CN109574472B

CN109574472B - Glass substrate manufacturing method and glass substrate manufacturing device

Info

Publication number: CN109574472B
Application number: CN201811130784.4A
Authority: CN
Inventors: 菅原司人
Original assignee: Avanstrate Holding Co ltd; Avanstrate Inc
Current assignee: Avanstrate Holding Co ltd; Avanstrate Inc
Priority date: 2017-09-29
Filing date: 2018-09-27
Publication date: 2021-11-23
Anticipated expiration: 2038-09-27
Also published as: CN109574472A; KR20190038350A; KR102136931B1

Abstract

The invention aims to prevent damage of a temperature adjusting device caused by falling objects from a glass plate. The present invention relates to a glass substrate manufacturing method and a glass substrate manufacturing apparatus. The glass substrate manufacturing method includes a cooling step of cooling a glass plate by conveying the glass plate in a downward direction in a space surrounded by a furnace wall. A partition member is provided in the space, the partition member partitioning the space into a plurality of spaces and forming a slit through which the glass sheet passes. In the cooling step, the glass sheet is cooled using a temperature adjusting device for controlling the temperature of the glass sheet while the glass sheet is conveyed through the slit. The temperature adjusting device is arranged at a position opposite to the glass plate and controls the temperature of the spaced space so as to control the temperature of the glass plate along the width direction. The partition member has a distal end portion extending from above the temperature adjustment device toward the glass plate so as to face the glass plate and to be inclined downward with respect to the horizontal direction.

Description

Glass substrate manufacturing method and glass substrate manufacturing device

Technical Field

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

Background

A method of manufacturing a glass sheet (sheet glass) using a down-draw method is known. The sheet glass formed by the downdraw method has a central region in the width direction in which the sheet thickness is substantially constant, and end portions (lug portions) located outside the central region in the width direction and having a sheet thickness greater than that of the central region. The central area is the product area. In the downdraw method, in order to stably convey the formed sheet glass in the downward direction, a region (nip region) of the sheet glass located at the boundary between the central region and the end portion is nipped by conveying rollers.

The sheet glass is cooled (slowly cooled) so that the warpage and strain satisfy certain quality standards. Therefore, a temperature distribution (temperature profile) in the width direction is designed in advance along the flow direction of the sheet glass, and strict temperature control is performed using a cooling device, a temperature adjusting device (heater), or the like so as to realize the temperature profile in the sheet glass (patent document 1).

In order to control the temperature of the sheet glass, a partition member may be used to block heat transfer from an upper space to a lower space in the vicinity of the sheet glass. The partition member is provided, for example, one by one between a plurality of heaters arranged along the conveyance direction, and the heaters adjust the temperature of the sheet glass so as to realize a temperature profile in the facing sheet glass.

[ background Art document ]

[ patent document ]

[ patent document 1] Japanese patent laid-open publication No. 2013-212987

Disclosure of Invention

[ problems to be solved by the invention ]

Sheet glass may be cracked during conveyance. Further, a glass sheet or glass cullet may fall downward from the cracked sheet glass. Such a falling object from the sheet glass may collide with the partition member and bounce, and may contact the heater, or may directly collide with the heater to damage the heater. In addition, the falling object from the sheet glass may be accumulated on the upper surface of the partition member to shield the radiant heat from the temperature adjusting device toward the sheet glass.

Accordingly, an object of the present invention is to provide a glass substrate manufacturing method and a glass substrate manufacturing apparatus capable of preventing damage to a temperature adjustment device due to a falling object from a glass plate. More specifically, an object of the present invention is to provide a glass substrate manufacturing method and a glass substrate manufacturing apparatus capable of protecting a temperature adjustment device from a falling object while appropriately controlling the temperature by the temperature adjustment device, and preventing the falling object from accumulating on a partition member.

[ means for solving problems ]

One aspect of the present invention is a method for manufacturing a glass substrate, including:

a forming step of forming a glass sheet by forming molten glass by an overflow down-draw method; and

a cooling step of cooling the glass sheet by conveying the glass sheet downward while sandwiching both side regions in the width direction of the glass sheet between a plurality of conveying roller pairs provided along the conveying direction of the glass sheet in a space surrounded by a furnace wall;

providing a partition member that partitions the space into a plurality of spaces along the conveyance direction and forms a slit through which the glass sheet passes,

in the cooling step, the glass plate is cooled using a temperature adjusting device for controlling the temperature of the glass plate while the glass plate is conveyed through the slit,

the temperature adjusting device is disposed at a position facing the glass plate, controls the temperature of the spaced space to control the temperature of the glass plate in the width direction, and

the partition member has a tip end portion extending from above the temperature adjustment device toward the glass plate so as to face the glass plate and to be inclined downward with respect to a horizontal direction.

Preferably, a front end position of the front end portion is located within a height range in the conveying direction in which the temperature adjusting device is located.

Preferably, the partition member further includes a rear end portion connected to the front end portion and extending away from the glass plate, and the rear end portion partitions a space on an upstream side of the temperature adjusting device with respect to the conveying direction above the temperature adjusting device.

Preferably, the tip end portion extends in the width direction of the glass plate so as to face both side regions in the width direction of the glass plate and a region between the both side regions, and the tip end portion

The inclination angle of the tip end portion is smaller at a portion of the tip end portion facing the both side regions than at a portion of the tip end portion facing a region between the both side regions.

Preferably, when the temperature adjustment device is referred to as a 1 st temperature adjustment device, the partition member is referred to as a 1 st partition member, and the tip end portion is referred to as a 1 st tip end portion,

in the cooling step, the glass sheet is cooled so that the temperature of the glass sheet decreases in the conveyance direction using a temperature control device row that is provided along the conveyance direction of the glass sheet and includes at least the 1 st temperature control device and the 2 nd temperature control device disposed below the 1 st temperature control device,

the 2 nd temperature adjusting device is partitioned from a space on an upstream side with respect to the conveying direction by a 2 nd partition member extending at least between the 2 nd temperature adjusting device and the glass plate in a horizontal direction,

the 2 nd partition member has a 2 nd tip portion extending from above the 2 nd temperature adjustment device toward the glass plate so as to face the glass plate, the 2 nd tip portion being inclined with respect to the horizontal direction and facing the glass plate, and

the length of the 1 st tip in the extending direction is longer than the length of the 2 nd tip in the extending direction.

Preferably, the position of the center of the rotation axis of the roller of the conveying roller pair is located above or below a height range in which the temperature adjusting device is located in a direction along the conveying direction.

Preferably, at least some of the conveying roller pairs are arranged such that the center of the rotation axis is located between the temperature adjustment devices adjacent in the conveying direction, and the distance along the conveying direction between the roller of the conveying roller pair and the temperature adjustment device arranged above the roller and closest to the roller is smaller the conveying roller pair located on the downstream side in the conveying direction.

Another aspect of the present invention is a glass substrate manufacturing apparatus including a forming device for forming a glass sheet by forming a molten glass by an overflow down-draw method,

the forming device comprises:

a plurality of pairs of conveying rollers provided at intervals in a conveying direction of the glass sheet in a space surrounded by a furnace wall, and conveying the glass sheet in a downward direction while sandwiching both side regions in a width direction of the glass sheet;

a partition member that partitions the space into a plurality of spaces along the conveyance direction and forms a slit through which the glass sheet passes; and

a temperature adjusting device for controlling the temperature of the glass plate conveyed through the slit and cooling the glass plate; and is

The temperature adjusting device is arranged at a position opposite to the glass plate and controls the temperature of the spaced space so as to control the temperature of the glass plate along the width direction;

the partition member has a distal end portion extending from above the temperature adjustment device toward the glass plate so as to be inclined downward with respect to a horizontal direction so as to face the glass plate.

[ Effect of the invention ]

According to the present invention, damage to the temperature control device due to a falling object from the glass plate can be prevented.

Drawings

Fig. 1 is a flowchart of a glass plate manufacturing method according to the present embodiment.

FIG. 2 is a schematic view showing a glass plate manufacturing apparatus used in the glass plate manufacturing method.

Fig. 3 is a schematic view (sectional view) of the molding apparatus.

Fig. 4 is a schematic view (side view) of the forming apparatus.

Fig. 5 is a control block diagram of the control device.

Fig. 6 is an enlarged view of a part of fig. 3.

Fig. 7 is a diagram showing a modification of the partition member.

Fig. 8 is a diagram showing a modification of the partition member.

Fig. 9(a) and (b) are diagrams for explaining the operation of the modification of fig. 8.

Detailed Description

By the glass substrate manufacturing method of the present embodiment, for example, a glass substrate for a TFT (Thin Film Transistor) display is manufactured. Glass sheets are manufactured using an overflow downdraw process. Hereinafter, the method for manufacturing a glass substrate according to the present embodiment will be described with reference to the drawings.

(1) Outline of glass substrate manufacturing method

First, a plurality of steps included in the glass substrate manufacturing method and a glass substrate manufacturing apparatus 100 used for the plurality of steps will be described with reference to fig. 1 and 2. As shown in fig. 1, the glass substrate manufacturing method mainly includes a melting step S1, a fining step S2, a forming step S3, a cooling step S4, and a cutting step S5.

The melting step S1 is a step of melting the glass raw material. The glass raw material is prepared so as to have a desired composition, and then is charged into a melting apparatus 11 disposed upstream. The glass raw material is composed of, for example, SiO2, Al2O3, B2O3, CaO, SrO, BaO, and the like. Specifically, a glass material having a strain point of 660 ℃ or higher is used. The glass raw material is melted in the melting device 11 to become molten glass FG (see fig. 3 and 4). The melting temperature is adjusted according to the kind of glass. In this embodiment, the glass raw material is melted at 1500 to 1650 ℃. Molten glass FG is delivered to fining device 12 through upstream conduit 23.

The fining step S2 is a step of removing bubbles in the molten glass FG. The bubbled molten glass FG within fining device 12 is then conveyed through downstream conduit 24 to forming device 40.

The forming step S3 is a step of forming the molten glass FG into a sheet-like glass (sheet glass) SG. Specifically, after the molten glass FG is continuously supplied to the forming body 41 (see fig. 3 and 4) included in the forming apparatus 40, the molten glass FG overflows from the forming body 41. The overflowing molten glass FG flows down along the surface of the forming body 41. Then, the molten glass FG merges at the lower end portion 41a (see fig. 3 and 4) of the forming body 41 and is formed into the sheet glass SG. The sheet glass SG has side portions (ear portions, end portions) located at ends in the width direction, and a central region in the width direction sandwiched between the side portions. The thickness of the side portions of the sheet glass SG is formed to be thicker than the thickness of the central region. The central region of the sheet glass SG is a region of a product to be a glass substrate having a fixed thickness. The sheet glass SG has a central region formed into a thin sheet having a thickness of, for example, 0.4mm or less. The width direction of the sheet glass SG is a direction orthogonal to the direction in which the sheet glass SG flows downward (the flow direction, the conveyance direction) and the thickness direction of the sheet glass SG.

The cooling step S4 is a step of conveying and cooling (slow cooling) the sheet glass SG downward while sandwiching both side regions in the width direction of the sheet glass SG between pull-down rollers described below provided along the conveying direction of the sheet glass SG in a space surrounded by a furnace wall (not shown). The region sandwiched by the pull-down roller is a sandwiched region located at the boundary between the central region and the side portion. The sheet glass SG is cooled to a temperature close to room temperature through the cooling step S4. The thickness (plate thickness) of the glass substrate, the amount of warp of the glass substrate, and the amount of strain of the glass substrate are determined in accordance with the cooling state in the cooling step S4.

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

The sheet glass SG cut into a predetermined size is subjected to a step of edge finishing or the like to be a glass substrate.

Next, the structure of the molding device 40 included in the glass substrate manufacturing apparatus 100 will be described with reference to fig. 3 to 5.

(2) Constitution of forming apparatus

Fig. 3 and 4 show a schematic configuration of the molding device 40. Fig. 3 is a sectional view of the forming device 40. Fig. 4 is a side view of the forming device 40.

The forming device 40 has a passage through which the sheet glass SG passes and a space surrounding the passage. The space surrounding the passage is a space surrounded by the furnace wall, and includes the overflow chamber 20, the formation chamber 30, and the 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. The molten glass FG flows down along the surface of the molded body 41, merges at the lower end portion 41a of the molded body 41, and is molded into the sheet glass SG.

The forming chamber 30 is a space disposed below the overflow chamber 20 for adjusting the thickness and the amount of warp of the sheet glass SG. In the forming chamber 30, a part of the cooling step ST4 is performed. The temperature of the sheet glass SG gradually decreases further downstream than the lower end portion 41a of the forming body 41.

The cooling chamber 80 is a space disposed below the overflow chamber 20 and used for adjusting the amount of strain of the sheet glass SG. Specifically, in the cooling chamber 80, the sheet glass SG having passed through the forming chamber 30 passes through the slow cooling point and the strain point and is cooled to a temperature near room temperature. The inside of the cooling chamber 80 is divided (partitioned) into a plurality of spaces by a plurality of partition members 83 arranged at intervals in the conveyance direction of the sheet glass SG. Details of the partition member 83 will be described later.

The molding device 40 mainly includes a molded body 41, a heat insulating member 50, a cooling roller 51, a cooling unit 60, pull-down rollers (conveying rollers) 81a to 81g, heaters (temperature adjusting devices) 82a to 82g, a partition member 83, and a cutting device 90. Further, the molding device 40 includes a control device 500 (see fig. 5). The control device 500 controls the driving units of the respective configurations included in the molding device 40.

Hereinafter, each configuration included in the molding device 40 will be described in detail.

(2-1) molded article

The forming body 41 is disposed in the overflow chamber 20. The forming body 41 forms the molten glass FG into the sheet glass SG by overflowing the molten glass FG.

As shown in fig. 3, the formed body 41 has a shape (a shape similar to a wedge) whose sectional shape is substantially pentagonal. The front end of the substantially pentagonal shape corresponds to the lower end portion 41a of the molded body 41.

The molded body 41 has an inlet 42 at the 1 st end (see fig. 4). The inflow port 42 is connected to the downstream pipe 24, and the molten glass FG flowing out of the fining device 12 flows into the forming body 41 through the inflow port 42. The molded body 41 has a groove 43 formed therein. The groove 43 extends in the longitudinal direction (the left-right direction in fig. 4) of the molded body 41. Specifically, the groove 43 extends from the 1 st end to the 2 nd end opposite to the 1 st end. The groove 43 is formed deepest in the vicinity of the inflow port 42 and becomes gradually shallower as it approaches the No. 2 end. The molten glass FG that has flowed into the forming body 41 overflows from the pair of

top portions

41b, 41b of the forming body 41 and flows down along the pair of side surfaces (surfaces) 41c, 41c of the forming body 41. Then, the molten glass FG merges at the lower end portion 41a of the formed body 41 to become sheet glass SG.

At this time, the sheet glass SG at the lower end portion 41a of the forming body 41 has a liquidus temperature of 1100 ℃ or higher and a liquidus viscosity of 2.5 × 105 poises or higher, and more preferably, the liquidus temperature is 1160 ℃ or higher and the liquidus viscosity is 1.2 × 105 poises or higher. In addition, the viscosity of the side portions (ears, ends) of the sheet glass SG at the lower end portion 41a of the formed body 41 is less than 105.7 poise.

(2-2) Heat insulating Member

The heat insulating member 50 blocks heat transfer from the overflow chamber 20 to the formation chamber 30. The heat insulating member 50 is disposed in the vicinity of the confluence point of the molten glass FG. As shown in fig. 3, the heat insulating members 50 are disposed on both sides in the thickness direction of the molten glass FG (sheet glass SG) merged at the merging point. The heat insulating member 50 blocks heat transfer from the upper side to the lower side of the heat insulating member 50 by separating the upper side environment and the lower side environment of the confluence point of the molten glass FG.

(2-3) Cooling roll

The cooling roller 51 is disposed in the forming chamber 30. More specifically, the cooling roller 51 is disposed directly below the heat insulating member 50. The cooling rollers 51 are disposed on both sides of the sheet glass SG in the thickness direction and both sides of the sheet glass SG in the width direction. The cooling rollers 51 disposed on both sides in the thickness direction of the sheet glass SG operate in pairs. That is, the nip area in both side areas of the sheet glass SG is nipped by the two pairs of cooling rollers 51, ….

The cooling roller 51 is air-cooled by an air-cooling pipe penetrating therethrough. The cooling roller 51 is in contact with the side portions (ears, end portions) R, L of the sheet glass SG, and rapidly cools the side portions (ears, end portions) R, L of the sheet glass SG by heat conduction (rapid cooling step). The viscosity of the side portion R, L of the sheet glass SG contacting the cooling roller 51 is a predetermined value (specifically, 109.0 poise) or more.

The cooling roller 51 is rotationally driven by a cooling roller drive motor 390 (see fig. 5). The cooling roller 51 cools the side portion R, L of the sheet glass SG and also has a function of pulling down the sheet glass SG.

(2-4) Cooling Unit

The cooling unit 60 is provided in the overflow chamber 20 and the forming chamber 30, and cools the sheet glass SG to the vicinity of the slow cooling point. The cooling unit 60 has a plurality of cooling elements 61-65. In fig. 4, the cooling unit 60 is shown only within the forming chamber 30. The plurality of cooling elements 61-65 are arranged along the width direction of the sheet glass SG and the flow direction of the sheet glass SG. Specifically, the plurality of cooling elements 61 to 65 include central region cooling elements 61 to 63 and

side cooling elements

64 and 65.

The central area cooling elements 61 to 63 are air-cooled to cool the central area CA of the sheet glass SG. Here, the central region of the sheet glass SG means 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 region located between both side portions (both ear portions, both end portions) of the sheet glass SG. The central area cooling elements 61 to 63 are arranged at positions facing the surface of the central area CA of the sheet glass SG in the flow direction. Each unit included in the central area cooling elements 61-63 can be independently controlled.

The

side cooling elements

64 and 65 are water-cooled to cool the side portions (ear portions and end portions) R, L of the sheet glass SG. The

side cooling elements

64 and 65 are disposed at positions facing the surfaces of the side portions R, L (both end portions in the width direction) of the sheet glass SG in the flow direction. The units contained in the

side cooling elements

64, 65 can be controlled independently.

(2-5) Pull roll

The down-drawing rollers 81a to 81g are provided in the cooling chamber 80, and pull down the sheet glass SG that has passed through the forming chamber 30 in the flow direction of the sheet glass SG, thereby conveying the sheet glass SG. The pull-down rollers 81a to 81g are disposed inside the cooling chamber 80 at intervals in the flow direction. In the example shown in fig. 3 and 4, the pull-down rollers 81a to 81g are disposed in each space partitioned by the partition member 83. The pull-down rollers 81a to 81g are disposed in a region in the cooling chamber 80 where the temperature of the sheet glass SG becomes the slow cooling point or less. The region where the temperature of the sheet glass SG becomes equal to or lower than the slow cooling point is a region where the temperature of the central region of the sheet glass SG becomes equal to or lower than the slow cooling point, and is a region where the sheet glass SG is cooled to a temperature near room temperature through the slow cooling point and the strain point. The slow cooling point is the temperature at which the viscosity becomes 1013 poise, here 715.0 ℃. In the example shown in fig. 3 and 4, the position where the temperature of the sheet glass SG becomes the slow cooling point is between the partition member 83 located on the most upstream side in the conveyance direction and the pull-down roller 81a in the conveyance direction.

The pull-down rollers 81a to 81g are disposed on both sides of the sheet glass SG in the thickness direction (see fig. 3) and on both sides of the sheet glass SG in the width direction (see fig. 4), respectively. Thus, the down-draw rollers 81a to 81g pull down the sheet glass SG while contacting the surfaces on both sides (both ear portions and both end portions) R, L in the thickness direction of the sheet glass SG in the width direction of the sheet glass SG. The pull-down rollers 81a to 81g disposed on both sides in the thickness direction of the sheet glass SG operate in pairs, and the pair of pull-down rollers (conveying roller pair) 81a, … pull down the sheet glass SG in the downward direction.

The pull-down rollers 81a to 81g are driven by a pull-down roller drive motor 391 (see fig. 5). Further, the pull-down rollers 81a to 81g rotate in the direction in which the upstream portion approaches the sheet glass SG. The peripheral speeds of the pull-down rollers 81a to 81g are set to be larger as the pull-down rollers are located more downstream. That is, of the plurality of pull-down rollers 81a to 81g, the peripheral speed of the pull-down roller 81a is the smallest, and the peripheral speed of the pull-down roller 81g is the largest.

(2-6) Heater (temperature adjusting device)

The heaters 82(82a to 82g) are provided inside the cooling chamber 80, and adjust the temperature of the internal space of the cooling chamber 80. Specifically, the plurality of heaters 82a to 82g are arranged in the flow direction of the sheet glass SG and the width direction of the sheet glass SG. In the example shown in fig. 3 and 4, 7 heaters 82a to 82g are arranged in the flow direction of the sheet glass SG with an interval therebetween, and are arranged in each space partitioned (spaced) by the partition member 83. The heaters disposed in the respective spaces are configured by, for example, 7 heater elements (not shown) arranged in a direction along the width direction of the sheet glass. The heaters disposed in the respective spaces control the temperatures of the partitioned spaces to control the temperature of the sheet glass SG in the width direction. The heater element is made of, for example, a metal member having good heat conduction such as pure nickel, or a ceramic material. The heater elements are disposed at positions facing both side regions of the sheet glass SG and a region between both side regions.

The heater 82 is disposed farther from the sheet glass SG than the pull-down rollers 81a to 81 g.

The heaters 82a to 82g are controlled and outputted by the control device 500 described below. In this way, the temperature of the sheet glass SG is controlled by controlling the ambient temperature in the vicinity of the sheet glass SG in the cooling chamber 80. Thereby, the sheet glass SG is cooled so that the temperature of the sheet glass SG decreases in the conveying direction. By this temperature control, the sheet glass SG is moved from the viscous region through the viscoelastic region to the elastic region. In the cooling chamber 80, the temperature of the sheet glass SG is cooled from the temperature near the slow cooling point to the temperature near the room temperature by the control of the heaters 82a to 82 g.

The heater elements are independently controlled by the control device 500 to adjust the ambient temperature in the vicinity of the sheet glass SG in such a manner that a previously designed temperature profile is achieved in the sheet glass SG. Specifically, the temperature profile is designed in such a manner that the temperature of the sheet glass SG becomes uniform in the width direction. Here, the temperature uniformity means that the temperature at which the temperature distribution in the width direction of at least the clamping region and the central region is formed is within ± 20 ℃ with respect to the average temperature of the clamping region and the central region. By cooling the sheet glass SG so that the temperature of the sheet glass SG becomes uniform in the width direction, the occurrence of strain in the nip region of the sheet glass SG and the region adjacent to the nip region can be suppressed.

A thermocouple 380, for example, is provided as a means for detecting the ambient temperature in the vicinity of each of the heaters 82a to 82 g. Specifically, the thermocouples 380 are disposed at intervals in the flow direction of the sheet glass SG and the width direction of the sheet glass SG. The thermocouple 380 detects the temperature of the center portion C of the sheet glass SG and the temperature of the side portion R, L of the sheet glass SG, respectively. The outputs of the heaters 82a to 82g are controlled based on the ambient temperature detected by the thermocouple 380.

(2-7) partition Member

The partition member 83 is a plate-shaped heat insulating member. The partition member 83 partitions the cooling chamber 80 into a plurality of spaces along the conveyance direction of the sheet glass SG, and forms a slit S through which the sheet glass SG passes. In the example shown in fig. 3, the slits S are gaps which are arranged on both sides of the sheet glass SG in the plate thickness direction and are formed between two partition members 83 facing each other. The slit S extends in the width direction of the sheet glass SG. The partition member 83 extends at least between the heater 82 and the sheet glass SG in the horizontal direction, and blocks heat transfer from the space above the partition member 83 to the space below at least between the heater 82 and the sheet glass SG. Since the heat transfer from the upper space to the lower space is particularly large around the sheet glass SG, the temperature control of the sheet glass SG based on the temperature curve can be appropriately performed.

The partition member 83 has a front end portion 83a, and the front end portion 83a extends from above the heater 82 toward the sheet glass SG obliquely with respect to the horizontal direction so that an upper surface thereof faces the sheet glass SG. The sheet glass SG may crack during conveyance, and glass pieces or glass chips may fall off from the sheet glass SG. The crack of the sheet glass SG may occur, for example, because the sheet glass SG is deformed in a flexible manner due to a change in the air flow rising along both side surfaces of the sheet glass SG or the like, and the crack may be deepened by the contact with the partition member 83. Further, for example, the pull-down rollers 81a to 81g may be worn to change the position where the sheet glass SG is nipped. In the present embodiment, the leading end portion 83a of the partition member 83 extends downward from above the heater 82 toward the sheet glass SG, and is disposed so as to shield the heater 82 from falling objects, so that falling objects such as glass sheets can be prevented from directly colliding with the heater 82 or bouncing up by colliding with the leading end portion 83a to come into contact with the heater 82. Therefore, damage to the heater 82 can be prevented.

Further, since the upper surface of the front end portion 83a is inclined with respect to the horizontal direction so as to face the sheet glass SG, the falling objects falling onto the front end portion 83a can slide down along the upper surface of the front end portion 83 a. Therefore, the falling objects can be prevented from remaining and accumulating at the front end portion 83 a. This can prevent, for example, the radiant heat from the heater 82 from being blocked by the deposited falling object and the temperature of the sheet glass SG from being controlled appropriately.

That is, according to the present embodiment, by the partition function of the partition member 83, temperature control by the heater 82 can be appropriately performed, and when a crack is generated in the sheet glass SG, the heater 82 can be protected from a falling object and the falling object is prevented from being accumulated on the partition member 83.

The inclination angle of the front end portion 83a is preferably 20 to 50 °, for example, 30 to 40 °, with respect to the horizontal direction toward the side of the upper surface of the front end portion 83a facing the sheet glass SG. If the inclination angle is less than 20 °, the dropped object may be difficult to slide down and accumulate on the distal end portion 83 a. If the inclination angle exceeds 50 °, the radiant heat from the heater 82 may be shielded by the leading end portion 83a and the temperature of the sheet glass SG may not be appropriately controlled.

Further, the inclination angle of the distal end portion 83a along the thickness direction (the left-right direction in fig. 3) of the sheet glass SG is fixed in the example shown in fig. 3, but may be changed while extending toward the sheet glass SG, and for example, the distal end portion 83a may be bent or bent when viewed from a direction orthogonal to the extending direction (the direction from the side away from the sheet glass SG toward the side close to the sheet glass SG) and the thickness direction of the distal end portion 83 a.

Fig. 6 is an enlarged view of a part of the molding apparatus of fig. 3. As shown in fig. 6, the length L1 in the extending direction of the leading end portion 83a is preferably greater than 50% of the interval L2 between the heater 82 and the sheet glass SG in the horizontal direction. If the length L1 in the extending direction of the leading end portion 83a is 50% or less of the horizontal direction interval L2 between the heater 82 and the sheet glass SG, there are cases where: the heater 82 cannot be sufficiently protected from the falling object, and the heat transfer cannot be sufficiently blocked by the partition member 83, and the partition function is lowered.

On the other hand, the length L1 of the leading end portion 83a is preferably smaller than the interval L3, and the interval L3 is an interval between the upper end of the ends of the heaters 82 facing the sheet glass SG and the pull-down roller positioned closest to the heater 82 (for example, the pull-down roller 81e positioned closest to the lower side of the upper end of the heater 82 e) among the pull-down rollers positioned below the upper end. Since the leading end portion 83a reflects the radiant heat from the sheet glass SG, if the length L1 of the leading end portion 83a is equal to or greater than the interval L3, the pull-down roller disposed above the leading end portion 83a and closest to the leading end portion 83a (for example, the pull-down roller 81e disposed above the leading end portion 83a of the lower partition member 83 and closest to the leading end portion 83a in the two partition members 83 shown in fig. 6) may be heated and damaged.

In each partition member 83, the position (front end position) of the end of the front end portion 83a disposed closest to the sheet glass SG is preferably located within the range (height range) in the conveyance direction in which the heater 82 is located, as shown in fig. 6. In other words, the front end of the front end portion 83a is preferably located in front of the heater 82 (on the side facing the sheet glass SG in the horizontal direction from the heater 82). By positioning the front end portion of the front end portion 83a in front of the heater 82 in this manner, the function of protecting the heater 82 from falling objects is enhanced.

The partition member 83 preferably further has a rear end portion 83b, as in the example shown in fig. 3, and the rear end portion 83b is connected to the front end portion 83a and extends away from the sheet glass SG. The rear end portion 83b has a function of partitioning a space on the upstream side of the heater 82 with respect to the conveyance direction above the heater 82. By the partition member 83 having the rear end portion 83b, the partition function is enhanced.

In the example shown in fig. 3, the rear end portion 83b extends in the horizontal direction, but may be inclined with respect to the horizontal direction so that the upper surface of the rear end portion 83b faces the sheet glass SG. In this case, the inclination angles of the front end portion 83a and the rear end portion 83b may be equal (see fig. 8). In addition, the partition member 83 may not have a rear end portion.

In the example shown in fig. 4, the leading end portion 83a extends in the width direction of the sheet glass SG so as to face both side regions and a region (central region) between both side regions in the width direction of the sheet glass SG. In this case, the inclination angle of the distal end portion 83a is preferably smaller in the portion facing the both side regions than in the portion facing the central region. The reason is that if glass chips or the like falling on the portions of the leading end portion 83a facing the both side regions of the sheet glass SG slip off, the glass chips or the like may adhere to the surfaces of the lower draw rollers 81a to 81g, and scratch the sheet glass SG, which may become the starting point of the crack.

For the same reason, the length of the distal end portion 83a in the extending direction is preferably shorter in the portions of the distal end portion 83a facing the both side regions in the width direction of the sheet glass SG than in the portions of the distal end portion 83a facing the central region.

Fig. 7 and 8 show a modification of the partition member.

Fig. 7 is a diagram showing a modification of the partition member 83. Fig. 8 is a diagram showing another modification of the partition member 83.

The partition member 83 may be configured such that the front end portion 83a is rotated with respect to the rear end portion 83b, as in the modification shown in fig. 7. In this modification, the front end 83a is connected to the rear end 83b by a hinge and can be rotated as shown by the broken line in fig. 7. In the modification shown in fig. 7, only the tip end portion 83a is inclined with respect to the horizontal direction, and therefore, the inclination angle with respect to the horizontal direction is easily increased as compared with the case where the entire partition member 83 is rotated and inclined.

The partition member 83 may be configured so that the entire member is rotated with respect to the furnace wall, as in the modification shown in fig. 8. The furnace wall is a structure that surrounds the overflow chamber 20, the forming chamber 30, and the cooling chamber 80 and is made of a heat insulating member. The modification shown in fig. 8 is an example in which the inclination angles of the front end portion 83a and the rear end portion 83b are equal. In this modification, the partition member 83 is configured such that the end (rear end) of the rear end portion 83b farthest from the sheet glass SG rotates around a rotation shaft provided in the furnace wall. The partition member 83 may be screwed as shown by a dotted line in fig. 8.

If the front end portion 83a is located in front of the heater 82, the radiation of heat from the heater 82 is shielded according to its inclination angle. In the modification described above, the partition member 83 is used, and the tip portion 83a or the entire partition member 83 is rotated in operation, and the tip portion 83a is rotated so that the upper surface thereof extends in the horizontal direction or the inclination angle with respect to the horizontal direction becomes smaller. Thereby, the temperature of the sheet glass SG can be adjusted by adjusting the amount of heat emitted from the heater 82.

In addition, in the case where a glass sheet or the like that is broken and dropped by the sheet glass SG exists on the distal end portion 83a, for example, the partition member 83 of the above-described modification can be used, and in operation, from the state shown by the solid line in fig. 7 and 8, the entire distal end portion 83a or the partition member 83 is turned to increase the inclination angle. This allows the glass sheet or the like present on the distal end portion 83a to slide and fall downward. Such a change in the tilt angle can be manually or automatically performed by, for example, applying a mechanical force generated by a spring or a cylinder to the distal end portion 83a or the partition member 83.

Fig. 9(a) and 9(b) are views for explaining an example in which a driving device 70 having a cylinder 71 is used to rotate the partition member 83 shown in fig. 8 according to a variation. Specifically, the driving device 70 includes a cylinder 71 and a shaft 72 reciprocating with respect to the cylinder 71. The cylinder 71 is provided so as to be rotatable with respect to the furnace wall. The shaft 72 is connected to the partition member 83. In this modification, the inclination angle of the partition member 83 changes as the shaft 72 moves relative to the cylinder 71. For example, the partition member 83 is rotated between a state of extending in the horizontal direction shown in fig. 9(a) and a state of being inclined with respect to the horizontal direction shown in fig. 9 (b).

The operation mode for rotating the tip portion 83a or the partition member 83 is not limited to the example shown in fig. 9, and is appropriately selected depending on the structure in the furnace or the temperature in the furnace in which the partition member 83 is provided. The above-described modification of the partition member 83 can be suitably employed for the purpose of removing a glass sheet or the like.

According to one embodiment, it is preferable that the length of the front end portion 83a (1 st front end portion) of the upstream-side partition member 83 in the extending direction is longer than the length of the front end portion 83a (2 nd front end portion) of the downstream-side partition member 83 in the extending direction, among the plurality of partition members 83. Since the amount of heat of radiation from the heater 82 is larger as the heater 82 is located more upstream, it is preferable to increase the length of the 1 st leading end portion 83a in the extending direction to improve the partitioning function of the partitioning member 83. In this case, the length of the partition member 83 in the extending direction is preferably shortened continuously or stepwise from the upstream side to the downstream side.

In addition, according to one embodiment, it is preferable that, among the plurality of partition members 83, the inclination angle with respect to the horizontal direction of the front end portion 83a (1 st front end portion) of the upstream-side partition member 83 is smaller than the inclination angle with respect to the horizontal direction of the front end portion 83a (2 nd front end portion) of the downstream-side partition member 83. As described above, since the amount of heat of the radiant heat from the heater 82 is larger as the heater 82 is located more upstream, it is preferable to reduce the inclination angle of the 1 st tip portion 83a so as to reduce the influence on the temperature adjustment of the sheet glass SG caused by shielding the radiant heat from the heater 82. In this case, the inclination angle of the partition member 83 is preferably increased continuously or stepwise from the upstream side to the downstream side.

The rotation axis centers O of the pull-down rollers 81a to 81g are preferably positioned above or below a height range H (see fig. 6) in which the heater 82 is positioned in the direction along the conveying direction, as shown in fig. 3. For example, the position of the rotation axis center O of the pull-down roller 81a is located below the lower end of the heater 82a and above the upper end of the heater 82 b. Thus, the positions of the rotation axis centers O of the pull-down rollers 81a to 81g and the height range H in which the heater 82 is located do not overlap (deviate) in the conveying direction, so that the radiant heat from the heater 82 is less likely to be shielded by the pull-down rollers 81a to 81g, and a decrease in temperature in both side regions of the sheet glass SG can be suppressed. Therefore, a uniform temperature distribution in the width direction in the sheet glass SG can be effectively achieved.

In this case, it is preferable that the position of the rotation axis center O of the pull-down rollers 81a to 81f is longer than the interval between the heater 82 disposed near the upper side and the heater 82 disposed near the lower side, out of the two heaters 82 disposed near the upper and lower sides in the conveying direction. Since the sheet glass SG is cooled so that the temperature thereof decreases in the conveyance direction, the radiant heat is controlled to increase as the heater 82 located on the upstream side is located. Since the pull-down rollers 81a to 81f and the lower heater 82 are partitioned by the partition member 83, even if the distances between the pull-down rollers 81a to 81f and the lower heater 82 are shorter than the distances between the pull-down rollers 81a to 81f and the upper heater 82, the amount of heat received by the pull-down rollers 81a to 81f from the heater 82 can be suppressed. This can prevent the pull-down rollers 81a to 81f from being overheated by the heater 82.

(2-8) cutting device

The cutting device 90 cuts the sheet glass SG cooled to a temperature near the 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 cutter 90 is driven by a cutter drive motor 392 (see fig. 5).

(2-9) control device

The control device 500 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a hard disk, and the like, and controls various devices included in the glass substrate manufacturing apparatus 100. Fig. 5 is a block diagram showing an example of the configuration of the control device 500 according to the embodiment.

Specifically, as shown in fig. 5, the control device 500 receives signals from various sensors (e.g., the thermocouple 380) and switches (e.g., the main power switch 381) included in the glass substrate manufacturing apparatus 100, and controls the cooling unit 60, the heaters 82a to 82g, the cooling roller drive motor 390, the pull-down roller drive motor 391, the shutoff device drive motor 392, and the like.

According to the present embodiment, temperature control by the heater 82 can be appropriately performed by the partition function of the partition member 83, and when a crack occurs in the sheet glass SG, the heater 82 can be protected from a falling object, and the falling object is prevented from being accumulated on the partition member 83.

While the present embodiment has been described above with reference to the drawings, the specific configuration is not limited to the above embodiment, and may be modified within a range not departing from the spirit of the invention.

For example, the pull-down rollers 81a to 81g may be arranged at equal intervals in the conveyance direction, or may be arranged at different intervals in the conveyance direction. For example, the intervals between the pull-down rollers 81a to 81g adjacent to each other in the conveyance direction may be set to be larger toward the downstream side. The pull-down rollers 81a to 81g may not be disposed in each space partitioned by the partition member 83.

[ description of symbols ]

11: dissolving device

12: clarification device

40: forming device

41: formed body

51: cooling roller

60: cooling unit

81 a-81 g: pull-down roller

82 a-82 g: heater (temperature adjusting device)

83: partition member

83 a: front end part

83 b: rear end part

90: cutting device

100: glass substrate manufacturing device

500: control device

Claims

1. A method for manufacturing a glass substrate, comprising:

a cooling step of conveying the glass sheet downward while cooling both side regions in a width direction of the glass sheet by cooling roller pairs in a space surrounded by a furnace wall, and further conveying and cooling the glass sheet downward while clamping both side regions by a plurality of conveying roller pairs provided along a conveying direction of the glass sheet on a downstream side of the cooling roller pairs in the conveying direction of the glass sheet;

a partition member that partitions a space on a downstream side of the cooling roller pair in the conveyance direction among the spaces into a plurality of spaces in the conveyance direction and forms a slit through which the glass sheet passes is provided in the space,

2. The glass substrate manufacturing method according to claim 1, wherein the partition member further has a rear end portion that is connected to the front end portion and extends away from the glass plate, and that partitions a space on an upstream side of the temperature adjustment device with respect to the conveyance direction above the temperature adjustment device.

3. The glass substrate manufacturing method according to claim 1 or 2, wherein the tip portion extends in the width direction of the glass plate so as to face both side regions in the width direction of the glass plate and a region between the side regions, and the tip portion is configured to face a region between the side regions

4. The glass substrate manufacturing method according to claim 1 or 2, wherein when the temperature adjustment device is referred to as a 1 st temperature adjustment device, the partition member is referred to as a 1 st partition member, and the leading end portion is referred to as a 1 st leading end portion,

5. The glass substrate manufacturing method according to claim 1 or 2, wherein a position of a center of a rotation axis of a roller of the conveying roller pair is located above or below a height range in which the temperature adjusting device is located in a direction along the conveying direction.

6. The glass substrate manufacturing method according to claim 5, wherein at least some of the conveying roller pairs are arranged such that a center of a rotation axis is positioned between the temperature adjustment devices adjacent in the conveying direction, and a distance along the conveying direction between a roller of the conveying roller pair and a temperature adjustment device arranged above the roller and closest to the roller is smaller the conveying roller pair positioned on a downstream side in the conveying direction.

7. A glass substrate manufacturing apparatus is characterized by comprising a forming device for forming a glass plate by forming a molten glass by an overflow down-draw method,

the forming device comprises:

a pair of cooling rollers that convey the glass sheet downward while cooling the glass sheet by sandwiching and cooling both side regions in the width direction of the glass sheet in a space surrounded by a furnace wall;

a plurality of conveying roller pairs that are provided at intervals in the conveying direction of the glass sheet on a downstream side in the conveying direction of the glass sheet than the cooling roller pairs in a space surrounded by the furnace wall, and that convey the glass sheet in a downward direction while sandwiching both side regions in the width direction of the glass sheet;

a partition member that partitions a space on a downstream side in the conveyance direction from the pair of cooling rollers into a plurality of spaces in the conveyance direction and forms a slit through which the glass sheet passes; and