JP2019064903A - Method for manufacturing glass plate - Google Patents

Abstract

To form the stable flow of a glass plate during a short time even when the width of the tip portion of the glass plate before flowing down at first from a molding to form the shape of the glass plate does not reach a width capable of holding conveyance roller pairs positioned on both sides of a conveying path.SOLUTION: The method for manufacturing a glass plate comprises a molding step of molding the glass plate using an overflow down draw method and a conveyance step of holding regions on both sides of the glass plate in the width direction by a plurality of conveyance roller pairs to convey the glass plate. Before starting the molding step, the width of a glass body without reaching a width capable of holding the conveyance roller pairs positioned on both sides of the conveying path before flowing down at first from the molding to form the shape of the glass plate is held on the conveyance roller pairs by sandwiching the glass body by a pair of auxiliary rollers provided at a place where the temperature of the glass body is from a temperature of the glass transition point+50°C to the strain point and pressing it from both sides to expand a width capable of holding the conveyance roller.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method of manufacturing a glass sheet.

  In the method of manufacturing a glass sheet using the downdraw method, in the forming step, the molten glass is overflowed from the formed body and formed into a sheet glass (glass sheet) extending continuously. Then, in the subsequent cooling step, the glass sheet is drawn downward while being pinched by the transport roller pair, so that the glass sheet is stretched to a desired thickness and the glass sheet is warped so that no distortion occurs inside. In order not to do so, the glass plate is cooled. Thereafter, the glass plate is cut into a predetermined size, and after washing and inspection, the glass plate satisfying the predetermined quality is regarded as a accepted product as a glass substrate for a display device such as a liquid crystal display device.

  For example, a forming apparatus for forming a glass sheet by flowing molten glass formed by melting a glass material down a side wall of a formed body using an overflow downdraw method, and areas on both sides in the width direction of the glass sheet obtained by forming And a plurality of annealing rollers provided in the conveyance direction of the glass plate, and the annealing device includes an annealing furnace for conveying and cooling the glass plate downward, and the plurality of cooling rollers in the annealing chamber DESCRIPTION OF RELATED ART The manufacturing method of the glass plate which can suppress that a waveform-shaped deformation | transformation arises in the adjacent area | region adjacent to the part of the glass plate pinched by the conveyance roller is known (patent document 1).

JP, 2013-136515, A

  In the above manufacturing method, both ends in the width direction of the formed glass sheet are cooled faster than the central part in the width direction of the glass sheet, and the temperature of the glass sheet is glass transition so that plastic deformation does not occur in the glass sheet. By applying tension to the glass sheet in the conveying direction in a temperature range from the point to the glass softening point, wave-like deformation occurs in the adjacent area adjacent to the portion of the glass sheet nipped by the conveying roller pair You can suppress that. The pair of transport rollers sandwiches the surface on both sides of the glass plate, and while rotating the glass plate by itself while pressing the glass plate with a constant force, transports the glass plate. Thereby, the conveyance speed of a glass plate can be controlled and tension can be exerted on the glass plate in the conveyance direction.

In such a slow cooling device, although it is possible to cool while continuously conveying a continuous glass sheet, at the start of operation where molten glass starts to flow in the forming device, the tip portion of the first formed glass sheet Often do not have enough width. For example, the molten glass that first overflows from the groove of the formed body does not overflow uniformly, and the tip portion of the first glass sheet introduced by gravity from the formed body into the annealing furnace has a target constant width. In contrast, the width is extremely narrow. That is, the width of the tip portion does not reach the nipping width of the transport roller pair located on both sides of the transport path of the glass sheet. For this reason, it is necessary to wait until the glass plate formed by the molded body has a width capable of holding the pair of conveyance rollers without being held by the conveyance roller. However, it takes time until it becomes a glass plate with such a width, and the amount of molten glass to be wasted is large, and the tip of the glass body which flows down from the molded body and falls under its own weight falls down the inside of the annealing device. As a pendulum swings up and down like a pendulum by the upward air flow from the top, it may contact a component such as a temperature control device in a lehr, or in the worst case, may adhere to the component and damage the component.
Such operational disclosure problems can always occur before producing a stable glass sheet.

  Therefore, according to the present invention, when forming a glass sheet, the width of the front end portion of the glass sheet is positioned on both sides of the conveyance path before flowing down from the formed body first to form the glass sheet. It is an object of the present invention to provide a method for producing a glass sheet which makes it possible to create a stable flow of glass sheet in a short time even if the width does not reach the nipping width of the above.

One aspect of the present invention is a method for producing a glass sheet. The manufacturing method of the said glass plate is
Forming the molten glass flowing down from the forming body using an overflow down draw method into a continuous glass sheet;
And a conveying step of conveying the glass sheet downward while sandwiching the regions on both sides in the width direction of the glass sheet with a plurality of conveyance roller pairs provided in the conveyance path of the glass sheet.
Prior to the start of the forming step of the glass plate, it does not reach the nipping width of the pair of conveying rollers positioned on both sides of the conveying path before flowing down from the formed body first and becoming the shape of the glass plate The width of the glass body is determined by the pair of auxiliary rollers provided in a temperature range in which the temperature of the glass body is between the temperature of the glass transition point + 50 ° C. and the strain point. The sheet is nipped by the pair of conveying rollers by pressing the both sides across the sheet to widen the nipping width of the conveying roller.

The transport path extends downward from the lower end of the molded body,
The auxiliary roller is preferably provided at a position on the conveyance path between the lower end portion of the formed body and the most upstream conveyance roller pair closest to the formed body among the conveyance roller pair.
Further, the transport roller pair is located closest to the molded body among the transport roller pair, and sandwiches and cools both sides in the width direction of the glass plate, thereby the width direction of the glass plate A pair of cooling rollers for making the viscosity of the region on both sides (side portions) of 10 ^9.0 poise or more, and a plurality of pulling-downs provided in the space on the downstream side of the conveyance direction of the glass sheet with respect to the cooling roller pair A pair of rollers, wherein the auxiliary roller is provided on a conveyance path between the pair of cooling rollers and the pair of pulling rollers of the pulling roller pair positioned most upstream in the feeding direction It is also preferred that

  It is preferable that the pair of auxiliary rollers gradually reduce the distance between the pair of auxiliary rollers after the tip of the glass body passes between the pair of auxiliary rollers.

  After the glass body is nipped by the transport roller pair, the distance between the pair of auxiliary rollers is increased to retract the pair of auxiliary rollers to a position not in contact with the glass body and the glass substrate. Preferably, the forming step and the cooling step are performed.

  It is preferable that the roller width of the auxiliary roller is wider than the product width of the glass plate and narrower than the separation distance of the transport roller pair.

  According to the above-described method for manufacturing a glass plate, even if the width of the front end portion of the glass plate does not reach the nipping width of the pair of transport rollers positioned on both sides of the transport path, it is stable in a short time It is possible to make it possible to create a flow of glass sheet.

It is a flowchart of the manufacturing method of the glass plate which concerns on one Embodiment. It is a schematic diagram which shows the manufacturing apparatus of the glass plate used by the manufacturing method of a glass plate. It is a schematic diagram (cross section) of an outline of a molding device. It is a schematic diagram (side view) of the outline of a forming device. It is a block diagram showing an example of composition of a control device in one embodiment. It is a figure explaining an example of the auxiliary | assistant roller used by this embodiment. It is a figure explaining the example of the function of the auxiliary | assistant roller used by this embodiment. It is a figure explaining the example of the auxiliary | assistant roller provided in the different place from the auxiliary | assistant roller shown in FIG. 7 used by this embodiment.

  Hereafter, the manufacturing method of the glass plate of one Embodiment, and the manufacturing apparatus of a glass plate are demonstrated in detail. In the method of manufacturing a glass plate according to one embodiment, for example, a glass substrate for a TFT display is manufactured. Glass sheets are manufactured using an overflow downdraw method. Hereinafter, the manufacturing method of the glass plate concerning one embodiment is explained, referring to drawings.

(1) Outline of Method of Manufacturing Glass Plate First, with reference to FIGS. 1 and 2, a plurality of steps included in the method of manufacturing a glass plate and a manufacturing apparatus 100 of a glass plate used in the plurality of steps will be described. As shown in FIG. 1, the method for producing a glass plate mainly includes a melting step S1, a clarifying step S2, a forming step S3, a cooling step S4, and a cutting step S5.

Melting process S1 is a process in which the raw material of glass is melted. The glass raw material is formulated to have a desired composition, and then introduced into the melting device 11 disposed upstream, as shown in FIG. The glass material comprises, for example, a composition of SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , CaO, SrO, BaO or the like. Specifically, a glass material having a glass strain point of 660 ° C. or higher is used. The raw material of the glass is melted by the melting device 11 to become the molten glass FG. The melting temperature is adjusted according to the type of glass. In the present embodiment, the glass material is melted at 1500 ° C to 1650 ° C. The molten glass FG is sent to the refining device 12 through the upstream pipe 23.

  The fining step S2 is a step of removing air bubbles in the molten glass FG. The molten glass FG from which bubbles have been removed in the fining device 12 is then sent to the forming device 40 through the downstream pipe 24.

  The forming step S3 is a step of forming the molten glass FG into a sheet glass SG which is a sheet-like glass. Specifically, the molten glass FG overflows from the groove of the formed body 41 after being continuously supplied to the formed body 41 included in the forming apparatus 40. The overflowed molten glass FG flows down along the surface of the formed body 41. Thereafter, the molten glass FG is joined at the lower end portion 41 a of the formed body 41 and formed into a sheet glass SG. The sheet glass SG has a side (ear, end) located at the end in the width direction, and a central region in the width direction sandwiched between the sides. The thickness of the side portion of the sheet glass SG is formed thicker than the thickness of the central region. The central region of the sheet glass SG is a region to be a glass plate which is a final product having a constant thickness. When the thickness of the central region of the sheet glass SG is to be formed into a thin plate of 0.4 mm or less, the thickness of the side of the sheet glass SG is formed thinner than before.

  The cooling step S4 is a step of cooling (slow cooling) the sheet glass SG. The sheet glass SG is cooled to a temperature close to room temperature through the cooling step S4. In addition, according to the state of cooling in cooling process S4, the thickness (plate thickness) of a glass plate, the curvature amount of a glass plate, and the distortion amount of a glass plate are determined.

  The cutting step S5 is a step of cutting the sheet glass SG having a temperature close to room temperature into a predetermined size.

  In addition, the sheet glass SG cut | judged to predetermined | prescribed magnitude | size passes through processes, such as an end surface process, after that. Hereinafter, the sheet glass SG is referred to as a glass plate.

  Hereinafter, with reference to FIGS. 3-5, the structure of the shaping | molding apparatus 40 contained in the manufacturing apparatus 100 of a glass plate is demonstrated. In the present embodiment, the width direction of the sheet glass SG means a direction intersecting the direction in which the sheet glass SG flows (flow direction), that is, the horizontal direction.

(2) Configuration of Forming Apparatus First, FIGS. 3 and 4 show a schematic configuration of the forming apparatus 40. FIG. FIG. 3 is a cross-sectional view of the forming apparatus 40. As shown in FIG. FIG. 4 is a side view of the forming apparatus 40. FIG.

  The forming apparatus 40 has a passage through which the sheet glass SG passes, and a space surrounding the passage. A space surrounding the passage is composed of an overflow chamber 20, a forming chamber 30, and a cooling chamber 80.

  The overflow chamber 20 is a space for forming the molten glass FG sent from the fining device 12 into the sheet glass SG. Sheet glass SG is a glass plate which extends continuously.

  The forming chamber 30 is disposed below the overflow chamber 20 and is a space for adjusting the thickness and the amount of warpage of the sheet glass SG. In the forming chamber 30, a part of the cooling process is performed. The molten glass FG flows down along the surface of the formed body 41, joins at the lower end portion 41a of the formed body 41 and is formed into the sheet glass SG, but at the downstream of the lower end portion 41a of the formed body 41, the sheet The temperature of the glass SG gradually decreases. The forming chamber 30 is separated from the overflow chamber 20 by a partition member 50.

  The cooling chamber 80 is disposed below the forming chamber 30 and is a space for adjusting the amount of strain of the sheet glass SG. Specifically, in the cooling chamber 80, the sheet glass SG which has passed through the inside of the forming chamber 30 is cooled to a temperature near room temperature through the annealing point and the glass strain point. The cooling chamber 80 is divided by the heat insulating member 80a with respect to the forming chamber 30, and the inside of the cooling chamber 80 is further divided by the heat insulating member 80b into a plurality of spaces.

  The molding apparatus 40 mainly includes a molded body 41, a partition member 50, a cooling roller 51, a temperature control unit 60, pulling rollers 81a to 81g, heaters 82a to 82g, and a cutting device 90. ing. Furthermore, the molding device 40 includes a control device 500 (see FIG. 5). The control device 500 controls the drive unit of each configuration included in the molding device 40. The cooling roller 51 and the pull-down rollers 81a to 81g are conveyance rollers provided in the conveyance direction of the glass plate in the regions on both sides in the width direction of the glass plate and conveying the glass plate downward.

  Hereinafter, each component included in the molding apparatus 40 will be described in detail.

(2-1) Molded Body The molded body 41 is provided in the overflow chamber 20. The formed body 41 forms the molten glass FG into a sheet-like glass plate (sheet glass SG) by causing the molten glass FG to overflow from the groove.

  As shown in FIG. 3, the molded body 41 has a substantially pentagonal cross-sectional shape (shape similar to a wedge shape). The substantially pentagonal tip corresponds to the lower end portion 41 a of the molded body 41.

  In addition, the molded body 41 has an inlet 42 at a first end (see FIG. 4). The inflow port 42 is connected to the above-described downstream pipe 24, and the molten glass FG that has flowed out of the fining device 12 is poured into the formed body 41 from the inflow port 42. Grooves 43 are formed in the molded body 41. The groove 43 extends in the longitudinal direction of the molded body 41. Specifically, the groove 43 extends from the first end to a second end that is the opposite end of the first end. More specifically, the grooves 43 extend in the left-right direction in FIG. The groove 43 is formed so as to be deepest in the vicinity of the inflow port 42 and gradually shallow as it approaches the second end. The molten glass FG poured into the formed body 41 overflows from the pair of top portions 41 b and 41 b of the formed body 41 and flows down along the pair of side surfaces (surfaces) 41 c and 41 c of the formed body 41. Thereafter, the molten glass FG merges at the lower end portion 41 a of the formed body 41 to form a sheet glass SG.

At this time, the liquidus temperature of the sheet glass SG at the lower end portion 41a of the formed body 41 is 1100 ° C. or more, the liquidus viscosity is 2.5 × 10 ⁵ poise or more, and more preferably, the liquidus temperature is 1160 The liquid phase viscosity is 1.2 × 10 ⁵ poise or more. Moreover, the viscosity of the side part (ear part, edge part) of the sheet glass SG in the lower end part 41a of the molded object 41 is less than 10 ^5.7 Poise.

(2-2) Partition Member The partition member 50 is a member that blocks the transfer of heat from the overflow chamber 20 to the forming chamber 30. The partition member 50 is disposed in the vicinity of the joining point of the molten glass FG. Moreover, as shown in FIG. 3, the partition member 50 is arrange | positioned at the thickness direction both sides of the sheet glass SG which the molten glass FG merged and formed at the confluence | merging point. The partition member 50 is a heat insulating material. The partition member 50 blocks the transfer of heat from the upper side to the lower side of the partition member 50 by partitioning the upper atmosphere and the lower atmosphere of the joining point of the molten glass FG.

(2-3) Cooling roller (conveying roller)
The cooling roller 51 is provided in the forming chamber 30. More specifically, the cooling roller 51 is disposed immediately below the partition member 50. The cooling rollers 51 are disposed on both sides in the thickness direction of the sheet glass SG and on both sides in the width direction of the sheet glass SG. The cooling rollers 51 disposed on both sides in the thickness direction of the sheet glass SG operate in pairs. That is, the both sides (width direction both ends) of sheet glass SG are clamped by fixed power with two pairs of cooling rollers 51, 51 ,.

The cooling roller 51 is cooled by the air flowing through a pipe passed through the inside, a refrigerant. The cooling roller 51 contacts the side portions (ears, ends) R, L of the sheet glass SG and rapidly cools the side portions (ears, ends) R, L of the sheet glass SG by heat conduction (quenching step ). The viscosity of the side portions R and L of the sheet glass SG in contact with the cooling roller 51 is not less than a predetermined value (specifically, 10 ^9.0 poise).

  The cooling roller 51 is rotationally driven by a cooling roller drive motor 390 (see FIG. 5). The cooling roller 51 cools the side portions R and L of the sheet glass SG and functions as a conveyance roller for pulling the sheet glass SG downward.

(2-4) Temperature Adjustment Unit The temperature adjustment unit 60 is provided in the forming chamber 30, and is a unit for cooling the sheet glass SG to near the annealing point. The temperature adjustment unit 60 has a plurality of cooling units 61-65. The plurality of cooling units 61 to 65 are arranged in the width direction of the sheet glass SG and in the flow direction of the sheet glass SG. Specifically, the plurality of cooling units 61 to 65 include central region cooling units 61 to 63 and side cooling units 64 and 65. The central area cooling units 61 to 63 air-cool the central area CA of the sheet glass SG. Here, the central region of the sheet glass SG is a central portion in the width direction of the sheet glass SG, and is a region including the effective width of the sheet glass SG and the vicinity thereof. In other words, the central region of the sheet glass SG is a portion sandwiched by both sides (both-ears, both ends) R and L of the sheet glass SG. The central area cooling units 61 to 63 are arranged along the flow direction at a position facing the surface of the central area CA of the sheet glass SG.

(2-5) Pull-down roller (conveying roller)
The pulling rollers (conveying rollers) 81 a to 81 g are provided in the cooling chamber 80 and pull the sheet glass SG having passed through the inside of the forming chamber 30 in the flow direction of the sheet glass SG. The pulling rollers 81a to 81g are disposed inside the cooling chamber 80 at predetermined intervals along the flow direction. A plurality of pulling-down rollers 81a to 81g are disposed on both sides in the thickness direction of sheet glass SG (see FIG. 3) and on both sides in the width direction of sheet glass SG (see FIG. 4). That is, the pulling rollers 81a to 81g hold the sheet glass SG while gripping both sides (both ears, both ends) R and L in the width direction of the sheet glass SG and both sides in the thickness direction of the sheet glass SG with a constant force. Pull SG down.

  The pulling rollers 81a to 81g are driven by a pulling roller drive motor 391 (see FIG. 5). The pulling rollers 81a to 81g rotate inward with respect to the sheet glass SG.

(2-6) Heater The heater 82 (82a to 82g) is provided inside the cooling chamber 80, and adjusts the temperature of the internal space of the cooling chamber 80. Specifically, a plurality of heaters 82a to 82g are disposed in the flow direction of the sheet glass SG and in the width direction of the sheet glass SG. More specifically, seven heaters are disposed in the flow direction of the sheet glass SG, and seven heaters are disposed in the width direction of the sheet glass. The seven heaters arranged in the width direction include a central area CA of the sheet glass SG and side portions (ears and ends) R and L of the sheet glass SG, including a holding area held by the pulling rollers 81a to 81g. Each is heat-treated. The outputs of the heaters 82a to 82g are controlled by a control device 500 described later. Thereby, the ambient temperature in the vicinity of the sheet glass SG passing through the inside of the cooling chamber 80 is controlled. The ambient temperature in the cooling chamber 80 is controlled by the heaters 82a to 82g, whereby temperature control of the sheet glass SG is performed. Further, the temperature control causes the sheet glass SG to transition from the viscous region to the elastic region through the visco-elastic region. As described above, in the cooling chamber 80, the temperature of the sheet glass SG is cooled from the temperature near the annealing point to the temperature near room temperature by the control of the heaters 82a to 82g. Here, the annealing point is a temperature at which the viscosity is 10 ¹³ Poise, and is, for example, 715.0 ° C. here.

(2-7) Cutting Device The cutting device 90 cuts the sheet glass SG cooled to a temperature near room temperature in the cooling chamber 80 into a predetermined size. The cutting device 90 cuts the sheet glass SG at predetermined time intervals. Thereby, the sheet glass SG becomes a plurality of glass plates. The cutting device 90 is driven by a cutting device drive motor 392 (see FIG. 5).
Thus, when manufacturing a glass plate with the manufacturing apparatus 100 of a glass plate, the formation process of shape | molding sheet glass SG using the overflow down draw method from molten glass FG, the area | region of the both sides of the width direction of a glass plate A conveyance step of conveying the sheet glass SG downward is performed while being sandwiched by a plurality of conveyance roller pairs provided in the conveyance direction of the sheet glass SG. In the present embodiment, the sheet glass is cooled in the transport step.

(2-8) Control Device The control device 500 is configured of a CPU, a RAM, a ROM, a hard disk and the like, and controls various devices included in the glass plate manufacturing apparatus 100. FIG. 5 is a block diagram showing an example of the configuration of the control device 500 according to an embodiment.

  Specifically, as shown in FIG. 5, the control device 500 includes various sensors (eg, thermocouple 380, roller pressure sensor 382) and switches (eg, main power switch 381) included in the glass plate manufacturing apparatus 100. Etc.), the temperature control unit 60, heaters 82a to 82g, cooling roller drive motor 390, pulldown roller drive motor 391, cutting device drive motor 392, cooling roller position control motor 393, pulldown roller position control motor Control of 394a to 394g, etc. is performed. The cooling roller position control motor 393 is a motor for moving the position of the cooling roller 51 in order to control the position of the cooling roller 51, and the pulling roller position control motors 394a to 394g are pulling rollers 81a to 81g described later. It is a motor for moving the positions of the pull-down rollers 81a to 81g to perform position control. The roller pressure sensor 382 is a sensor that measures the force with which the cooling roller 51 and the pull-down rollers 81a to 81g press the sheet glass SG.

When cooling the sheet glass SG transported to the cooling chamber 80, the control device 500 is a thermocouple so that the temperature distribution in the width direction at each position of the transport path of the sheet glass SG achieves a target. Based on the measurement result of 380, the temperature of the temperature adjustment unit 60 and the heaters 82a to 82g is adjusted. Thereby, the deformation | transformation of the wave shape of the sheet glass SG, the distortion of the sheet glass SG, and curvature can be suppressed.
The control device 500 further performs position control of the cooling roller 51 and the pull-down rollers 81 a to 81 g using the cooling roller position control motor 393 and the pull-down roller position control motors 394 a to 394 g.

  When performing a stable glass plate manufacturing method using such a glass plate manufacturing apparatus 100, a molten glass that first overflows from the groove 43 of the molded body 41 at the start of operation before the stable glass plate is manufactured. The FG does not overflow uniformly, and the tip portion of the first sheet glass SG introduced by gravity from the molded body 41 into the forming chamber 30 and the cooling chamber 80 in the forming apparatus 40 has a target constant width. Very narrow. That is, the width of the tip portion can hold a pair of cooling roller 51 and pull-down rollers 81a-81g (hereinafter referred to collectively as cooling roller 51 and pull-down rollers 81a-81g) located on both sides of the conveyance path. It does not reach the width. Therefore, the sheet glass SG formed by the molded body 41 can be held by the pair of conveying rollers such as the cooling roller 51 and the pulling rollers 81a to 81g without being held by the conveying rollers such as the cooling roller 51 and the pulling rollers 81a to 81g. You need to wait for the width. However, it takes time until the sheet glass SG has such a width, and the amount of molten glass FG to be wasted is large. Further, the front end portion of the sheet glass SG which flows down from the molded body 41 and falls by its own weight is swayed back and forth and right and left like a pendulum by the upward air flow from the lower side to the upper side in the forming chamber 30 and the cooling chamber 80. The temperature adjustment unit 60 in the chamber 80 may come into contact with the components of the heaters 82a to 82g, or in the worst case, may adhere to the components and damage the components.

For this reason, in the present embodiment, auxiliary rollers are provided in the forming chamber 30 and the cooling chamber 80. FIG. 6 is a view for explaining an example of the auxiliary rollers 52a and 52b, and FIG. 7 is a view for explaining an example of the function of the auxiliary rollers 52a and 52b used in the present embodiment. FIG. 6 shows a cooling roller 51 as an example of the conveyance roller.
The auxiliary rollers 52 a and 52 b are provided on the side of the molded body 41 with respect to the cooling roller 51. That is, the auxiliary rollers 52 a and 52 b are provided between the lower end portion 41 a of the molded body 41 and the cooling roller 51. Before the start of the forming process of the sheet glass SG, it is possible to hold the pair of cooling rollers 51 (conveying rollers) located on both sides of the conveying path before first flowing down from the molded body 41 to form the sheet glass SG. By sandwiching the glass body across the entire width of the glass body, the width of the glass body which does not reach such a width is expanded to the sandwichable width of the cooling roller 51 (conveying roller). Specifically, the auxiliary rollers 52a and 52b press from both sides sandwiching the glass body 85 (see FIG. 6) falling from above with its own weight, and spread it to a width where the cooling roller 51 (conveying roller) can be held. As a result, the pair (conveying roller pair) of the cooling roller 51 is nipped. The auxiliary rollers 52a and 52b are provided in a temperature range in which the temperature of the glass body 85 is between the temperature of the glass transition point + 50 ° C. and the strain point. Since the auxiliary rollers 52a and 52b are provided in such a place, the sheet glass SG whose width is expanded is not broken. The strain point is the temperature at which the viscosity is 10 ^14.5 poise.
The auxiliary rollers 52a and 52b are rotated by an auxiliary roller drive motor (not shown) which is driven according to a control signal transmitted from the control device 500, although not shown.

  In the forming chamber 30 and the cooling chamber 80, as shown in FIG. 3, the conveyance path of the sheet glass SG extends downward from the lower end portion 41a of the formed body 41. In this case, as shown in FIG. 7, the auxiliary rollers 52a and 52b are the lower end portion 41a of the formed body 41 on the conveyance path, and the cooling roller 51 closest to the formed body 41 of the conveyance roller pair (most upstream conveyance roller Preferably, it is provided at a place between the pair). The cooling roller 51 is first important in cooling both ends of the sheet glass SG to prevent the sheet glass SG from being bent or warped. For this reason, it is preferable to provide the auxiliary rollers 52a and 52b in the above-mentioned place from the point which can make the glass body 85 into sheet glass SG of an appropriate shape promptly.

FIG. 8 is a view for explaining an example of auxiliary rollers 52a and 52b provided in a place different from the auxiliary rollers 52a and 52b shown in FIG. 7 which are used in the present embodiment. Auxiliary rollers 52a and 52b may be provided at the locations shown in FIG. The auxiliary rollers 52a and 52b shown in FIG. 8 are provided between the cooling roller 51 and the pulling roller 81a.
That is, the forming device 40 is positioned closest to the formed body 41 as a conveyance roller pair for holding the side portions R and L of the sheet glass SG and conveying the sheet glass SG, and the side portions R and L of the sheet glass SG The pair of cooling rollers 51 which make the viscosity of the area of the sheet glass SG side portions R and L 10 ⁹ poise or more by cooling the sheet glass SG with respect to the pair of cooling rollers 51 A pair of pulling rollers 81a to 81g provided in a cooling chamber 80 (a space for cooling the sheet glass SG from a temperature near the annealing point to a temperature near room temperature), which is a space on the side, is provided. At this time, the auxiliary rollers 52a and 52b are provided on the conveyance path between the pair of cooling rollers 51 and the pair of pulling rollers 81a positioned most upstream in the feeding direction among the pair of pulling rollers 81a to 81g. There is. Also in this case, the glass body 85 can be made into the sheet glass SG of the appropriate shape by the auxiliary rollers 52a and 52b at the most upstream location of the cooling chamber 80 or just before entering the cooling chamber 80. . For this reason, it is possible to create a stable sheet glass SG flow in a short time.

  After the tip of the glass body 85 passes between the pair of auxiliary rollers 52a and 52b, the pair of auxiliary rollers 52a and 52b move so as to gradually narrow the distance between the pair of auxiliary rollers 52a and 52b. Is preferred. Thereby, the glass body 85 can be reliably pinched and passed between the auxiliary rollers 52a and 52b. It is preferable that such movement of the auxiliary rollers 52a and 52b be performed by driving an auxiliary roller drive motor (not shown) in accordance with a control signal transmitted from the control device 500.

  After the glass body 85 is nipped by the pair of cooling rollers 51 (conveying roller pair), the distance between the pair of auxiliary rollers 52a and 62b is increased to form the pair of auxiliary rollers 52a and 52b as the glass body 85 and the sheet glass It is preferable that the forming step S3 and the cooling step S4 be performed while being retracted to a position not in contact with the SG. It becomes unnecessary to widen the width of the glass body 85 of the auxiliary rollers 52a and 52b once the sheet glass SG is sandwiched by the cooling roller 51 and the pulling-down rollers 81a to 81g. Moreover, the contact of the sheet glass SG with the auxiliary rollers 52a and 52b is an obstacle for controlling the temperature distribution of the sheet glass SG. For this reason, the auxiliary rollers 52a and 52b are retracted to a position not in contact with the glass body 85 and the sheet glass SG from the point of being able to transport and cool the stable sheet glass SG, and the forming step S3 and the cooling step S4. It is preferable to The movement of the auxiliary rollers 52a and 52b is preferably performed by driving an auxiliary roller drive motor (not shown) in accordance with a control signal transmitted from the control device 500.

  Further, it is preferable that the roller width of the auxiliary rollers 52a and 52b be wider than the product width of the glass plate to be the final product, and narrower than the separation distance of the pair of conveying rollers such as the cooling roller 51 and the pulling rollers 81a to 81g. By setting the widths of the auxiliary rollers 52a and 52b in the above-mentioned range, the width of the glass body can be easily held by the transport rollers without increasing the width more than necessary.

  As mentioned above, although the manufacturing method of the glass plate of this invention was demonstrated in detail, this invention is not limited to the said embodiment, Of course in the range which does not deviate from the main point of this invention, various improvement and changes may be made It is.

DESCRIPTION OF SYMBOLS 11 Melt apparatus 12 Fining apparatus 40 Molding apparatus 41 Molding body 51 Cooling roller 52a, 52b Auxiliary roller 60 Temperature adjustment unit 81a-81g Pull down roller 82a-82g Heater 85 Glass body 90 Cutting device 91 Control device 100 Glass plate manufacturing apparatus

Claims (6)

Forming the molten glass flowing down from the forming body using an overflow down draw method into a continuous glass sheet;
And conveying the glass sheet downward while sandwiching the regions on both sides in the width direction of the glass sheet between a plurality of conveyance roller pairs provided in the conveyance path of the glass sheet,
Prior to the start of the forming step of the glass plate, it does not reach the nipping width of the pair of conveying rollers positioned on both sides of the conveying path before flowing down from the formed body first and becoming the shape of the glass plate The glass body is spread over the entire width of the glass body by a pair of auxiliary rollers provided in a temperature range where the temperature of the glass body is between the temperature of the glass transition temperature + 50 ° C. and the strain point. A manufacturing method of a glass plate characterized by pinching with said conveyance roller pair by pressing across from both sides and expanding it to the nipping width of said conveyance roller. The transport path extends downward from the lower end of the molded body,
The auxiliary roller according to claim 1, wherein the auxiliary roller is provided at a position on the conveyance path between the lower end of the formed body and the first conveyance roller pair closest to the formed body among the conveyance roller pair. Glass plate manufacturing method. The transport roller pair is located closest to the molded body among the transport roller pair, and sandwiches and cools both sides in the width direction of the glass plate to thereby cool the both sides in the width direction of the glass plate. wherein the cooling roller pair viscosity to more than 10 ^{9.0 poise} of regions, and a plurality of pull down roller pair relative to the cooling rollers provided in the space downstream of the conveying direction of the glass plate, the ,
The said auxiliary | assistant roller is provided on the conveyance path between the said cooling roller pair, and the pair of the pulling-down roller located in the most upstream of the said conveyance direction among the pulling-down roller pairs. Method of manufacturing glass plate.   4. The pair of auxiliary rollers according to claim 1, wherein the distance between the pair of auxiliary rollers is gradually narrowed after the tip of the glass body passes between the pair of auxiliary rollers. The manufacturing method of the glass plate as described in-.   After the glass body is nipped by the transport roller pair, the distance between the pair of auxiliary rollers is increased to retract the pair of auxiliary rollers to a position not in contact with the glass body and the glass substrate. The manufacturing method of the glass plate of any one of Claims 1-4 which performs the said formation process and the said cooling process.   The method for manufacturing a glass sheet according to any one of claims 1 to 5, wherein a roller width of the auxiliary roller is wider than a product width of the glass sheet and narrower than a separation distance of the transport roller pair.

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