer portion 413 . The heat resistance temperature of the rubber of the surface layer portion 413 is preferably 200° C. or higher, more preferably 250° C. or higher, and even more preferably 300° C. or higher. The shaft portion 411 is connected to a power source (for example, a motor) (not shown) and controlled to rotate at a constant speed (peripheral speed or number of revolutions). In this embodiment, four pairs of support rollers 41 are arranged along the longitudinal direction of the glass ribbon Gr, but this is not the only option. Depending on the temperature and width of the glass ribbon Gr, the transport speed, the size of the cooling chamber 4, and the like, the logarithm of the support rollers 41 may be 3 pairs or less or 5 pairs or more. Also, the shaft portion 411 of the support roller 41 may be controlled to rotate with a constant torque.

The cutting chamber 5 has a cutting mechanism (not shown) that cuts the cooled glass ribbon Gr in the width direction at every predetermined length to obtain the glass plate G. The obtained glass sheet G is conveyed to subsequent processes such as a removing process for cutting and removing both ends of the glass sheet G in the width direction, various inspection processes, and a packing process by a conveying device (not shown). Thus, the glass plate G is manufactured.

As shown in FIGS. 1 and 2 , the cooling chamber 4 of this embodiment includes a cooling roller 42 as a cooling device for cooling the surface of the support roller 41 .

As shown in FIGS. 4 and 5, the cooling roller 42 includes a roller portion 421 that contacts the surface of the support roller 41, a shaft portion 425 that holds the roller portion 421, and a cooling liquid Lc (for example, water) circulating therein. and a channel 422 that allows The roller portion 421 is held by a shaft portion 425 via a bearing 426 and is rotatable as the support roller 41 rotates. Further, the roller portion 421 is made of a metal material such as stainless steel, so that the heat conducted from the surface of the support roller 41 to the roller portion 421 can be quickly conducted to the cooling liquid Lc. The bearing 426 is provided with a sealing structure to prevent leakage of the coolant Lc. The channel 422 is connected to an inflow channel 423 and an outflow channel 424 provided inside the shaft portion 425 . As shown in FIG. 5, an inflow passage 423 may be provided on one side of the shaft portion 425 in the longitudinal direction, and an outflow passage 424 may be provided on the opposite side of the shaft portion 425. As shown in FIG. A double pipe structure may be provided on one side, and the inflow path 423 and the outflow path 424 may be provided on one side. The cooling liquid Lc is supplied from a cooling liquid source (not shown) to the flow path 422 through the inflow path 423 . After cooling the roller portion 421 in the channel 422 , the coolant Lc is discharged through the outflow channel 424 .

According to the above-described glass plate manufacturing apparatus and glass plate manufacturing method, the surface of the support roller 41 can be efficiently cooled by the cooling device (cooling roller 42), so that the life of the support roller 41 can be extended. It can be extended, and by lowering the replacement frequency, the manufacturing cost can be reduced.

As shown in FIGS. 1 and 2, of the support roller group 41A arranged along the longitudinal direction of the glass ribbon Gr, the support roller 41 that contacts the portion of the glass ribbon Gr at 200° C. or higher has a support roller A cooling roller 42 is preferably provided in contact with the surface of 41 . With such a configuration, it is possible to reduce the number of cooling devices to be installed, thereby reducing equipment costs. In the present embodiment, the cooling rollers 42 are provided on the three pairs of support rollers 41 from above among the plurality of pairs of support rollers 41, but the present invention is not limited to this. Depending on the temperature and transfer speed of the glass ribbon Gr carried into the cooling chamber 4, the number of pairs of support rollers 41 with which the cooling rollers 42 are brought into contact may be two pairs or less or four pairs or more.

In this embodiment, the cooling roller 42 is brought into contact with the support roller 41 from above, but the cooling roller 42 may be brought into contact with the support roller 41 from below, from the side, or from an oblique direction. From the standpoint of protecting the support roller 41 from falling glass fragments when the glass ribbon Gr is broken, it is preferable to bring the cooling roller 42 into contact with the support roller 41 from above.

When the surface of the support roller 41 deteriorates, the torque required to rotate the support roller 41 at a constant speed changes. Therefore, it is preferable to monitor the deterioration state of the surface of the support roller 41 by measuring the torque of the power source connected to the shaft portion 411 and detecting the temporal change of the torque. When a motor is used as the power source, the torque of the motor can be measured by measuring the load current of the motor using a sensor.

In addition, the present invention is not limited to the configuration of the above-described embodiment, nor is it limited to the above-described effects. Various modifications can be made to the present invention without departing from the gist of the present invention.

In the above embodiment, the case where the present invention is applied to manufacture of a glass plate by the overflow down-draw method has been described, but the present invention is not limited thereto. The present invention can also be applied to other glass plate manufacturing methods such as a slot down-draw method, in which sheet drawing is performed while pulling the glass ribbon Gr using rollers.

Although the cooling liquid Lc is used as the coolant in the above embodiment, the present invention is not limited to this, and a cooling gas may be used. From the viewpoint of efficiently cooling the support roller 41, it is preferable to use the cooling liquid Lc.

In the above embodiment, the surface of the support roller 41 is cooled by bringing the cooling roller 42 into contact with it, but the present invention is not limited to this. As shown in FIG. 7, a cooling plate 43 may be brought into contact with the surface of the support roller 41 as a cooling device, or a duct 44 for blowing cooling gas Gc onto the surface of the support roller 41 may be used as a cooling device. When the cooling plate 43 is brought into contact with the support rollers 41 from above, the support rollers 41 can be protected from falling objects when the glass ribbon Gr is damaged in the transport path. Also, a flow path for circulating a coolant may be provided inside the cooling plate 43 . Also, the cooling device may be configured by combining the cooling roller 42 , the cooling plate 43 and the duct 44 .

In the above-described embodiment, the shaft portion 411 is shared by the two support rollers 41 that are in contact with both edges of the glass ribbon Gr, and both ends of the shaft portion 411 are supported. , the two support rollers 41 may each be provided with a shaft portion 411, and the shaft portion 411 may be cantilevered. Similarly, in the above embodiment, the two tension rollers 31 in contact with both edges of the glass ribbon Gr have a common roller shaft, and both ends of the roller shaft are supported. A roller shaft may be provided for each of the two tension rollers 31 described above, and the roller shaft may be supported by a cantilever.

In the above embodiment, one shaft 411 is provided with two core portions 412 and surface layer portions 413 to support both edge portions of the glass ribbon Gr, but the present invention is not limited to this. Three or more core portions 412 and surface layer portions 413 may be provided on one shaft portion 411 to support both edge portions and an intermediate portion of the glass ribbon Gr. With such a configuration, the contact area between the support roller 41 and the glass ribbon Gr can be increased, so the glass ribbon Gr can be supported with a smaller contact pressure.

INDUSTRIAL APPLICABILITY The present invention can be suitably used to reduce manufacturing costs by efficiently cooling the surface of the support roller and extending the life of the support roller.

1 manufacturing apparatus 2 forming furnace 3 annealing furnace 4 cooling chamber 41 support roller 41A support roller group 42 cooling roller 422 flow path 5 cutting chamber Gr glass ribbon Gm molten glass Lc cooling liquid

Claims (10)

A forming furnace for forming the molten glass into a glass ribbon, an annealing furnace for slowly cooling the glass ribbon, a cooling chamber for allowing the glass ribbon to cool, and a cutting chamber for cutting the glass ribbon into a predetermined length to obtain a glass plate. A glass plate manufacturing apparatus comprising:
The apparatus for manufacturing a glass plate, wherein the cooling chamber includes a support roller that contacts the glass ribbon, and a cooling device that cools the surface of the support roller. 2. The glass plate manufacturing apparatus according to claim 1, wherein the cooling device cools the surface of the support roller from the outside. The support rollers constitute a support roller group by arranging a plurality of the support rollers side by side along the longitudinal direction of the glass ribbon,
3. The apparatus for manufacturing a glass sheet according to claim 1, wherein the cooling device is provided on the support roller that is in contact with a portion of the glass ribbon having a temperature of 200[deg.] C. or higher in the group of support rollers. 4. The apparatus for manufacturing a glass sheet according to claim 1, wherein the material of the surface of said support roller is rubber. 5. The apparatus for manufacturing a glass plate according to claim 4, wherein the heat resistant temperature of the rubber is 200[deg.] C. or higher. 6. The apparatus for manufacturing a glass sheet according to claim 1, wherein the cooling device is a cooling roller that contacts the surface of the support roller. 7. The apparatus for manufacturing a glass plate according to claim 6, wherein the cooling roller has a channel for circulating a coolant therein. 8. The glass plate manufacturing apparatus according to claim 7, wherein the coolant is a cooling liquid. The glass plate manufacturing apparatus according to any one of claims 1 to 8, wherein the glass ribbon has a width of 2000 mm or more. A forming step of forming molten glass into a glass ribbon, a slow cooling step of slowly cooling the glass ribbon, a cooling step of allowing the glass ribbon to cool while being in contact with a support roller, and cutting the glass ribbon into a predetermined length. A glass plate manufacturing method comprising a cutting step of obtaining a glass plate,
A method for manufacturing a glass sheet, wherein in the cooling step, the surface of the support roller is cooled using a cooling device.

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