JP7251444B2 - Glass plate manufacturing apparatus and glass plate manufacturing method - Google Patents

Description

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

A manufacturing apparatus for a glass sheet includes a forming furnace and rolls for suppressing shrinkage of a band-shaped glass ribbon in the width direction inside the forming furnace. A plurality of pairs of 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 roll has a disk-shaped rotating member and a rotating shaft that rotates the rotating member.

The rotating member presses the widthwise end of the glass ribbon at its outer periphery and feeds the glass ribbon in the longitudinal direction of the glass ribbon. The glass ribbon is gradually cooled while moving inside the forming furnace. The rotating member is generally made of metal, and has gear-shaped unevenness on its outer periphery that contacts the glass ribbon. Metal has low heat resistance and insufficient high-temperature strength (for example, strength at 500° C. or higher), so a coolant channel is formed inside the rotating member. The coolant conveys the heat of the rotating member to the outside and suppresses the temperature rise of the rotating member.

As the glass ribbon in the forming furnace cools as it moves downstream, the glass ribbon hardens as it moves. As a result, the rotating member cannot sufficiently grip the glass ribbon.

Therefore, Patent Document 1 proposes a rotary member made of ceramic. Since ceramics are superior in heat resistance to metals, coolant channels are not formed inside the rotating member. Therefore, it is possible to prevent the glass ribbon from being cooled via the rotating member, and suppress a decrease in the gripping force of the rotating member with respect to the glass ribbon. It should be noted that the rotating member made of ceramic does not need to have gear-shaped irregularities on its outer periphery in order to obtain a gripping force.

WO2013/073352

However, even a rotating member made of ceramic may not be able to obtain a sufficient grip on a hardened glass ribbon.

One aspect of the present disclosure provides a technique that can improve the gripping force of the rotating member on the glass ribbon.

A glass plate manufacturing apparatus according to an aspect of the present disclosure includes:
It has a rotating member made of ceramic, a rotating shaft for rotating the rotating member, and a coolant channel formed inside the rotating shaft, and a width direction of a band-shaped glass ribbon on the outer periphery of the rotating member. A roll that presses the end portion and sends out the glass ribbon in the longitudinal direction of the glass ribbon;
a heating mechanism for heating the outer circumference of the rotating member;
with
The heating mechanism is characterized by including an irradiator that irradiates the outer circumference of the rotating member with a laser beam.

According to one aspect of the present disclosure, it is possible to improve the gripping force of the rotating member on the glass ribbon.

FIG. 1 is a vertical cross-sectional view showing a forming apparatus of a glass plate manufacturing apparatus according to one embodiment. 2 is a cross-sectional plan view showing the lower structure of the molding apparatus of FIG. 1. FIG. 3 is a vertical cross-sectional view showing a portion of the molding apparatus of FIG. 1; FIG. FIG. 4 is a vertical cross-sectional view showing part of a molding device according to a first modified example. FIG. 5 is a vertical sectional view showing part of a molding device according to a second modification. FIG. 6 is a vertical sectional view showing part of a molding device according to a third modified example. FIG. 7A is a perspective view showing an example of a heating wire and electrodes. FIG. 7B is a perspective view showing another example of the heating wire and the electrodes. FIG. 7C is a perspective view showing still another example of the heating wire and the electrodes.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In addition, in each drawing, the same reference numerals are given to the same or corresponding configurations, and explanations thereof may be omitted.

In each drawing, the X-axis direction, Y-axis direction and Z-axis direction are perpendicular to each other, the X-axis direction and Y-axis direction are horizontal directions, and the Z-axis direction is vertical direction. When the glass ribbon forming method is the float method, the X-axis direction is the moving direction of the glass ribbon, and the Y-axis direction is the width direction of the glass ribbon.

In the specification, "-" indicating a numerical range means that the numerical values described before and after it are included as lower and upper limits.

(Glass plate manufacturing apparatus and glass plate manufacturing method according to one embodiment)
A glass plate manufacturing apparatus and a glass plate manufacturing method according to an embodiment will be described with reference to FIGS.

As shown in FIGS. 1 and 2, the glass sheet manufacturing apparatus has a forming apparatus 1 . The forming apparatus 1 forms the molten glass into a strip shape to obtain a glass ribbon G. The forming apparatus 1 obtains the glass ribbon G by, for example, the float method. In the float method, molten glass is continuously supplied above the liquid surface of molten metal M such as molten tin, and the supplied molten glass is moved above the liquid surface of molten metal M from the negative side in the X-axis direction to the positive side in the X-axis direction. Form into a strip while flowing sideways. After the glass ribbon G is taken out from the forming apparatus 1, it is slowly cooled by a slow cooling apparatus and then cut by a processing apparatus. Since the slow cooling device and the processing device are common ones, illustration thereof is omitted. After processing, a glass plate is obtained as a product.

The glass plate is composed of, for example, SiO ₂ : 50% to 75%, Al ₂ O ₃ : 0.1% to 24%, B ₂ O ₃ : 0% to 12%, MgO: 0% to 10%, CaO: 0% to 14.5%, SrO: 0% to 24%, BaO: 0% to 13.5%, Na ₂ O: 0% to 20%, K ₂ O: 0% ZrO ₂ : 0% to 5%, MgO+CaO+SrO+BaO: 5% to 29.5%, Na ₂ O+K ₂ O: 0% to 20%.

The type of glass for the glass plate is selected according to the use of the glass plate. The use of the glass plate is not particularly limited, but is, for example, a flat panel display (FPD) such as a liquid crystal display (LCD) or an organic EL display. When the application of the glass plate is FPD, the type of glass of the glass plate is non-alkali glass. Alkali-free glass is glass that does not substantially contain alkali metal oxides (Na ₂ O, K ₂ O, Li ₂ O, etc.). The alkali-free glass may have a total content of alkali metal oxides of 0.1% by mass or less.

Alkali-free glass is, for example, SiO ₂ : 50% to 70% (preferably 50% to 66%), Al ₂ O ₃ : 10.5% to 24%, B ₂ O, in terms of % by mass based on oxides. ₃ : 0%-12%, MgO: 0%-10% (preferably 0%-8%), CaO: 0%-14.5%, SrO: 0%-24%, BaO: 0%-13. 5%, ZrO ₂ : 0% to 5%, MgO+CaO+SrO+BaO: 8% to 29.5% (preferably 9% to 29.5%).

When the alkali-free glass has both a high strain point and a high solubility, it preferably contains SiO ₂ : 58% to 66%, Al ₂ O ₃ : 15% to 22%, in terms of % by mass based on oxides. 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% ~ Contains 18%.

When it is desired to obtain a particularly high strain point, alkali-free glass preferably contains SiO ₂ : 54% to 73%, Al ₂ O ₃ : 10.5% to 22.5%, in terms of % by mass based on oxides. 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%.

The thickness of the glass plate is selected according to the use of the glass plate. When the application of the glass plate is FPD, the thickness of the glass plate is preferably 0.7 mm or less, more preferably 0.5 mm or less, still more preferably 0.3 mm or less, still more preferably 0.2 mm or less, and particularly preferably 0.1 mm or less.

The forming apparatus 1 includes a forming furnace 2 as shown in FIG. The forming furnace 2 has a bath 20 containing the molten metal M, a ceiling 21 provided above the bath 20 , and a side wall 22 closing a gap between the bath 20 and the ceiling 21 . A gas supply hole 23 is provided in the ceiling 21 . The gas supply hole 23 supplies a reducing gas to the space above the molten metal M to prevent the molten metal M 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 forming apparatus 1 includes a heater 3 that heats the glass ribbon G inside the forming furnace 2 . The heaters 3 are, for example, inserted through the gas supply holes 23 of the ceiling 21 and arranged in a matrix in the X-axis direction and the Y-axis direction above the molten metal M and the glass ribbon G. As shown in FIG. The output of the heater 3 is controlled such that the temperature of the glass ribbon G decreases from the negative side in the X-axis direction to the positive side in the X-axis direction. Moreover, the output of the heater 3 is controlled so that the thickness of the glass ribbon G becomes uniform in the Y-axis direction.

The forming apparatus 1 includes rolls 5 that press the ends of the strip-shaped glass ribbon G in the width direction inside the forming furnace 2 and send out the glass ribbon G in the longitudinal direction of the glass ribbon G. As shown in FIG. The glass ribbon G is gradually cooled and hardened while moving in the X-axis direction. A plurality of pairs of rolls 5 are provided on both sides in the width direction of the glass ribbon G to suppress contraction of the glass ribbon G in the width direction. The thickness of the glass ribbon G can be made thinner than the equilibrium thickness.

As shown in FIG. 2, the roll 5 presses the widthwise end of the glass ribbon G at least in the forming region A1, preferably both in the forming region A1 and the low temperature region. . The molding region A1 is a region where the glass ribbon G has a viscosity of 10 ^4.5 dPa·s to 10 ^7.5 dPa·s. The low-temperature region is a region with a temperature lower than that of the forming region A1, and is a region in which the viscosity of the glass ribbon G is in the range of more than 10 ^7.5 dPa·s to 10 ^7.65 dPa·s. The mixing zone includes all of the downstream region of the forming zone A1 and the low temperature zone, and is a region in which the viscosity of the glass ribbon G is 10 ^6.7 dPa·s to 10 ^7.65 dPa·s. In addition, since the outer periphery of the rotating member 51 of the roll 5 is heated by the heating mechanism 7, which will be described later, the width of the glass ribbon G is reduced in the slow cooling region A2, which is a region in which the viscosity of the glass ribbon G exceeds 10 ^7.65 dPa s. Hold the direction end. These viscosities are measured at the center of the glass ribbon G in the width direction.

For example, the relationship between the viscosity and temperature of alkali-free glass is as follows. A viscosity of 10 ^4.5 dPa·s to 10 ^7.5 dPa·s in the molding zone A1 corresponds to a temperature of 946°C to 1200°C. Further, the viscosity of more than 10 ^7.5 dPa·s to 10 ^7.65 dPa·s in the low temperature range corresponds to a temperature of 937°C or higher and less than 946°C. Also, the viscosity of 10 ^6.7 dPa·s to 10 ^7.65 dPa·s in the mixing region corresponds to a temperature of 937°C to 1000°C. Furthermore, a viscosity of more than 10 ^7.65 dPa·s in the slow cooling zone A2 corresponds to a temperature of less than 937°C. These temperatures are measured at the center of the glass ribbon G in the width direction.

The roll 5 having the structure shown in FIG. 3 is used in the mixing zone, the low temperature zone, or the slow cooling zone A2. For example, a roll whose rotating member is made of metal is used in the forming zone A1 (excluding the mixing zone), and a roll 5 whose rotating member is made of ceramic is used in the mixing zone and slow cooling zone A2.

The roll 5 has a rotating member 51 , a rotating shaft 52 and a coolant channel 53 . The rotating member 51 is, for example, disk-shaped, and presses the widthwise end of the glass ribbon G at its outer periphery to feed the glass ribbon G in its longitudinal direction. The rotating shaft 52 is rotationally driven by the driving device 6 (see FIG. 1) to rotate the rotating member 51 . The rotating shaft 52 is made of metal, and the heat resistance of metal is low.

The rotating member 51 is made of ceramic. Since ceramics are superior in heat resistance to metals, coolant channels are not formed inside the rotating member 51 . Therefore, it is possible to prevent the coolant from cooling the glass ribbon G via the rotating member 51 . In the mixed region, especially in the low temperature region, it is possible to suppress the deterioration of the grip force.

The type of ceramic for the rotary member 51 is not particularly limited, but for example, silicon nitride (Si ₃ N ₄ ) based ceramic or the like. Silicon nitride has a high resistance to droplets of the molten metal M and vapor of the molten metal M, is resistant to adhesion of the molten metal M, and is excellent in high-temperature strength and creep properties. Silicon nitride ceramics are also excellent in that they have low reactivity with alkali-free glass.

The silicon nitride ceramic may be a sintered body obtained by sintering a molded body made of mixed powder containing silicon nitride powder and sintering aid powder. Sintering methods include normal pressure sintering and pressure sintering (including hot press sintering and gas pressure sintering). 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 as the sintering aid. .

The silicon nitride ceramic has an aluminum (Al) content of 0.1% by mass or less, preferably less than 0.1% by mass, and a magnesium (Mg) content of 0.7% by mass or less, preferably 0.7%. less than 0.9% by mass, and the content of titanium (Ti) is 0.9% by mass or less, preferably less than 0.9% by mass. When the Al content, Mg content, and Ti content are within the above ranges, the reactivity between the rotating member 51 and the glass ribbon G is low, and the rotating member 51 and the glass ribbon G are less likely to stick to each other, resulting in good durability. You get sex. The Al content, Mg content and Ti content may each be 0% by mass.

The silicon nitride ceramic has a zirconium (Zr) content of 3.5% by mass or less, preferably less than 3.5% by mass, and an yttrium (Y) content of 0.5% by mass or more, preferably 0.5% by mass. It may be more than 10% by mass, preferably less than 10% by mass. Zr and Y are components that are less likely to interdiffuse with the glass ribbon G than Al, Mg, and Ti, so they may be contained within the above ranges. Sintering of the silicon nitride powder can be promoted by containing in the above range. 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 normal pressure sintering or pressure sintering, but may be a sintered body obtained by reaction sintering. The reaction sintering method is a method of heating a compact made of metal silicon (Si) powder in a nitrogen atmosphere. Since the reaction sintering method does not use a sintering aid, a highly pure sintered body can be obtained, and the durability of the sintered body to the glass ribbon G can be improved.

As shown in FIG. 3, the outer periphery of the rotating member 51 may have a curved cross-sectional shape that protrudes radially outward over the entire periphery. The radius of curvature of the convex curve is, for example, 1 mm to 100 mm.

The rotating shaft 52 passes through an opening in the side wall 22 and is connected to the driving device 6 outside the molding furnace 2, as shown in FIG. The driving device 6 includes, for example, a motor and a speed reducer, and rotates the rotary shaft 52 . The rotating shaft 52 is inserted through a central through hole of the rotating member 51 .

The rotating shaft 52 is made of metal. Since the heat resistance of metal is low, a coolant channel 53 is formed inside the rotating shaft 52 . The coolant flowing through the coolant flow path 53 is water or the like, which transfers the heat of the rotating shaft 52 to the outside and suppresses the temperature rise of the rotating shaft 52 .

As shown in FIG. 3, a flange 54 is formed in the middle of the rotating shaft 52 . The flange 54 is formed integrally with the rotary shaft 52 and is made of metal. Therefore, the refrigerant is supplied to the inside of the flange 54 from the inside of the rotating shaft 52 . The flange 54 is provided with a synchronizing shaft 55 parallel to the rotating shaft 52 . The synchronous shaft 55 is inserted through the through hole of the rotating member 51 and rotates the rotating member 51 in synchronization with the rotating shaft 52 .

The rotary shaft 52 has a threaded shaft at its tip. A first nut 56 is attached to the screw shaft. The first nut 56 presses the rotating member 51 from the side opposite to the flange 54 . In addition, the synchronous shaft 55 has a screw shaft at its tip. A second nut 57 is attached to the screw shaft. The second nut 57 presses the rotating member 51 from the side opposite to the flange 54 .

The metal of the rotary shaft 52 and the flange 54 is formed of carbon steel or alloy steel, for example. Carbon steel is, for example, S10C, S15C, S20C or S25C described in Japanese Industrial Standards (JIS G4051-2016). The alloy steel is, for example, SCr420, SCM415, etc. described in Japanese Industrial Standards (JIS G4053-2016).

A protective film may be formed on the surface of the metal. The protective film is formed of, for example, Cr, CrN, _SiC or _Si3N4 to suppress metal corrosion. The Cr film is formed by plating, for example. On the other hand, the CrN film, SiC film and _Si3N4 film are formed by, for example _, CVD (Chemical Vapor Deposition).

Note that the rotating shaft 52 and the flange 54 may be configured to include welded portions. In this case, since the heat resistance of the welded portion is particularly low, it is necessary to sufficiently cool the welded portion with a coolant.

As shown in FIG. 1 , the molding apparatus 1 further includes a heating mechanism 7 that heats the outer circumference of the rotating member 51 . The rotating member 51 presses the widthwise end of the glass ribbon G at its outer periphery and feeds the glass ribbon G in the longitudinal direction of the glass ribbon G. As shown in FIG. Since the heating mechanism 7 heats the outer periphery of the rotating member 51, the rotating member 51 easily bites into the glass ribbon G, thereby improving the gripping force.

The heating mechanism 7 includes an irradiator 71 that irradiates the outer circumference of the rotating member 51 with a laser beam L oscillated by a light source. The illuminator 71 includes optical components such as lenses or mirrors. The irradiator 71 is attached to the side wall 22 of the molding furnace 2 or the like. Since the irradiator 71 is not positioned directly above the molten metal M, it is hardly exposed to the molten metal M vapor. Therefore, deterioration of the irradiator 71 can be suppressed. Note that the irradiator 71 may be provided outside the side wall 22 .

The laser beam L is absorbed by the outer circumference of the rotating member 51 and converted into heat to heat the outer circumference of the rotating member 51 . When the material of the rotating member 51 is silicon nitride, heat transfer in the radial direction of the rotating member 51 can be suppressed because silicon nitride has a low thermal conductivity. Therefore, the heating efficiency of the outer periphery of the rotating member 51 and the cooling efficiency of the rotating shaft 52 are good.

When the outer circumference of the rotating member 51 is heated by the laser beam L, the temperature of the contacting portion of the rotating member 51 with the glass ribbon G rises, and the gripping force on the glass ribbon G improves. Therefore, it is possible to apply tension to the hardened glass ribbon G in the width direction, thereby suppressing shrinkage of the glass ribbon G in the width direction. As a result, deformation due to shrinkage is reduced, so the flatness of the glass ribbon G is improved.

The temperature of the outer periphery of the rotating member 51 after heating is higher than the temperature of the atmosphere inside the molding furnace 2 by, for example, 1° C. to 200° C. This temperature difference is preferably 1°C to 100°C, more preferably 5°C to 70°C, even more preferably 10°C to 50°C. Further, the temperature of the outer periphery of the rotating member 51 after heating can be set, for example, in the range of 600.degree. C. to 1000.degree. C., preferably in the range of 650.degree.

The wavelength of the laser beam L is, for example, 10 nm to 10600 nm. Although the number of laser beams L is one in FIGS. 1 and 3, it may be plural. A plurality of laser beams L may be irradiated simultaneously. The oscillation method of the laser beam L may be continuous oscillation or pulse oscillation.

The light source of the laser beam L is for example a _CO2 laser, a YAG laser, an excimer laser or a _YVO4 laser. The wavelength of the _CO2 laser is 10600 nm. The wavelength of YAG laser is 266 nm, 355 nm or 1064 nm. The wavelength of the excimer laser is 157 nm, 193 nm, 248 nm, 308 nm or 351 nm. The wavelength of _YVO4 laser is 914 nm, 1064 nm or 1342 nm.

As shown in FIG. 3, rotating member 51 includes a conical tapered surface 58 . The tapered surface 58 is line-symmetrical with respect to the rotation center line R of the rotation shaft 52 . Therefore, the incident angle θ of the laser beam L with respect to the tapered surface 58 can be kept constant while the rotary shaft 52 is rotating.

The incident angle θ is, for example, 0° to 15°, preferably 0° to 10°. Since the laser beam L is always incident on the tapered surface 58 substantially perpendicularly, the energy density per unit area is high and the heating efficiency is good. Also, irregular reflection on the tapered surface 58 can be prevented, and the reflected light can be guided in a specific direction.

In order to reduce the reflectance of the laser beam L, the tapered surface 58 may be roughened by reducing the degree of polishing during finishing, blasting, or the like. Arithmetic mean roughness Ra of the tapered surface 58 is, for example, 0.1 nm to 50 μm, preferably 500 nm to 30 μm. The arithmetic mean roughness Ra is measured according to Japanese Industrial Standards (JIS B0601-2013).

The tapered surface 58 tapers outward in the width direction of the glass ribbon G (positive side in the Y-axis direction in FIG. 3). Of the pair of side walls 22 spaced apart in the Y-axis direction, the closer side wall 22 can be irradiated with the laser beam L. As shown in FIG. Since the distance between the irradiator 71 and the rotating member 51 is short, it is easy to irradiate the rotating member 51 with the laser beam L. The tapered surface 58 can be formed by grinding, for example.

(Molding device according to the first modification)
Next, with reference to FIG. 4, a molding apparatus according to a first modified example will be described. Differences between this modified example and the above-described embodiment will be mainly described below.

The heating mechanism 7 of this modified example has a heating element 72 arranged opposite to the outer circumference of the rotating member 51 and a support member 73 supporting the heating element 72 . The heating element 72 generates heat by being supplied with electric power. The power may be either direct current or alternating current. The material of the heating element 72 may be kanthal or nichrome, but is preferably SiC or Pt from the viewpoint of durability. The support member 73 keeps the distance between the heating element 72 and the rotating member 51 constant.

The heating element 72 of this modification is arranged to face the outer periphery of the rotating member 51 and does not come into contact with the rotating member 51 . Since the heating element 72 does not rotate together with the rotating member 51, power supply to the heating element 72 is easy. Since the heating element 72 does not contact the rotating member 51, the heat of the heating element 72 is transmitted to the outer periphery of the rotating member 51 by thermal radiation. The outer periphery of the rotating member 51 can easily bite into the glass ribbon G, improving the gripping force. When the material of the rotating member 51 is silicon nitride, heat transfer in the radial direction of the rotating member 51 can be suppressed because silicon nitride has a low thermal conductivity. Therefore, the heating efficiency of the outer periphery of the rotating member 51 and the cooling efficiency of the rotating shaft 52 are good.

The support member 73 includes a horizontal portion 74 arranged horizontally. A heating element 72 is attached to one end of the horizontal portion 74 . The material of the horizontal portion 74 is not particularly limited, but may be silicon nitride, for example. Since the thermal conductivity of silicon nitride is low, heat dissipation due to heat conduction can be prevented.

The support member 73 further includes a bearing portion 75 that rotatably supports the rotating shaft 52 and an arm portion 76 that connects the bearing portion 75 and the horizontal portion 74 . The bearing portion 75 is, for example, a slide bearing and has a through hole through which the rotating shaft 52 is inserted. The bearing portion 75 does not rotate together with the rotating shaft 52 . The arm portion 76 may extend obliquely upward, or may extend directly upward as shown in FIG.

According to this modification, the rotating shaft 52 and the heating element 72 are connected by the supporting member 73 . Therefore, when the rotating shaft 52 is moved to correct the arrangement of the rotating member 51 , the heating element 72 also moves following the rotating shaft 52 . Therefore, the trouble of correcting the position of the heating element 72 with respect to the rotating member 51 every time the rotating shaft 52 is moved can be saved.

The support member 73 further includes a rotation prevention portion 77 that prevents rotation of the bearing portion 75 and the arm portion 76 . One end of the rotation preventing portion 77 may be attached to the bearing portion 75, or may be attached to the arm portion 76 as shown in FIG. The other end of the anti-rotation part 77 is attached to the side wall 22 (see FIG. 1) of the molding furnace 2 . The other end of the rotation preventing portion 77 may be attached to a housing (not shown) provided around the rotating shaft 52 . The material of the anti-rotation portion 77 may be either ceramic or metal. A hole for a conductive wire may be formed inside the anti-rotation portion 77 . The conductive wire supplies power to the heating element 72 .

Support member 73 further includes bolts 78 that fasten horizontal portion 74 and arm portion 76 . A bolt 78 passes through a through hole in the arm portion 76 and is screwed into a threaded hole in the horizontal portion 74 . Since the horizontal portion 74 and the arm portion 76 are separated, the maintainability is good and the cost is low.

All of the support member 73 may be ceramic, or at least a portion of the support member 73 may be a metal member. Specifically, at least one of the horizontal portion 74, the bearing portion 75, the arm portion 76, and the rotation prevention portion 77 may be a metal member.

The metal member is made of carbon steel or alloy steel, for example. Carbon steel is, for example, S10C, S15C, S20C or S25C described in Japanese Industrial Standards (JIS G4051-2016). The alloy steel is, for example, SCr420, SCM415, etc. described in Japanese Industrial Standards (JIS G4053-2016).

By the way, compared to ceramics, metals are superior in workability, but inferior in corrosion resistance. Inside the forming furnace 2, the vapor of the molten metal M condenses on the ceiling 21 (see FIG. 1) and the condensed droplets can fall on the metal members. As a result, metal members may corrode. Therefore, a protective film 79 (a protective film of the anti-rotation portion 77 in FIG. 4) may be formed on the surface of the metal member. The protective film 79 is made of, for example, Cr, CrN, SiC, or Si ₃ N ₄ and suppresses corrosion of metal members. The Cr film is formed by plating, for example. On the other hand, the CrN film, SiC film and _Si3N4 film are formed by, for example _, CVD (Chemical Vapor Deposition).

Also, metals are inferior to ceramics in heat resistance. Therefore, a coolant channel may be formed inside the metal member. The coolant conveys the heat of the metal member to the outside and suppresses the temperature rise of the metal member.

Note that the support member 73 in FIG. 4 may have an inclined portion instead of the horizontal portion 74 . The inclined portion may extend obliquely upward or obliquely downward from the arm portion 76 with respect to the horizontal direction.

4 may include a conical tapered surface 58 (see FIG. 3) as in the above embodiment. In this case, in order to increase the heating efficiency of the outer circumference of the rotating member 51, the heating element 72 is preferably arranged to face the tapered surface.

(Molding device according to the second modification)
Next, a molding apparatus according to a second modified example will be described with reference to FIG. Differences between this modified example and the first modified example will be mainly described below.

The support member 73 of this modified example includes only a horizontal portion 74 arranged horizontally. A heating element 72 is attached to one end of the horizontal portion 74 . The other end of the horizontal portion 74 is attached to the side wall 22 (see FIG. 1) of the molding furnace 2 .

Unlike the support member 73 of the first modification, the support member 73 of this modification does not connect the rotating shaft 52 and the heating element 72 . Therefore, only one of the rolls 5 and the heating mechanism 7 can be taken out of the molding furnace 2 for maintenance.

The horizontal portion 74 of this modified example is divided into a first dividing portion 741 made of ceramic and a second dividing portion 742 made of metal. The heating element 72 is attached to the first split portion 741 made of ceramic. The material of the first dividing portion 741 is not particularly limited, but may be silicon nitride, for example. Since the thermal conductivity of silicon nitride is low, heat dissipation due to heat conduction can be prevented. Since the second dividing portion 742 is made of metal, a coolant channel is formed inside.

Also in the first modified example, the horizontal portion 74 in FIG. 4 may be divided into a ceramic first divided portion and a metal second divided portion. The second split portion is attached to the arm portion 76 with bolts 78 or the like.

Also, the support member 73 in FIG. 5 may have an inclined portion instead of the horizontal portion 74 . The inclined portion may extend obliquely upward or downward from the horizontal direction from the side wall 22 (see FIG. 1) of the molding furnace 2 .

5 may also include a conical tapered surface 58 (see FIG. 3) as in the above embodiment. In this case, in order to increase the heating efficiency of the outer circumference of the rotating member 51, the heating element 72 is preferably arranged to face the tapered surface.

(Molding device according to the third modification)
Next, a molding apparatus according to a third modified example will be described with reference to FIGS. 6 and 7A to 7C. Differences between this modified example and the above-described embodiment will be mainly described below.

The heating mechanism 7 has a heating wire 81 formed on the surface of the rotating member 51 . The heating wire 81 generates heat by supplying electric power. The power may be either direct current or alternating current. The material of the heating wire 81 may be kanthal or nichrome, but is preferably SiC or Pt from the viewpoint of durability.

Since the heating wire 81 of this modified example contacts the surface of the rotating member 51, the heat of the heating wire 81 is transmitted to the outer periphery of the rotating member 51 by heat conduction. The outer periphery of the rotating member 51 can easily bite into the glass ribbon G, improving the gripping force. Since there is no gap between the heating wire 81 and the rotating member 51, the heat transfer efficiency is less likely to fluctuate due to turbulence in the air flow, and the temperature controllability is good.

The rotating member 51 has two flat surfaces 511 and 512 perpendicular to the rotation centerline R of the rotating member 51 . One flat surface 511 is a surface directed inward in the width direction of the glass ribbon G. As shown in FIG. A concave portion 513 is formed in the flat surface 511 . The remaining one flat surface 512 is a surface directed outward in the width direction of the glass ribbon G. As shown in FIG.

The heating wire 81 is embedded in the recess 513 of the flat surface 511 . Also, the heating wire 81 is formed on the flat surface 512 . Note that the recess 513 may be formed on either of the two flat surfaces 511 and 512, or may not be formed on either. Although the heating wire 81 is formed on both sides of the rotating member 51 in FIG. 6, it may be formed only on one side.

By the way, since the heating wire 81 of this modification is formed on the surface of the rotating member 51 , it rotates together with the rotating member 51 . Therefore, the heating mechanism 7 has a brush electrode 82 shown in FIGS. 7A and 7C or a roller electrode 83 shown in FIG. 7B as an electrode for supplying electric power to the heating wire 81 . The heating wire 81 is formed in an annular shape around the rotation center line R of the rotating shaft 52 so as to always receive electric power while the rotating member 51 is rotating.

Although the apparatus for manufacturing a glass sheet and the method for manufacturing a glass sheet according to the present disclosure have been described above, the present disclosure is not limited to the above embodiments and the like. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These also naturally belong to the technical scope of the present disclosure.

For example, the forming apparatuses 1 of the above embodiments and modifications obtain the glass ribbon G by the float method, but the glass ribbon may be obtained by the fusion method. In the fusion method, molten glass is continuously supplied to the grooves of the gutter, and the molten glass that overflows on both the left and right sides of the gutter is allowed to flow down along the left and right sides of the gutter, join at the lower edge of the gutter, and form a band plate. shape. Fusion process rolls deliver the glass ribbon in the vertical direction.

1 Forming Device 2 Forming Furnace 20 Bathtub 21 Ceiling 22 Side Wall 3 Heater 5 Roll 51 Rotating Member 52 Rotating Shaft 53 Refrigerant Flow Path 58 Tapered Surface 7 Heating Mechanism 71 Irradiator 72 Heating Element 73 Supporting Member 74 Horizontal Section 75 Bearing Section 76 Arm Section 78 bolt 79 protective film 81 heating wire 82 brush electrode 83 roller electrode G glass ribbon M molten metal

Claims (14)

It has a rotating member made of ceramic, a rotating shaft for rotating the rotating member, and a coolant channel formed inside the rotating shaft, and a width direction of a band-shaped glass ribbon on the outer periphery of the rotating member. A roll that presses the end portion and sends out the glass ribbon in the longitudinal direction of the glass ribbon;
a heating mechanism for heating the outer circumference of the rotating member;
with
The apparatus for manufacturing a glass sheet, wherein the heating mechanism includes an irradiator that irradiates the outer circumference of the rotating member with a laser beam. The rotating member includes a conical tapered surface that is symmetrical with respect to the center line of rotation of the rotating shaft,
2. The apparatus for manufacturing a glass sheet according to claim 1, wherein the incident angle of said laser beam to said tapered surface is 0° to 15°. The apparatus for manufacturing a glass plate according to claim 2, wherein the tapered surface tapers outward in the width direction of the glass ribbon. It has a rotating member made of ceramic, a rotating shaft for rotating the rotating member, and a coolant channel formed inside the rotating shaft, and a width direction of a band-shaped glass ribbon on the outer periphery of the rotating member. A roll that presses the end portion and sends out the glass ribbon in the longitudinal direction of the glass ribbon;
a heating mechanism for heating the outer periphery of the rotating member;
with
The apparatus for manufacturing a glass sheet, wherein the heating mechanism has a heat generating element arranged opposite to the outer circumference of the rotating member, and a support member supporting the heat generating element. The support member includes a horizontal portion arranged horizontally,
The apparatus for manufacturing a glass plate according to claim 4, wherein the heating element is attached to the horizontal portion. The apparatus for manufacturing a glass plate according to claim 5, wherein the support member includes a bearing portion that rotatably supports the rotating shaft, and an arm portion that connects the bearing portion and the horizontal portion. The support member further includes a bolt that fastens the horizontal portion and the arm portion,
7. The apparatus for manufacturing a glass sheet according to claim 6, wherein said bolt passes through a through hole of said arm portion and is screwed into a screw hole of said horizontal portion. At least part of the support member is a metal member made of carbon steel or alloy steel,
The glass plate manufacturing apparatus according to any one of claims 4 to 7, wherein a protective film of Cr, CrN, SiC or Si ₃ N ₄ is formed on the surface of the metal member. The apparatus for manufacturing a glass plate according to any one of claims 4 to 8, wherein the material of the heating element is SiC or Pt. It has a rotating member made of ceramic, a rotating shaft for rotating the rotating member, and a coolant channel formed inside the rotating shaft, and a width direction of a band-shaped glass ribbon on the outer periphery of the rotating member. A roll that presses the end portion and sends out the glass ribbon in the longitudinal direction of the glass ribbon;
a heating mechanism for heating the outer circumference of the rotating member;
with
The apparatus for manufacturing a glass plate, wherein the heating mechanism has a heating wire formed on the surface of the rotating member. The rotating member has a flat surface perpendicular to the centerline of rotation of the rotating member,
The apparatus for manufacturing a glass plate according to claim 10, wherein the heating wire is formed on the flat surface of the rotating member. The rotating member has a flat surface perpendicular to the rotation center line of the rotating member and a recess formed in the flat surface,
The apparatus for manufacturing a glass plate according to claim 10, wherein the heating wire is embedded in the concave portion of the rotating member. The apparatus for manufacturing a glass plate according to claim 11 or 12, wherein the flat surface is at least one of a surface facing inward in the width direction of the glass ribbon and a surface facing outward in the width direction of the glass ribbon. A method for manufacturing a glass plate using the manufacturing apparatus according to any one of claims 1 to 13.

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