WO2014185131A1

WO2014185131A1 - Device for manufacturing glass sheet and method for manufacturing glass sheet

Info

Publication number: WO2014185131A1
Application number: PCT/JP2014/056041
Authority: WO
Inventors: 伊賀　元一; 信之伴
Original assignee: 旭硝子株式会社
Priority date: 2013-05-16
Filing date: 2014-03-07
Publication date: 2014-11-20
Also published as: JPWO2014185131A1; CN105050970B; CN105050970A; JP6103048B2; KR20160007483A; KR102153290B1

Abstract

A device for manufacturing a glass sheet, for supplying molten glass onto a molten metal (S) in a float bath (20) from an inflow port of the float bath (20), spreading a glass ribbon (G) in a width direction through use of a support roll (40) inserted from both sides of the float bath (20) in a molding region of the float bath (20), and molding the glass ribbon (G) to a predetermined thickness, wherein a glass ribbon delivery mechanism (70) is provided having drive rolls (71A-71C) for delivering the glass ribbon (G) in a downstream direction to an annealing region (L3) between a molding region (L2) and a float bath exit (29). The glass ribbon delivery mechanism (70) causes the drive rolls (71A-71C) to contact edge parts of the glass ribbon (G) on both sides thereof in the width direction and drives the drive rolls (71A-71C) so that the edge parts on both sides are delivered in the downstream direction.

Description

Glass plate manufacturing apparatus and glass plate manufacturing method

The present invention relates to a glass plate manufacturing apparatus and a glass plate manufacturing method.

The float method is widely used as a glass plate forming method. The float method is a method in which molten glass introduced on a molten metal (for example, molten tin) accommodated in a bathtub is caused to flow in a predetermined direction to form a strip-shaped glass ribbon. The glass ribbon is gradually cooled in the process of flowing in the horizontal direction, then pulled up from the molten metal by a lift-out roll, and gradually cooled in a slow cooling furnace to become a sheet glass. The plate-like glass is unloaded from the slow cooling furnace and then cut into a predetermined size and shape by a cutting machine to become a glass plate as a product.

By the way, the glass ribbon in a state thinner than the equilibrium thickness tends to shrink in the width direction. If the shrinkage is excessive, the thickness of the product glass plate becomes thicker than the target thickness.

Therefore, conventionally, in order to suppress shrinkage in the width direction of the glass ribbon, a support roll for supporting the glass ribbon has been used (for example, see Patent Document 1). A plurality of pairs of support rolls are arranged on both sides of the glass ribbon in the width direction, and tension is applied to the glass ribbon in the width direction.

The support roll has a rotating member in contact with the surface of the glass ribbon at the tip. The rotating member has a disk shape, for example, and has a gear-shaped uneven portion on the outer periphery. As the convex portions of the concave and convex portions bite into the glass ribbon, the shrinkage of the glass ribbon is suppressed.

In a glass plate manufacturing apparatus, a glass ribbon that flows on a molten metal stored in a float bath is molded into a predetermined thickness.

JP 2011-225386 A

By the way, in recent years, it has been demanded to reduce the thickness of the glass plate, and particularly in the case of a glass plate for a display substrate, it is preferably 0.7 mm or less, more preferably 0.5 mm or less, and further preferably 0.3 mm. In the following, a glass plate of 0.2 mm or less, more preferably 0.1 mm or less is desired.

The glass ribbon is transported downstream by the rotation of a lift-out roll and a transport roll disposed behind the float bath outlet. Therefore, in the float bath, a tensile force in the downstream direction is applied to the glass ribbon by the lift-out roll and the transport roll, and the glass ribbon is transported.

On the other hand, in the glass plate manufacturing apparatus, when a relative speed difference occurs between the moving speed of the glass ribbon drawn from the float bath and the conveying speed of the glass ribbon by the lift-out roll, The problem of wrinkles coming into contact with the lift-out roll was likely to occur.

When the rotation speed of the lift-out roll is reduced with respect to the moving speed of the glass ribbon drawn out from the float bath, the glass ribbon may be deformed near the exit of the float bath.

If a crack in the width direction occurs in the process of pulling the glass ribbon to the height of the lift-out roll near the exit of the float bath, the glass ribbon is cut and the glass ribbon cannot be pulled out continuously. The problem occurs.

These phenomena are likely to occur when a glass plate is thinly formed.

Therefore, an object of the present invention is to provide a glass plate manufacturing apparatus and a glass plate manufacturing method that solve the above-described problems.

In order to solve the above problems, the present invention has the following means.

According to one embodiment, the molten glass is supplied from the inlet of the float bath onto the molten metal in the float bath, and in the float bath forming region, the glass ribbon is spread in the width direction by a support roll to have a predetermined thickness. In a glass plate manufacturing apparatus to be molded into
A glass ribbon delivery means having a drive roll for delivering the glass ribbon in the downstream direction in a slow cooling region between the molding region and the float bath outlet;
The glass ribbon feeding means provides the apparatus for manufacturing a glass plate, wherein the driving roll contacts the both side edges in the width direction of the glass ribbon and drives the both side edges to be sent in the downstream direction. Is done.

According to the present invention, a high-quality glass plate can be obtained stably.

It is the cross-sectional view which looked at an example of schematic structure of the manufacturing apparatus of the glass plate in Embodiment 1 from upper direction. It is the longitudinal cross-sectional view which looked at an example of schematic structure of the manufacturing apparatus of the glass plate in Embodiment 1 from the side. It is a partial longitudinal cross-sectional view which shows the attachment structure of a support roll. It is a partial longitudinal cross-sectional view which shows the attachment structure of a drive roll. It is the figure which looked at the ceramic rotation member of the drive roll from the axial direction. It is a longitudinal cross-sectional view which shows the cross-sectional shape of the ceramic rotation member. It is a figure which expands and shows the attachment structure of a rotating member. It is a figure which shows the modification of a glass ribbon delivery mechanism. It is the figure which looked at the tool steel rotating member of the drive roll from the axial direction. FIG. 10 is a longitudinal sectional view showing a sectional shape of the tool steel rotating member taken along line XX in FIG. 9. It is a figure explaining the convex part of a rotation member. It is a figure for demonstrating the shape of the taper-shaped part of a convex part. It is the cross-sectional view which looked at an example of schematic structure of the manufacturing apparatus of the glass plate in Embodiment 2 from upper direction. It is the longitudinal cross-sectional view which looked at an example of schematic structure of the manufacturing apparatus of the glass plate in Embodiment 2 from the side.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding components are denoted by the same or corresponding reference numerals, and description thereof is omitted.

[Embodiment 1]
FIG. 1 is a cross-sectional view of an example of a schematic configuration of a glass plate manufacturing apparatus 10 according to Embodiment 1 as viewed from above. FIG. 2 is a longitudinal sectional view of an example of a schematic configuration of the glass plate manufacturing apparatus 10 according to the first embodiment as viewed from the side.

As shown in FIGS. 1 and 2, a glass plate manufacturing apparatus 10 is an apparatus for manufacturing a glass plate by a float process. After glass glass is introduced into a molten tin bath and formed into a glass ribbon G, the glass ribbon is manufactured. It is configured to perform slow cooling that gradually lowers the temperature of G.

A melting furnace for generating molten glass is provided on the upstream side of the glass plate manufacturing apparatus 10.

The glass plate manufacturing apparatus 10 has a float bath 20. The float bath 20 is connected to the bathtub 22 that houses the molten metal (for example, molten tin) S, the side wall 24 that is installed along the outer peripheral upper edge of the bathtub 22, and the ceiling 26 that covers the upper side of the bathtub 22. Etc. The ceiling 26 is provided with a gas supply path 30 for supplying a reducing gas in a space 28 formed between the bathtub 22 and the ceiling 26. Further, a heater 32 as a heating source is inserted into the gas supply path 30, and a heat generating portion 32 a of the heater 32 is disposed above the molten metal S and the glass ribbon G.

The forming method using the manufacturing apparatus 10 is a method for forming a ribbon glass ribbon G by causing molten glass introduced onto the molten metal S from the inlet of the float bath 20 to flow in a predetermined direction. The glass ribbon G is cooled in the process of flowing in the downstream direction (X direction in FIGS. 1 and 2), then pulled up from the molten metal S by a lift-out roll, gradually cooled in a slow cooling furnace, and carried out of the slow cooling furnace. After that, it is cut into a predetermined size and shape by a cutting machine to form a glass plate as a product.

The space 28 in the float bath 20 is filled with a reducing gas supplied from the gas supply path 30 in order to prevent the molten metal S from being oxidized. The reducing gas contains, for example, 1 to 15% by volume of hydrogen gas and 85 to 99% by volume of nitrogen gas. The space 28 in the float bath 20 is set to a pressure higher than the atmospheric pressure in order to prevent air from entering through the gaps between the side walls 24 and the like.

In order to adjust the temperature distribution in the float bath 20, a plurality of heaters 32 are provided, for example, at intervals in the flow direction (X direction) and the width direction (Y direction) of the glass ribbon G, and arranged in a lattice pattern. Yes. The output of the heater 32 is controlled so that the temperature of the glass ribbon G becomes higher toward the upstream side in the flow direction (X direction) of the glass ribbon G. The output of the heater 32 is controlled so that the thickness of the glass ribbon G is uniform in the width direction (Y direction).

The interior of the float bath 20 is a predetermined region by spreading a supply region L1 which is a low-viscosity region supplied as described above and a glass ribbon G flowing on the molten metal S to the left and right sides (width direction) downstream thereof. A molding region L2 to be molded to a thickness, and a slow cooling region L3 for gradually cooling the glass ribbon G between the molding region L2 and the outlet 29 of the float bath 20 are provided. A plurality of heaters 32 are arranged on the ceiling 26 in each of the regions L1 to L3. The amount of heating by each heater 32 is controlled in each region, and the viscosity of the glass ribbon G is controlled by adjusting the temperature of the glass ribbon G passing through each region L1 to L3. Further, the slow cooling region L3 is preferably a region having a temperature lower than the softening point of the glass ribbon G.

The viscosity of the molten glass supplied to the supply region L1 is, for example, 10 ⁴ dPa · s.

In the forming region L2, the viscosity of the glass ribbon G is, for example, 10 ^4.5 to 10 ^7.5 dPa · s.

In the forming region L2, in order to prevent the glass ribbon G in the float bath 20 from shrinking in the width direction, a plurality of support rolls 40 that suppress the shrinkage in the width direction of the glass ribbon G are provided.

FIG. 3 is a partial longitudinal sectional view showing the mounting structure of the support roll. As shown in FIG. 3, the support roll 40 is mainly composed of a rotating member 50, a connecting member 60, and a shaft member 65. The shaft member 65 has a distal end penetrating the side wall 24 of the bathtub 22 and inserted into the float bath 20, and a proximal end connected to the driving device 34 disposed outside the side wall 24. The driving device 34 includes a driving motor and a speed reduction mechanism, and rotates the rotating member 50 in the traveling direction of the glass ribbon G. The rotating member 50 applies tension to the end in the width direction of the glass ribbon G so that the convex portion on the outer periphery bites into the upper surface of the glass ribbon G and the glass ribbon G does not contract in the width direction.

The temperature of the glass ribbon G in the slow cooling region L3 is adjusted to, for example, 736 ° C. or less in the case of soda lime (soda lime glass), and to 937 ° C. or less in the case of non-alkali glass, for example. The viscosity of the glass ribbon G in the slow cooling region L3 by the temperature control of the heater control is adjusted to, for example, more than 10 ^7.65 dPa · s. The viscosity of the glass ribbon G in the slow cooling region L3 is harder than when passing through the forming region L2. Driving rolls 71A to 71C of a glass ribbon delivery mechanism 70, which will be described later, are configured to send the glass ribbon G in the downstream direction (X direction).

The temperature of the glass ribbon G in the slow cooling region L3 is lower than the temperature of the region where the glass ribbon width is not reduced, specifically, the glass softening point (the temperature at which the glass viscosity becomes 10 ^7.65 dPa · s). It is preferable. The viscosity of the glass ribbon in the slow cooling region L3 is preferably more than 10 ^7.65 dPa · s, more preferably 10 ^8.3 dPa · s or more, and further preferably 10 ^9.3 dPa · s or more.

A glass ribbon delivery mechanism (glass ribbon delivery means) 70 for delivering the glass ribbon G in the downstream direction (X direction) is disposed in the slow cooling region L3. The glass ribbon delivery mechanism 70 includes a plurality of drive rolls 71A to 71C for driving the glass ribbon G in the downstream direction so as to send out the glass ribbon G at a predetermined moving speed, and a drive device 78.

[Glass ribbon delivery mechanism 70, dross box 80, slow cooling furnace 90]
FIG. 4 is a partial longitudinal sectional view showing a drive roll mounting structure. As shown in FIG. 4, the glass ribbon feeding mechanism 70 has a plurality of driving rolls 71A to 71C and a driving device 78. The drive rolls 71A to 71C are configured by a ceramic or metal rotating member 120, a connecting member 74, and a shaft member 76. Examples of the metal include carbon steel and stainless steel.

The drive device 78 of the glass ribbon delivery mechanism 70 has a drive motor that drives the shaft member 76 to rotate. The drive device 78 includes a drive motor and a speed reduction mechanism, and is controlled by the control device 100 at a rotational speed corresponding to the moving speed of the glass ribbon G, and is rotated via the shaft member 76 and the connecting member 74 of the drive rolls 71A to 71C. The rotational driving force of the member 120 is transmitted to the glass ribbon G. Thereby, the glass ribbon G is sent out to the float bath outlet at a predetermined moving speed.

As shown in FIGS. 1 and 2, a dross box 80 and a slow cooling furnace 90 are provided downstream from the outlet 29 of the float bath 20. The dross box 80 is provided with a plurality of lift-out rolls 82A to 82C for lifting and conveying the glass ribbon G flowing out from the outlet 29 of the float bath 20. The dross box 80 has a drive device 84 that rotationally drives the lift-out rolls 82A to 82C. The drive device 84 includes a drive motor, a speed reduction mechanism, and the like, and rotationally drives each of the lift-out rolls 82A to 82C at a predetermined rotational speed by a control signal output from the control device 100.

The control device 100 drives and controls the drive device 78 so that the conveyance speed of the glass ribbon G by the drive rolls 71A to 71C is the same as the conveyance speed of the glass ribbon G by the lift-out rolls 82A to 82C. Therefore, there is no relative speed difference between the moving speed of the glass ribbon G flowing out from the float bath 20 and the conveying speed of the glass ribbon G by the lift-out rolls 82A to 82C. As a result, the surface of the glass ribbon G that comes into contact with the lift-out rolls 82A to 82C and the transport rolls 92A to 92N of the slow cooling furnace 90 is not wrinkled, and the glass ribbon G is deformed in a wave shape or cut due to generation of cracks in the glass ribbon G. Can be prevented.

Of the plurality of lift-out rolls 82A to 82C, at least the first lift-out roll 82A disposed in the vicinity of the outlet 29 of the float bath 20 may be a free rotating roll.

The slow cooling furnace 90 includes a plurality of transport rolls 92A to 92N and a driving device 94 that rotationally drives the transport rolls 92A to 92N. The drive device 94 includes a drive motor, a speed reduction mechanism, and the like, and rotationally drives the transport rolls 92A to 92N at a predetermined number of rotations according to a control signal output from the control device 100. Although the slow cooling furnace 90 extends downstream, only the transport rolls 92A and 92B are shown in FIGS. 1 and 2, and the other transport rolls are omitted for convenience.

[Rotating member 120]
FIG. 5 is a front view showing the rotating member 120 of the drive rolls 71A to 71C. 6A to 6C are examples of cross-sectional views taken along line VI-VI in FIG. FIG. 7 is an enlarged view showing the mounting structure of the rotating member 120.

As shown in FIG. 6A, for example, the rotating member 120 shown in FIG. 5 has a curved shape with a sectional shape that protrudes radially outward over the entire circumference. The outer peripheral surface 122 of the rotating member 120 has a central portion in the axial direction that protrudes radially outward from both ends in the axial direction. The rotating member 120 does not have gear-like irregularities on the outer peripheral surface 122. Even if there are no gear-like irregularities, the rotating member 120 is made of ceramics, so that a frictional force is generated on the surface of the glass ribbon G.

A plurality of protrusions having a height of 0.1 to 10 mm may be provided on the outer peripheral surface 122 of the rotating member 120, or a plurality of grooves having a depth of 0.1 to 10 mm may be provided on the outer peripheral surface 122 of the rotating member 120. Further, both the protrusion and the groove may be provided on the outer peripheral surface 122 of the rotating member 120. The height of the protrusion and the depth of the groove are measured with reference to the outer peripheral surface 122 of the rotating member 120. The height of the protrusion and the depth of the groove are smaller than the radius r shown in FIG. 6A, the curvature radius Ra shown in FIG. 6B, and Rb and Rc shown in FIG. Thus, by providing small protrusions and grooves on the outer peripheral surface 122, a frictional force is generated on the surface of the glass ribbon G.

Rotating member 120 is neither made of ceramic nor metal, so that no coolant flows inside thereof, so that glass ribbon G is not cooled strongly in the vicinity of rotating member 120 and is difficult to slide with respect to glass ribbon G.

For example, as shown in FIG. 6B, the convex curved radius of curvature Ra is preferably R1 to R100 mm, more preferably R3 to R50 mm, and more preferably R5 to R30 mm in consideration of the grip force with the glass ribbon G. Is more preferable, and R10 to R20 mm is particularly preferable. Further, in the convex curved shape, for example, as shown in FIG. 6C, the curvature radius Rb of the central portion in the axial direction and the curvature radius Rc of both end portions in the axial direction may be a composite R. At this time, the radii of curvature Rb and Rc are preferably R1 to R100 mm, more preferably R3 to R50 mm, still more preferably R5 to R30 mm, and particularly preferably R10 to R20 mm. Further, the convex curved shape may have a flat portion in part, but it is preferable not to have the flat portion because the grip force with the glass ribbon G is stable.

In consideration of the grip force with the glass ribbon G, the radial width d of the rotating member 120 in the convex curved shape shown in FIG. 6B is preferably 0.5 mm or more, more preferably 1 mm or more, and 2 mm or more. Is more preferable. Similarly, the radial width d of the rotating member 120 in the convex curved shape is preferably 5 mm or less, and more preferably 4 mm or less.

The radius r of the rotating member 120 shown in FIG. 6B is preferably 100 mm or more, more preferably 150 mm or more, and more preferably 180 mm or more in consideration of prevention of contact between the connecting member 74 and the glass ribbon G and the horizontality of the shaft member 76. Is more preferable, and 350 mm or less is preferable, 300 mm or less is more preferable, and 270 mm or less is more preferable in consideration of position adjustment between the rotating member 120 and the glass ribbon G and fine adjustment of the rotation speed of the rotating member 120.

The thickness w of the rotating member 120 is preferably 5 mm or more, more preferably 10 mm or more, further preferably 15 mm or more, and particularly preferably 30 mm or more, considering the gripping force with the glass ribbon G, and the flatness of the glass ribbon G is improved. In view of preventing unnecessary increase in grip width, it is preferably 120 mm or less, more preferably 100 mm or less, still more preferably 80 mm or less, still more preferably 60 mm or less, and particularly preferably 40 mm or less.

Thus, as shown in FIGS. 5A to 5C, the outer peripheral surface 122 of the rotating member 120 is a curved shape whose cross-sectional shape is convex outward in the radial direction over the entire circumference. Therefore, it is difficult to break and the molding and processing costs are reduced. 5A to 5C are preferable because the glass ribbon G can be stably formed into a sheet glass. However, small irregularities can be provided on the outer peripheral surface 122 of the rotating member 120. When this small unevenness is provided on the outer peripheral surface 122, a frictional force against the surface of the glass ribbon G can be obtained more.

The rotating member 120 shown in FIG. 4 does not have a coolant channel inside, and is formed of ceramics. Ceramics has a high temperature strength higher than that of conventional metals such as steel and heat-resistant alloys, so that the conventionally required refrigerant flow path is not required. Therefore, since the refrigerant does not flow through the rotating member 120, the glass ribbon G is not easily cooled in the vicinity of the rotating member 120. As a result, the temperature of the glass ribbon G, and hence the thickness of the glass ribbon G, is stabilized, so that the flatness of the glass plate as a product is improved. Further, in the vicinity of the rotating member 120, the glass ribbon G is hard to be strongly cooled and hard to be hardened. Therefore, the glass ribbon G of the rotating member 120 is also used in the slow cooling region L3 in which the glass temperature is lowered and the glass surface is hardened. Gripping performance is improved. This effect is remarkable on the downstream side in the flow direction where the temperature of the glass ribbon G is lowered.

The ceramics are not particularly limited, for example, silicon carbide (SiC) quality ceramics, silicon nitride _(Si 3 _{N 4)} such quality ceramics are used. Silicon carbide and silicon nitride have high resistance to the splash of the molten metal S and the vapor of the molten metal S, and are excellent in high-temperature strength and creep characteristics.

The type of ceramic is selected according to the type of product glass plate (that is, a glass ribbon G that has been slowly cooled and cooled). For example, when the glass plate is alkali-free glass, silicon nitride ceramics excellent in thermal shock resistance are suitable. In the case of non-alkali glass, the temperature in the float bath 20 tends to be high, so that the higher the thermal shock resistance, the higher the degree of freedom of operation. Furthermore, the higher the temperature, the more likely the reactivity with the glass ribbon G and the molten tin S becomes a problem, but the silicon nitride ceramic tends to have a low reactivity. When the glass plate is soda lime glass, silicon carbide ceramics or alumina ceramics can be used in addition to silicon nitride ceramics.

The composition of the glass plate used in the present embodiment is, for example, expressed in terms of mass percentage on the basis of oxide, 50 to 75% for SiO ₂ , 0.1 to 24% for Al ₂ O ₃ , and 0 to 0 for B ₂ O _3. 12%, MgO 0-10%, CaO 0-14.5%, SrO 0-24%, BaO 0-13.5%, Na ₂ O 0-20%, K ₂ O 0-0 20%, ZrO ₂ 0 to 5%, MgO + CaO + SrO + BaO 5 to 29.5%, Na ₂ O + K ₂ O 0 to 20%.

The alkali-free glass is a glass that does not substantially contain an alkali metal oxide (Na ₂ O, K ₂ O, Li ₂ O). The total content (Na ₂ O + K ₂ O + Li ₂ O) of the alkali metal oxide content in the alkali-free glass may be, for example, 0.1% or less.

The alkali-free glass is, for example, expressed in terms of mass percentage based on oxide, SiO ₂ : 50 to 70%, preferably 50 to 66%, Al ₂ O ₃ : 10.5 to 24%, B ₂ O ₃ : 0 to 12%, MgO: 0 to 10%, preferably 0 to 8%, CaO: 0 to 14.5%, SrO: 0 to 24%, BaO: 0 to 13.5%, ZrO ₂ : 0 to 5% MgO + CaO + SrO + BaO: 8 to 29.5%, preferably 9 to 29.5%.

The alkali-free glass has a high strain point, and when considering the solubility, it is preferably expressed in terms of mass percentage based on oxide, SiO ₂ : 58 to 66%, Al ₂ O ₃ : 15 to 22%, B ₂ O ₃ : 5 to 12%, MgO: 0 to 8%, CaO: 0 to 9%, SrO: 3 to 12.5%, BaO: 0 to 2%, MgO + CaO + SrO + BaO: 9 to 18% is there.

When considering the high strain point, the alkali-free glass is preferably expressed in terms of mass percentage based on oxide, SiO ₂ : 54 to 73%, Al ₂ O ₃ : 10.5 to 22.5%, B ₂ O ₃ : 0 to 5.5%, MgO: 0 to 10%, CaO: 0 to 9%, SrO: 0 to 16%, BaO: 0 to 2.5%, MgO + CaO + SrO + BaO: 8 to 26% is there.

When the type of glass plate is non-alkali glass, at least a portion of the rotating member 120 that contacts the glass ribbon G may be silicon nitride ceramics, and the entire rotating member 120 is not silicon nitride ceramics. Also good. For example, a silicon nitride ceramic layer may be formed on a base material made of metal, carbon or other ceramics by film formation, bonding or fitting. Thus, different types of ceramics may be used for each part of the rotating member 120. In the present embodiment, the entire rotating member 120 is formed of silicon nitride ceramics.

The silicon nitride ceramics may be a sintered body obtained by sintering a molded body made of a mixed powder containing silicon nitride powder and sintering aid powder. As the sintering method, there are an atmospheric pressure sintering method, a pressure sintering method (including hot press sintering, gas pressure sintering) and the like. As the sintering aid, for example, at least one selected from alumina (Al ₂ O ₃ ), magnesia (MgO), titania (TiO ₂ ), zirconia (ZrO ₂ ), and yttria (Y ₂ O ₃ ) is used. It is done.

The silicon nitride ceramic has an aluminum (Al) content of 0.1% by mass or less, preferably less than 1% by mass, and a magnesium (Mg) content of 0.7% by mass or less, preferably 0.7% by mass. The titanium (Ti) content is 0.9 mass% or less, preferably less than 0.9 mass%. When the Al content, the Mg content, and the Ti content are in the above ranges, it is difficult to react with the glass ribbon G, and the glass ribbon G is difficult to adhere, so that good durability is obtained. In addition, 0 mass% may be sufficient as Al content, Mg content, and Ti content, respectively.

The silicon nitride ceramic has a zirconium (Zr) content of 3.5% by mass or less, preferably less than 3.5% by mass, and a yttrium (Y) content of 0.5% by mass or more, preferably 0.5%. It is preferable to be more than 10% by mass, more preferably less than 10% by mass. Zr and Y are components that are less likely to interdiffuse with the glass ribbon G as compared with Al, Mg, and Ti, and thus may be contained in the above range. By containing in the above range, sintering of the silicon nitride powder can be promoted. Zr is an optional component, and the Zr content may be 0% by mass.

The silicon nitride ceramic of the present embodiment is a sintered body obtained by a normal pressure sintering method or a pressure sintering method, but may be a sintered body obtained by a reactive sintering method. . The reaction sintering method is a method in which a molded body formed of metal silicon (Si) powder is heated in a nitrogen atmosphere. Since the reaction sintering method does not use a sintering aid, a high-purity sintered body can be obtained, and the durability of the sintered body with respect to the glass ribbon G can be improved.

A circular hole 124 is formed through the center of the rotating member 120. The rod portion 74c is inserted through the circular hole 124. The inner diameter of the circular hole 124 is larger than the outer diameter of the rod portion 74c.

As shown in FIG. 7, the rotating member 120 has a pair of insertion holes 126 formed therethrough. The

shaft portions

75 and 75 are inserted through the respective insertion holes 126. The inner diameter of each insertion hole is larger than the outer diameter of the

corresponding shaft portions

75 and 75.

[Shaft member 76]
As shown in FIG. 7, the shaft member 76 is made of stainless steel (steel material represented by SUS in Japanese Industrial Standards (JIS)) or carbon steel (steel material represented by SC in Japanese Industrial Standards (JIS)). It may be made of a metal material. A heat insulating material or the like may be wound around the outer periphery of the shaft member 76.

As shown in FIG. 4, the shaft member 76 penetrates the side wall 24, and is connected to a drive device 78 configured by a motor, a speed reducer, and the like outside the float bath 20. When the driving device 78 is operated, the shaft member 76, the connecting member 74, and the rotating member 120 are integrally rotated around the central axis of the shaft member 76.

The connecting member 74 is a member that connects the shaft member 76 and the rotating member 120. The connecting member 74 is, for example, cylindrical, and the outer diameter and inner diameter of the end of the connecting member 74 on the shaft member 76 side are the same as the outer diameter and inner diameter of the outer tube of the shaft member 76, respectively. The connecting member 74 is abutted against the outer tube of the shaft member 76 and is connected coaxially, for example, by welding. The connecting member 74 is preferably made of a material that can be easily welded to the shaft member 76, and more preferably formed of the same material.

[Connecting member 74]
The connecting member 74 is integrated with the shaft member 76 and may be formed of a metal material such as steel or a heat-resistant alloy. The rotating member 120 is detachably attached to the connecting member 74.

The connecting member 74 includes a shaft portion 74a integrated with the shaft member 76, an annular flange portion 74b projecting radially outward from the tip portion of the shaft portion 74a, and a tip portion of the shaft portion 74a. And a rod portion 74c extending coaxially with the shaft portion 74a.

The shaft portion 74a is abutted against the shaft member 76 and integrated by welding, for example. The flange portion 74b protrudes outward in the radial direction of the shaft portion 74a from the tip end portion (the end portion opposite to the shaft member 76) of the shaft portion 74a.

The rod portion 74c extends coaxially with the shaft portion 74a from the tip portion of the shaft portion 74a. The rod portion 74c penetrates the rotating member 120 and has a male screw portion at the tip. The axial movement of the rotating member 120 is limited by the nut 73 screwed to the male screw portion and the flange portion 74b. By removing the nut 73 from the male screw portion, the rotating member 120 can be removed.

The connecting member 74 is fixed to the surface on the distal end side of the flange portion 74b and has shaft portions 67 and 68 parallel to the central axis of the rod portion 74c. The connecting member 74 and the rotating member 120 can be integrally rotated by the shaft portion 75 and the rod portion 74c.

As shown in FIG. 7, each of the shaft portions 75 penetrates the rotating member 120 and has a male screw portion at the tip portion. The axial movement of the rotating member 120 is limited by the nut 77 screwed to the male screw portion and the flange portion 74b. By removing the nut 77 from the male screw portion, the rotating member 120 can be removed.

[Modification of glass ribbon feeding mechanism]
FIG. 8 is a view showing a modification of the glass ribbon delivery mechanism. As shown in FIG. 8, a modified example of the glass ribbon feeding mechanism 70A includes a plurality of driving rolls 71A to 71C and a driving device 78. The drive rolls 71A to 71C are constituted by a rotating member 72 made of tool steel, a connecting member 74A, and a shaft member 76A.

[Shaft member 76A]
The shaft member 76A has a refrigerant flow path inside, and is cooled by the refrigerant flowing through the refrigerant flow path, and is made of stainless steel (steel material represented by SUS in Japanese Industrial Standards (JIS)) or carbon steel (Japanese Industrial Standards). It may be formed of a metal material such as (a steel material represented by SC in (JIS)). A heat insulating material or the like may be wound around the outer periphery of the shaft member 76A.

The shaft member 76A is, for example, a double pipe, and includes an inner pipe and an outer pipe. A refrigerant flow path is constituted by the inner space of the inner tube and the space formed between the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube.

As the refrigerant, a liquid such as water or a gas such as air is used. The refrigerant passes through the inner space of the inner tube, passes through the space formed between the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube, after being supplied to the inner space of the connecting member 74A and the rotating member 72, It is discharged outside. The refrigerant discharged to the outside may be cooled by a cooler and returned to the inner space of the inner pipe again. Note that the flow direction of the refrigerant may be in the opposite direction.

As shown in FIG. 8, the shaft member 76 </ b> A penetrates the side wall 24, and is connected to the drive device 34 constituted by a motor, a speed reducer, and the like outside the float bath 20. When the driving device 34 is operated, the shaft member 76A, the connecting member 74, and the rotating member 72 are integrally rotated around the central axis of the shaft member 76A.

The connecting member 74 </ b> A is a member that connects the shaft member 76 </ b> A and the rotating member 72. The connecting member 74A has an inner space communicating with the refrigerant flow path of the shaft member 76A. The connecting member 74A has, for example, a cylindrical shape, and the outer diameter and inner diameter of the end of the connecting member 74A on the shaft member 76A side are the same as the outer diameter and inner diameter of the outer tube of the shaft member 76A, respectively. The connecting member 74A is abutted against the outer tube of the shaft member 76A, and is connected coaxially by welding, for example. The connecting member 74A is preferably made of a material that can be easily welded to the shaft member 76A, and more preferably formed of the same material.

[Rotating member 72 of driving roll]
FIG. 9 is a front view showing a rotating member of a modification. FIG. 10 is a partially enlarged view of a cross section taken along line XX of FIG. 11A and 11B are diagrams for explaining the convex portion of the rotating member 72. FIG. 12A shows a cross section of the tapered portion of the convex portion, and FIG. 12B shows the pitch and height of the convex portion.

As shown in FIG. 9, the rotating member 72 has a disk shape, and the central axis of the rotating member 72 and the central axis of the shaft member 76 are on the same straight line. The rotating member 72 is in contact with the surface of the glass ribbon G (the upper surface in the present embodiment) at the outer periphery. As the rotating member 72 rotates, the glass ribbon G is sent out in a predetermined direction (X direction).

For example, as shown in FIG. 9, the rotating member 72 integrally includes a disk-shaped main body 72 a and a plurality of convex portions 72 b provided along the outer periphery of the main body 72 a.

As shown in FIGS. 10 and 11, the rotating member 72 has an inner space 72 c as a refrigerant flow path. The inner space 72c communicates with the inner space of the connecting member 74A through an opening formed on the back side of the rotating member 72.

The plurality of convex portions 72b are provided at equal intervals in the circumferential direction. The convex portion 72b makes it difficult for the rotating member 72 to slip on both side edges of the glass ribbon G even in the slow cooling region L3 where the glass temperature is lowered and the glass surface is hardened. Further, as shown in FIG. 10, the gear-shaped convex portions 72b are formed in two rows on the outer periphery of the main body portion 72a, but may be formed in three or more rows, or may be formed in only one row. In consideration of preventing the cooling of the glass ribbon G, the convex portions 72b are preferably formed in one or two rows.

Each convex portion 72b may be tapered (for example, a quadrangular pyramid shape) so as to easily bite into the glass ribbon G.

The angle A or B (see FIG. 12A) of the tapered portion 72b with respect to the surface perpendicular to the shaft member 76A is preferably 45 ° or less, and preferably 30 ° or less in view of the grip force with respect to the glass ribbon G. More preferably, it is more preferably 25 ° or less. In consideration of the strength of the tapered portion, the angle A or B is preferably 15 ° or more.

The width C (see FIG. 12A) of the tip of the tapered portion of the convex portion 72b is preferably 2 mm or less, more preferably 1 mm or less, and more preferably 0.5 mm or less in consideration of the grip force with respect to the glass ribbon G. preferable. The tip portion does not necessarily have to be linear, and may have a curved shape or a composite shape.

The pitch D of the convex portions 72b (see FIG. 12 (b)) is preferably 6.5 mm or less, more preferably 5.5 mm or less in consideration of the grip force with respect to the glass ribbon G. In consideration of the strength and workability of the tapered portion, the pitch D is preferably 1.5 mm or more, and more preferably 2.5 mm or more.

The height E of the convex portion 72b (see FIG. 12B) is preferably 4 mm or more, more preferably 5 mm or more in consideration of the grip force with respect to the glass ribbon G. In consideration of the strength and workability of the tapered portion, the height E is preferably 8 mm or less, and more preferably 7 mm or less.

The radius of the rotating member 72 is preferably 100 mm or more, more preferably 150 mm or more, further preferably 180 mm or more, in consideration of prevention of contact between the connecting member 74 and the glass ribbon G and the horizontality of the shaft member 76. Considering position adjustment with the glass ribbon G and fine adjustment of the rotation speed of the rotating member 72, 350 mm or less is preferable, 300 mm or less is more preferable, and 270 mm or less is more preferable.

At least the projection 72b of the rotating member 72 is formed of tool steel, preferably hot die steel. In the present embodiment, the main body 72a is also made of tool steel.

Here, “hot die steel” means “hot mold” alloy tool steel among “SKD” described in JIS G4404.

The tool steel is not particularly limited, and for example, steel materials represented by SKS, SKD, SKT, and SKH in Japanese Industrial Standard (JIS) can be used. Examples of tool steel include SKS4, SKS41, SKS42, SKS43, SKS44, SKS1, SKS11, SKS2, SK21, SKS5, SKS51, SKS7, SKS8, SKS3, SKS31, SKS93, SKD1, SKD11, SKD11, SKD11, SKD11, SKD11 SKD6, SKD61, SKT1, SKT2, SKT3, SKT4, SKT5, SKT6, SKH2, SKH3, SKH4A, SKH4B, SKH40, SKH5, SKH51, SKH52, SKH53, HSK58, S The steel developed by each company improved from these grades can be used. Such a developed steel is mainly composed of Fe, and preferably has a C content of 0.3 to 2.5% by mass, a Si content of 0 to 1.1% by mass, and a Mn content of 0 to 1.1 mass%, Ni content 0-2.0 mass%, Cr content 0-13.5 mass%, Mo content 0-5.0 mass%, V content The content is 0 to 4.0 mass%, the W content is 0 to 10.0 mass%, and the Co content is 0 to 10.0 mass%. The hot die steel is not particularly limited, and SKD61 and improved steel materials of various companies can be used. Such hot die steel has Fe as a main component, preferably C content of 0.3 to 0.5% by mass, Si content of 0.3 to 1.20% by mass, Mn content The amount is 0.4 to 0.9% by mass, the Ni content is 0 to 1.8% by mass, the Cr content is 1.3 to 5.50% by mass, and the Mo content is 0.4 to 2%. 0.7% by mass and the V content is 0.2 to 1.7% by mass. From the viewpoint of workability and cost, the hot die steel is preferably SKD61. SKD61 is mainly composed of Fe, and has a C content of 0.35 to 0.42 mass% and a Si content of 0.80 to 1.20, as defined in Japanese Industrial Standards (JIS). Mass%, Mn content 0.25 to 0.50 mass%, P content 0 to 0.030 mass%, S content 0 to 0.020 mass%, Cr content 4 .80 to 5.50 mass%, steel content of Mo 1.00 to 1.50 mass%, V content 0.80 to 1.15 mass%, inevitably contained impurities May further be included. SKD61 may be expressed as X40CrMoV5-1 in the international standard (ISO 4957: 1999).

Since tool steel has high temperature strength compared to conventional materials such as SUS and SC, the deformation of the convex portion 72b that bites into the glass ribbon G can be suppressed, and the durability of the rotating member 72 can be improved.

Since tool steel has high temperature strength compared to conventional materials such as SUS and SC, the convex portion 72b can be sharpened so that the convex portion 72b can easily bite into the glass ribbon G. This effect is remarkable because the glass ribbon G cools and becomes harder toward the downstream side in the float bath 20, and the drive rolls 71A to 71C can be used in a temperature range that could not be used conventionally.

As shown in FIG. 11, the rotating member 72 may have a protective film 72d having excellent corrosion resistance on at least a part of the outer surface. In particular, it is preferable to have a protective film 72d containing chromium nitride or metallic chromium. Since chromium nitride and metallic chromium have higher corrosion resistance against the splash of molten tin S and steam than hot die steel, the tin resistance of the rotating member 72 can be improved.

The protective film 72d covers the outer surface of the convex portion 72b and covers a part of the outer surface of the main body portion 72a.

Examples of the method for forming the protective film 72d include a plating method, a vapor deposition method, a sputtering method, a CVD method, an ion coating method, and a thermal spraying method, which are appropriately selected according to the shape of the convex portion 72b. For example, when sharpening the convex part 72b, dry coating methods, such as a vapor deposition method, sputtering method, and an ion coating method, are preferable.

[Embodiment 2]
FIG. 13: is the cross-sectional view which looked at an example of schematic structure of 10 A of glass plate manufacturing apparatuses in Embodiment 2 from upper direction. FIG. 14 is a longitudinal sectional view of an example of a schematic configuration of a glass plate manufacturing apparatus 10 </ b> A according to Embodiment 2 as viewed from the side. In FIG. 13 and FIG. 14, the same parts as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIGS. 13 and 14, the glass plate manufacturing apparatus 10A according to the second embodiment has a glass ribbon holding mechanism (glass glass) above the lift-out rolls 82A to 82C arranged downstream of the outlet 29 of the float bath 20. Ribbon presser means) 170 presser rolls 171A to 171C, and a driving device 178 that rotationally drives each presser roll 171A to 171C. The drive device 178 includes a drive motor, a speed reduction mechanism, and the like, and is controlled by the control device 100 at a rotational speed corresponding to the moving speed of the glass ribbon G.

The press rolls 171A to 171C of the glass ribbon press mechanism 170 are arranged above the lift out rolls 82A to 82C arranged downstream of the float bath outlet.

The presser rolls 171A to 171C are configured by a ceramic or metal rotating member 120, a connecting member 74, and a shaft member 76, similarly to the drive rolls 71A to 71C described above. The presser rolls 171A to 171C are in contact with both side edges in the width direction of the glass ribbon G, and press the lift-out rolls 82A to 82C so as to feed the both side edges of the glass ribbon G in the downstream direction. The glass ribbon G sent out from the outlet 29 of the float bath 20 by the rotation of the drive rolls 71A to 71C is further sent downstream by the rotation of the press rolls 171A to 171C and the lift-out rolls 82A to 82C.

As described above, the rotating member 120 of the presser rolls 171A to 171C has the outer peripheral surface 122 made of ceramics or metal, for example, as shown in FIG. The curved shape. In addition, since the refrigerant does not flow inside the ceramic and metal rotating member 120, the glass ribbon G is not cooled strongly in the vicinity of the rotating member 120, and the glass ribbon G is difficult to slip.

The shaft member 76 of the presser rolls 171A to 171C extends to the outside of the dross box 80 and is connected to a driving device 178 disposed outside the dross box 80. The drive device 178 is rotationally controlled by the control signal output from the control device 100 so as to have the same conveyance speed as the lift-out rolls 82A to 82C.

Instead of the ceramic or metal rotating member 120, a tool steel rotating member 72 may be used. For example, as shown in FIGS. 8 and 9, the rotating member 72 has a rotating member 72 having gear-like irregularities 72 b on the outer periphery, and is difficult to slip on the surface of the glass ribbon G. Since the presser rolls 171A to 171C are provided outside the float bath 20, the above-described cooler and refrigerant passages need not be provided.

It should be noted that any one or any two of the presser rolls 171A to 171C may be provided.

The number of presser rolls 171A to 171C may be provided in accordance with the number of lift-out rolls 82A to 82C, or a number smaller than the number of lift-out rolls 82A to 82C may be provided.

At least the first presser roll 171A and the lift-out roll 82A close to the outlet 29 of the float bath 20 may be free-rotating rolls.

The preferred embodiments and examples of the present invention have been described in detail above. However, the present invention is not limited to the specific embodiments and examples described above, and is based on the gist of the present invention described in the claims. Various modifications and changes can be made within the range.

This international application claims priority based on Japanese Patent Application No. 2013-104537 filed on May 16, 2013, the entire contents of which are incorporated herein by reference.

10, 10A Glass plate manufacturing apparatus 20 Float bath 22 Bathtub 24 Side wall 26 Ceiling 28 Space 29 Exit 30 Gas supply path 32 Heater

32a Heating part

34, 78, 84, 94, 178 Drive device 40

Support roll

50, 72, 120

Rotation Members

60, 74,

74A Connecting members

65, 76, 76A Shaft members 67, 68, 75

Shaft portions

70, 70A Glass ribbon delivery mechanisms 71A-71C Drive roll 72a Main body portion 72b Convex portion 72c Inner space 72d

Protective films

73, 77 Nut

74a Shaft portion

74b Flange portion

74c Rod portion 80 Dross boxes 82A to 82C Lift out roll 90 Slow cooling furnace
92A to 92N Transport roll 100 Controller 122 Outer peripheral surface 124 Circular hole 126 Insertion hole 170 Glass ribbon presser mechanism 171A to 171C Presser roll G Glass ribbon S Molten metal L1 Supply region L2 Molding region L3 Slow cooling region

Claims

Manufacture of a glass plate in which molten glass is supplied from the inlet of the float bath onto the molten metal in the float bath, and in the float bath forming region, the glass ribbon is spread in the width direction by a support roll and formed into a predetermined thickness. In the device
A glass ribbon delivery means having a drive roll for delivering the glass ribbon in the downstream direction in a slow cooling region between the molding region and the float bath outlet;
The said glass ribbon sending means makes the said drive roll contact the both-sides edge part of the width direction of the said glass ribbon, and drives the said both-sides edge part to send out downstream, The manufacturing apparatus of the glass plate characterized by the above-mentioned.
The glass sheet manufacturing apparatus according to claim 1, wherein the slow cooling region is a region where the temperature of the glass ribbon is lower than the softening point of the glass ribbon.
The said drive roll is a manufacturing apparatus of the glass plate of Claim 1 or 2 which has a rotating member formed with ceramics.
The said drive roll is a manufacturing apparatus of the glass plate of Claim 1 or 2 which has a rotating member formed with the metal.
The apparatus for producing a glass plate according to claim 1 or 2, wherein the drive roll has a rotating member having a plurality of convex portions formed on an outer periphery, and at least the convex portions are formed of tool steel.
The apparatus for producing a glass plate according to any one of claims 1 to 5, wherein the driving roll is driven at the same glass transport speed as a lift-out roll for pulling out the glass ribbon from the float bath.
The glass plate manufacturing apparatus according to claim 6, wherein at least a lift-out roll adjacent to the outlet freely rotates by contact with the glass ribbon.
The glass ribbon pressing means having a pressing roll for feeding the glass ribbon in the downstream direction is provided at a position facing the lift-out roll with the glass ribbon interposed therebetween. Glass plate manufacturing equipment.
Manufacture of a glass plate in which molten glass is supplied from the inlet of the float bath onto the molten metal in the float bath, and in the float bath forming region, the glass ribbon is spread in the width direction by a support roll and formed into a predetermined thickness. In the method
A glass ribbon delivery means having a drive roll for delivering the glass ribbon in the downstream direction is provided in a slow cooling area between the molding area and the float bath outlet, and the glass ribbon delivery means is configured to send the drive roll to the glass ribbon. A method of manufacturing a glass plate, comprising: contacting both side edges in the width direction and driving the both side edges in a downstream direction.
The method for producing a glass plate according to claim 9, further comprising a step of gradually cooling and cutting the glass ribbon fed by the drive roll.