KR20140042679A - Glass substrate manufacturing method and a cooler - Google Patents

Abstract

The present invention relates to a method for producing a glass substrate. In a space in which a molded glass sheet is cooled, an effective and excellently controllable heat exchange can be performed on the glass sheet. Cooling speed controlling members (41a to 41f) are installed in at least some parts of a space in which a glass sheet (90) separated from a molded body (10) is cooled near a slow cooling point. The cooling speed controlling members are inserted in a rear cooling space (422) disposed at the opposite side of the glass sheet (90) so as to be installed as cooling chambers (422a to 422f) disposed along the moving direction of the glass sheet (90). The cooling chambers (422a to 422f) are cooled by coolers (51a to 51f). The cooler (51b) has a heat-insulating plate (52b) and a coolant pipe (53b). The heat-insulating plate (52b) controls the heat movement between the cooling chamber (422b) and a space adjacent to the cooling chamber (422b) along the moving direction thereof. A liquid coolant flows in the coolant pipe (53b) so as to cool the cooling chambers. [Reference numerals] (AA) Outlet; (BB) Inflow

Description

Glass substrate manufacturing method and cooler {GLASS SUBSTRATE MANUFACTURING METHOD AND A COOLER}

The present invention relates to a method for producing a glass substrate and a cooler.

Conventionally, the overflow down draw method is used as a method of manufacturing a glass substrate. In the overflow downdraw method, the molten glass which overflowed from the molded object flows down along both sides of the molded object, and then the glass sheet is molded by joining in the vicinity of the lower end of the molded body. The molded glass sheet is cooled while extending downward. The cooled glass sheet is cut into predetermined dimensions to obtain a glass substrate.

In the overflow downdraw method, the technique for controlling the cooling rate of a glass sheet at the time of cooling the molded glass sheet is used. For example, in patent document 1 (international publication 2012/018072 pamphlet), in the space below the molded object, the some cooling rate control member is arrange | positioned along the advancing direction of a glass sheet, and is attached to each of the cooling rate control members. A method of controlling the temperature of a glass sheet by injecting a gas of a predetermined temperature is disclosed. In addition, Patent Document 2 (Japanese Patent Laid-Open Publication No. 2009-502706) discloses a method of rapidly cooling a glass sheet immediately after being spaced apart from a lower end portion of a molded body so that the molded glass sheet reaches the final thickness more quickly. Is disclosed.

International Publication No. 2012/018072 Pamphlet Japanese Patent Publication No. 2009-502706

However, in the case of rapidly cooling the glass sheet immediately after being separated from the lower end of the molded body, in the method of using the cooling rate control member disclosed in Patent Document 1, the ability to cool the glass sheet is insufficient. Moreover, in this method, the temperature difference of a glass sheet arises because of the slight flow volume difference in the glass sheet width direction of the gas injected to a cooling rate control member. Moreover, in this method, the temperature difference of a glass sheet arises because a part of the gas injected to a cooling rate control member leaks unintentionally and collides with a glass sheet. And there exists a possibility that the plate | board thickness deviation of a glass sheet may increase by the temperature difference of a glass sheet.

An object of the present invention is to efficiently heat exchange with a heat source in a space where a molded glass sheet is cooled, and in which a heat source and a method for producing a glass substrate capable of performing heat exchange with the glass sheet efficiently and with excellent controllability exist. It is to provide a cooler capable of doing this.

The manufacturing method of the glass substrate which concerns on this invention is equipped with a shaping | molding process, a cooling process, and a cutting process. A molding process overflows a molten glass from a molded object, and shape | molds a glass sheet. The cooling step cools the molded glass sheet while extending downward. The cutting step cuts the cooled glass sheet to obtain a glass substrate. The cooling rate control member is provided in at least a part of the space to be cooled until the glass sheet spaced apart from the molded body is near the slow cooling point. The cooling rate control member opposes the surface of the center region in the width direction of the glass sheet. The rear cooling space on the opposite side of the glass sheet with the cooling rate control member interposed therebetween comprises a cooling chamber arranged along the advancing direction of the glass sheet. At least part of the cooling chamber is cooled by the cooler. In the cooling process, the glass sheet is cooled stepwise or continuously by moving along the advancing direction while facing the cooling rate control member in contact with the cooling chamber. At least part of the cooler has a heat insulating plate and a refrigerant pipe. The heat insulation board suppresses heat movement between the cooling chamber and the space adjacent to the cooling chamber along the traveling direction. The coolant pipe cools the cooling chamber by the flow of the liquid coolant therein.

In the manufacturing method of this glass substrate, the glass sheet immediately after separating from the lower end part of a molded object is quenched by the cooler to the vicinity of a slow cooling point. The cooler is composed of a heat insulating plate and a refrigerant pipe. The heat insulating plate is a partition wall for partitioning the rear cooling space into a plurality of cooling chambers along the advancing direction of the glass sheet, that is, the vertical direction. The refrigerant pipe performs efficient heat exchange by radiant heat transfer and natural convective heat transfer between the liquid refrigerant flowing therein and one of two spaces spaced by the heat insulating plate. The cooler can control the amount of heat exchange by adjusting the flow rate of the liquid refrigerant inside the refrigerant pipe or by changing the temperature of the liquid refrigerant. In addition, when the cooling rate adjustable range is further expanded, it is necessary to change the surface area of the refrigerant pipe by changing the number of round trips of the refrigerant pipe, or to change the temperature of the liquid refrigerant supplied to the refrigerant pipe.

Therefore, the manufacturing method of this glass substrate can perform heat exchange with a glass sheet efficiently and excellent in controllability in the space where the molded glass sheet is cooled.

In addition, it is preferable that a cooling process has a 1st cooling process and a 2nd cooling process. In a 1st cooling process, a glass sheet is cooled by a 1st average cooling rate until the temperature of the center area | region of a glass sheet becomes a slow cooling point. In a 2nd cooling process, a glass sheet is cooled by a 2nd average cooling rate until the temperature of the center area | region of a glass sheet becomes 50 degreeC lower than a strain point from a slow cooling point. It is preferable that a 1st average cooling rate is larger than a 2nd average cooling rate.

In a 1st cooling process, the temperature of the center area | region of a glass sheet is 1200 degreeC-slow cooling point, and the influence of thermal contraction rate is small. In this temperature region, the glass molecules easily move, and therefore deformation hardly occurs. On the other hand, in a 2nd cooling process, since the temperature of the center area | region of a glass sheet is a slow cooling point or strain point vicinity, and the influence of a thermal contraction rate is large, it is preferable to cool as slowly as possible. In this temperature region, compared with the first cooling step, the time required for the movement of the glass molecules is long, and deformation easily occurs. Therefore, it is preferable that a 1st average cooling rate is larger than a 2nd average cooling rate.

In the cooling step, the cooling rate of the glass sheet in the advancing direction is preferably controlled by the cooling rate control member. The cooling rate control member can make the temperature of the width direction of a glass sheet uniform.

Moreover, it is preferable that the edge part cooling apparatus which cools the edge part of the width direction of a glass sheet in the space where the glass sheet spaced apart from the molded object is cooled is provided. In a cooling process, a glass sheet is cooled by the edge part cooling apparatus so that the edge part of a glass sheet may be cooled at a speed larger than the center area | region of a glass sheet. The end cooling device can suppress shrinkage in the width direction of the glass sheet.

Moreover, it is preferable that the heat insulating member is provided in the surface on the opposite side to the opposing surface of a glass sheet of a cooling rate control member along the width direction of a glass sheet. In a cooling process, the thickness and / or curvature of the width direction of a glass sheet are controlled by a heat insulating member.

In addition, in a cooling process, in at least one part of the space until the temperature of the center area | region of a glass sheet becomes the softening point vicinity, a glass sheet is changed according to the plate thickness distribution of the width direction of a glass sheet by changing the dimension of a thermal insulation member. It is preferable that the thickness of is controlled.

In a cooling process, the temperature distribution of the width direction of a glass sheet can be controlled by using a heat insulating member. Thereby, in a cooling process, the temperature distribution of a suitable glass sheet can be implement | achieved in order to reduce the plate | board thickness deviation and curvature of a glass sheet.

In addition, in the cooling process, after the thickness of the glass sheet is controlled, a temperature profile is formed in which the temperature of the glass sheet decreases stepwise or continuously from the central region of the glass sheet to the end portion by changing the dimensions of the thermal insulation member, It is preferable that the curvature of a glass sheet is controlled so that a top view may be in a predetermined range.

The cooler which concerns on this invention is a cooler for cooling a space, and is equipped with a heat insulation board and a refrigerant pipe. The heat insulating plate divides the space into a plurality of cooling chambers, and further suppresses heat movement between adjacent cooling chambers. The coolant pipe cools the cooling chamber by the flow of the liquid coolant therein.

In this cooler, the refrigerant pipe performs efficient heat exchange by radiant heat transfer and natural convective heat transfer between the liquid refrigerant flowing therein and one of the two spaces separated by the heat insulating plate. This cooler can control the amount of heat exchange by adjusting the flow rate of the liquid refrigerant inside the refrigerant pipe, changing the temperature of the liquid refrigerant, and changing the surface area of the refrigerant pipe by changing the number of round trips of the refrigerant pipe.

Therefore, this cooler can perform heat exchange with a heat source efficiently and excellent in controllability in the space where a heat source exists.

In addition, it is preferable that the coolant pipe is arranged so as to reciprocate a plurality of times at intervals equal to or more than the outer diameter, and further, to form a pipe plane in which the reciprocating coolant pipe is a plane made of heat. The heat insulation plate constitutes one surface in the wall surface of the cooling chamber, and is provided over its own weight on the column of the refrigerant pipe while being in parallel with the pipe plane and in contact with the pipe plane.

Since the cooler can take a large surface area of the cooling tube in contact with the surrounding atmosphere, the heat exchanger can perform more efficient heat exchange with the heat source in the space where the heat source exists. Moreover, since the dimension of the vertical direction of a cooling pipe is small, this cooler can be installed even if the dimension of the vertical direction of an installation space is restrict | limited without reducing heat exchange efficiency.

In addition, it is preferable that the cooler has rigidity of 20 mm or less regardless of the length in the longitudinal direction, the amount of warpage caused by the weight of the central portion in the longitudinal direction in a state where both ends thereof are supported. Therefore, this cooler does not require the support in the center part of the longitudinal direction.

The manufacturing method of the glass substrate which concerns on this invention can perform heat exchange with a glass sheet efficiently and excellent in controllability in the space where the molded glass sheet is cooled. The cooler which concerns on this invention can perform efficient heat exchange with a heat source in the space where a heat source exists.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the glass substrate manufacturing apparatus which concerns on this embodiment liquid.
2 is a front view of the molding apparatus.
It is sectional drawing of the shaping | molding apparatus in the III-III line | wire of FIG.
4 is an external view of a cooling rate control member.
5 is an enlarged view of FIG. 2 in the vicinity of the cooling rate control member.
6 is an external view of an end cooling device.
7 is an external view of the cooler.
8 is a side view of the cooler.
9 is a top view of a cooler according to a modification A. FIG.
10 is a side view of a cooler according to a modification A. FIG.

(1) the overall configuration of the glass substrate manufacturing apparatus

EMBODIMENT OF THE INVENTION The manufacturing method of the glass substrate which concerns on this invention, and embodiment of a cooler are demonstrated, referring drawings. 1: is a schematic block diagram of the glass substrate manufacturing apparatus 100 used by this embodiment. The glass substrate manufacturing apparatus 100 is comprised from the dissolution tank 200, the clarification tank 300, and the shaping | molding apparatus 400 as shown in FIG. In the melting tank 200, a glass raw material is heated and a molten glass is produced. In the clarification tank 300, the bubble contained in the molten glass produced | generated in the dissolution tank 200 is removed. In the shaping | molding apparatus 400, a glass sheet is shape | molded continuously by the overflow down draw method from the molten glass from which the bubble was removed in the clarification tank 300. The molded glass sheet is cut into predetermined dimensions to obtain a glass substrate of product size. The glass substrate is packed and shipped through an end surface processing step, a washing step, an inspection step, and the like.

The glass substrate manufactured by the glass substrate manufacturing apparatus 100 is used for manufacture of flat panel displays (FPD), such as a liquid crystal display, a plasma display, and an organic electroluminescent display. This glass substrate has a thickness of, for example, 0.2 mm to 0.8 mm, and also has dimensions of 680 mm to 2200 mm in length and 880 mm to 2500 mm in width.

(2) detailed configuration of the molding apparatus

2 is a front view of the molding apparatus 400. FIG. 2: is an external view of the shaping | molding apparatus 400 seen along the direction perpendicular | vertical to the surface of the glass sheet 90 shape | molded by the shaping | molding apparatus 400. FIG. FIG. 3: is sectional drawing of the shaping | molding apparatus 400 in the III-III line | wire of FIG. The molding apparatus 400 mainly includes the molded body 10, the upper partition member 20, the cooling roller 30, the cooling unit 40, the coolers 51a to 51f, and the lower partition member 60. And a pulling down roller 70 and a control device (not shown).

(2-1) Molded body

As shown in FIG. 3, the molded body 10 has a substantially wedge shape and a pentagonal cross-sectional shape. The molded body 10 is formed of a refractory brick and is provided in the molded body accommodating space 410 which is a space above the upper partition member 20. The molded body 10 is provided so that the tip of the cross-sectional shape of a substantially wedge shape may be located in a lower end part.

The groove 12 is formed in the upper end surface of the molded object 10 along the longitudinal direction of the molded object 10. The glass supply pipe 14 which communicates with the groove 12 is provided in the edge part of the longitudinal direction of the molded object 10. The groove 12 is gradually formed to become shallow as it goes to the other end from one end which communicates with the glass supply pipe 14.

The molten glass sent from the clarification tank 300 flows into the groove 12 via the glass supply pipe 14. The molten glass 80 which overflowed from the groove | channel 12 of the molded object 10 flows down on both sides of the molded object 10, and joins in the vicinity of the lower end part of the molded object 10. As shown in FIG. The joined molten glass 80 becomes the glass sheet 90. The glass sheet 90 is continuously shape | molded, and it cools down in the cooling space 420 which is space below the upper partition member 20, and above the lower partition member 60. As shown in FIG.

(2-2) upper partition member

The upper partition member 20 is a pair of plate-shaped heat insulation members provided in the vicinity of the lower end of the molded object 10. The upper partition member 20 is provided in the both sides of the thickness direction of the glass sheet 90, as shown in FIG. The upper partition member 20 partitions the molded body receiving space 410 and the cooling space 420 in the vertical direction. The molded body receiving space 410 is a space where the molded body 10 is installed. The cooling space 420 is a space in which the glass sheet 90 cools while falling. The upper partition member 20 blocks the movement of heat from the molded body receiving space 410 to the cooling space 420.

(2-3) Cooling roller

The cooling roller 30 is a member for quenching the glass sheet 90 which flows down the cooling space 420. The cooling roller 30 cools the both ends of the width direction of the glass sheet 90 as shown in FIG. The cooling roller 30 is provided in the both sides of the thickness direction of the glass sheet 90 as shown in FIG. Therefore, the glass sheet 90 is quenched by fitting the both ends of the width direction by the two cooling rollers 30.

(2-4) cooling unit

The cooling unit 40 is a unit which cools the glass sheet 90 to the vicinity of a slow cooling point, adjusting the cooling rate of the glass sheet 90 which flows down the cooling space 420. Here, the temperature near the slow cooling point is the temperature from the temperature which added 100 degreeC to the slow cooling point of the glass sheet 90, to the temperature which added the strain point of the glass sheet 90 and the slow cooling point of the glass sheet 90, and divided by two. Area. The cooling unit 40 is controlled to cool the glass sheet 90 stepwise or continuously along the flow direction of the glass sheet 90. The cooling unit 40 mainly has cooling rate control members 41a-41f, the edge part cooling apparatus 42, and the heat retention member 43. As shown in FIG.

(2-4-1) Cooling speed control member

In this embodiment, as shown in FIG. 3, six cooling speed control members 41a to 41f are provided in the cooling space 420 below the upper partition member 20. Cooling rate control members 41a-41f are provided along the flow direction of the glass sheet 90, ie, a perpendicular direction. The cooling rate control members 41a to 41f are arranged without a gap in the vertical direction. In addition, the number of the cooling rate control members 41a-41f arrange | positioned in a perpendicular direction differs in the cooling of the dimension of the shaping | molding apparatus 400 and the cooling process to the vicinity of the slow cooling point of the glass sheet 90 to each other. The number may be appropriately determined depending on the number of speed patterns and the like.

The cooling rate control member 41a is provided most upstream with respect to the flow direction of the glass sheet 90 among the six cooling rate control members 41a-41f. The cooling rate control member 41f is provided most downstream of the six cooling rate control members 41a to 41f with respect to the flow direction of the glass sheet 90. The cooling rate control member 41a is provided adjacent to the lower portion of the upper partition member 20, and the cooling rate control member 41f is provided substantially above the lower partition member 60. Each cooling speed control member 41a-41f has the same structure. Next, the structure of the cooling rate control members 41a-41f is demonstrated, taking the cooling rate control member 41a as an example.

The pair of cooling rate control members 41a are respectively provided in the vicinity of both surfaces of the glass sheet 90. The cooling rate control member 41a is a member extending in the width direction of the glass sheet 90, that is, the horizontal direction. As shown in FIG. 2, the cooling rate control member 41a is provided at a position facing the surface of the central region 90a in the width direction of the glass sheet 90. Hereinafter, the central region 90a of the glass sheet 90 is an area including the portion of the object to make the plate thickness uniform, and the end 90b of the glass sheet 90 includes the portion of the object to be cut after production. Area. The length of the longitudinal direction of the cooling rate control member 41a is shorter than the length of the width direction of the glass sheet 90.

4 is an external view of a part of the cooling rate control member 41a. The cooling rate control member 41a is a plate-shaped metal member that is bent. It is preferable that this metal member has heat resistance of 600 degreeC or more in air | atmosphere, has a thermal conductivity of at least 30 W / m * K or more, and has emissivity characteristic of 0.85 or more in a use temperature range. The metal member of the cooling rate control member 41a is pure nickel, for example.

The cooling rate control member 41a is a channel (grooved steel) having a bent portion 62a and a main portion 63a, as shown in FIG. The bent part 62a is located at both ends of the vertical direction of the cooling rate control member 41a, and is a horizontal part formed by bending a metal member. The main portion 63a is a vertical portion other than the bent portion 62a. The main part 63a has a surface facing the glass sheet 90. The dimension h of the vertical part of the main part 63a is 50 mm-250 mm, for example. It is preferable that the main part 63a has a thickness t of 4 mm or more, for example. The horizontal dimension w of the bend part 62a is 40 mm-90 mm, for example.

5 is an enlarged view of FIG. 2 in the vicinity of the cooling rate control member 41a. In FIG. 5, the end cooling device 42 is omitted. As shown in FIG. 3, the cooling rate control member 41a is connected to the cooling rate control member 41b adjacent to the vertical direction by screwing. Specifically, the bent portion 62a at the lower side of the cooling rate control member 41a is connected to the bent portion 62b at the upper side of the cooling rate control member 41b by screwing. Similarly, the bent part 62b of the lower part of the cooling rate control member 41b is connected with the bent part 62c of the upper side of the cooling rate control member 41c by screwing.

In FIG. 3, the rear cooling space 422 is a space on which the cooling speed control members 41a to 41f are sandwiched and on the opposite side of the glass sheet 90. That is, the rear cooling space 422 is a space behind the cooling rate control members 41a to 41f as viewed from the glass sheet 90 side. The rear cooling space 422 is part of the cooling space 420. In the cooling space 420, the rear cooling space 422 is partitioned from a space other than the rear cooling space 422. Specifically, both side portions of the rear cooling space 422 in the width direction of the glass sheet 90 are partitioned by members such as channels having the same shape as the cooling rate control members 41a to 41f. The side portion of the rear cooling space 422 facing the cooling rate control members 41a to 41f is partitioned by the inner wall of the molding apparatus 400 and the heat insulating member. The upper part and the lower part of the rear cooling space 422 are partitioned by the cooler 51a and the lower partition member 60, respectively. The rear cooling space 422 is divided into the plurality of cooling chambers 422a to 422f along the advancing direction of the glass sheet 90 by the coolers 51b to 51f.

(2-4-2) end cooling device

The edge part refrigeration apparatus 42 is a unit which cools the both ends of the width direction of the glass sheet 90 in the cooling space 420. As shown in FIG. 2, the edge part cooling apparatus 42 is provided in the position which opposes the both surfaces of the glass sheet 90 in the both ends 90b of the width direction of the glass sheet 90. As shown in FIG. The edge part cooling apparatus 42 is provided in the both sides of the cooling rate control members 41a-41f in the width direction of the glass sheet 90. As shown in FIG. In addition, as shown in FIG. 2, the plurality of end cooling devices 42 are provided along the flow direction of the glass sheet 90.

6 is an external view of the end cooling device 42. The end cooling apparatus 42 is mainly comprised by the water cooling plate 42a, the water supply pipe 42b, and the drain pipe 42c. The water cooling plate 42a is made of a member having a relatively high thermal conductivity and excellent oxidation resistance and heat resistance. In this embodiment, the water cooling plate 42a is molded from stainless steel. The water cooling plate 42a has a flow path inside which the cooling water flows. The water supply pipe 42b and the drain pipe 42c communicate with the flow path of the water cooling plate 42a. The water cooling plate 42a has a surface corresponding to that of the glass sheet 90. The end cooling device 42 has a structure that can be brought close to or separated from the glass sheet 90.

Cooling water is supplied to the flow path of the water cooling plate 42a through the water supply pipe 42b. The cooling water warmed up through the flow path of the water cooling plate 42a is discharged from the drain pipe 42c. Both ends 90b in the width direction of the glass sheet 90 are cooled by radiant heat transfer from the water cooling plate 42a.

By the cooling rate control members 41a to 41f and the end cooling device 42, both ends 90b of the glass sheet 90 are cooled at a speed larger than the center region 90a of the glass sheet 90. Thereby, the edge part cooling apparatus 42 can suppress the shrinkage of the width direction of the glass sheet 90, and can form the temperature distribution required for the width direction of the glass sheet 90. As shown in FIG.

(2-4-3) thermal insulation member

As shown in FIG. 5, the heat insulating member 43 is fixed to the bent portion 62a on the lower side of the cooling rate control member 41a. That is, the heat retention member 43 is provided in the rear cooling space 422. As for the cooling rate control member 41a, the some thermal insulation member 43 is provided along the longitudinal direction. The heat insulating member 43 is a glass sheet 90 according to the volume distribution shape of the glass sheet 90 in at least one part of the space until the temperature of the center area 90a of the glass sheet 90 becomes near a softening point. Is intermittently and irregularly arranged in the width direction of the cross-section. Here, the softening point vicinity is a temperature range from the temperature which added 100 degreeC to the softening point of the glass sheet 90 to the temperature which removed 100 degreeC from the softening point of the glass sheet 90 here. The heat insulating member 43 is a glass sheet toward the both ends 90b from the center region 90a of the width direction of the glass sheet 90 in the space where the temperature of the center region 90a of the glass sheet 90 is lower than the softening point. In order to form the temperature profile which the temperature of 90 falls in steps or continuously, it is arrange | positioned substantially regularly in the width direction of the glass sheet 90, and without a clearance. Each of the other cooling rate control members 41b to 41f is provided with a plurality of heat insulating members 43 similarly to the cooling rate control member 41a.

The heat insulating member 43 suppresses heat radiation from the cooling rate control members 41a to 41f. The heat insulating member 43 is a ceramic fiber board and a blanket, for example. By the heat insulating member 43, the thickness and the curvature of the glass sheet 90 are controlled. For example, in at least a part of the space where the temperature of the center region 90a in the width direction of the glass sheet 90 is cooled to the vicinity of the softening point, the glass sheet 90 is appropriately adjusted by adjusting the dimensions of the thermal insulation member 43. The thickness of the glass sheet 90 is controlled according to the plate | board thickness distribution of the width direction of ().

Moreover, the temperature distribution of the width direction of the glass sheet 90 can be controlled by using the heat insulating member 43. Thereby, the temperature distribution of the suitable glass sheet 90 can be implement | achieved in order to reduce the plate | board thickness deviation and curvature of the glass sheet 90. FIG.

In addition, by appropriately adjusting the dimensions of the insulating member 43, the temperature profile at which the temperature of the glass sheet 90 decreases stepwise or continuously from the central region 90a of the glass sheet 90 toward both ends 90b is obtained. Can be formed. Thereby, the curvature of the glass sheet 90 is controlled so that a top view may exist in a predetermined range. In order to form such a temperature profile, the heat insulating member 43 provided in the center part of the longitudinal direction of the cooling rate control members 41b-41f is made thicker or higher than the heat insulating member 43 provided in both ends, for example.

(2-5) cooler

The coolers 51a to 51f are members that divide the rear cooling space 422 in the vertical direction along the advancing direction of the glass sheet 90. Each of the pair of rear cooling spaces 422 is divided into six cooling chambers 422a to 422f by five coolers 51b to 51f, as shown in FIG. The cooling chambers 422a-422f are spaces behind the cooling rate control members 41a-41f as viewed from the glass sheet 90 side, respectively. The cooling chamber 422a is located most upstream with respect to the flow direction of the glass sheet 90 among the six cooling chambers 422a-422f. The cooling chamber 422f is located most downstream of the six cooling chambers 422a-422f with respect to the flow direction of the glass sheet 90. FIG. Moreover, what is necessary is just to cool at least one part of cooling chambers 422a-422f by the coolers 51a-51f.

As shown in FIG. 3, the cooler 51a is provided in the height position of the bending part 62a of the upper side of the cooling rate control member 41a. The cooler 51b is provided at the height position between the cooling rate control member 41a and the cooling rate control member 41b. That is, the cooler 51b is provided in the height position between the cooling chamber 422a corresponding to the cooling rate control member 41a, and the cooling chamber 422b corresponding to the cooling rate control member 41b. Similarly, the cooler 51c is provided at the height position between the cooling rate control member 41b and the cooling rate control member 41c. That is, the cooler 51c is provided in the height position between the cooling chamber 422b corresponding to the cooling rate control member 41b, and the cooling chamber 422c corresponding to the cooling rate control member 41c. The same applies to the other coolers 51d to 51f.

The cooling chamber 422a is surrounded by the cooling rate control member 41a, the cooler 51a, and the cooler 51b, and the cooling chamber 422b includes the cooling rate control member 41b, the cooler 51b, and the cooler 51c. Surrounded by). The same applies to the cooling chambers 422c to 422e. The cooling chamber 422f is surrounded by the cooling rate control member 41f, the cooler 51f, and the lower partition member 60.

Each cooler 51a-51f has the same structure. Next, the structure of the cooler 51b is demonstrated. In addition, the following description is applicable also to the other coolers 51a, 51c-51f. The cooler 51b is mainly comprised by the heat insulation board 52b, the refrigerant pipe 53b, and the support part 54b. 7 is an external view of the cooler 51b viewed from below. 8 is a side view of the cooler 51b.

(2-5-1) insulation board

The heat insulation board 52b has a length substantially the same as the cooling rate control members 41a-41f in the width direction of the glass sheet 90. The heat insulation board 52b suppresses the movement of heat between the cooling chamber 422a and the cooling chamber 422b which are spaced apart by the cooler 51b.

The heat insulation board 52b is installed in the upper part of the cooler 51b. That is, FIG. 7 is an external view of the cooler 51b provided in the rear cooling space 422 viewed from below. The longitudinal direction of the heat insulation board 52b is parallel to the longitudinal direction of the cooling rate control members 41a-41f, and the width direction of the glass sheet 90. FIG. It is preferable that the heat insulation board 52b has a heat resistance of 0.07 m <2> * K / W or more.

(2-5-2) Refrigerant Pipe

The coolant pipe 53b is provided below the cooler 51b. The coolant pipe 53b is a pipe through which cooling water flows. The coolant pipe 53b is provided on the lower surface of the heat insulating plate 52b. The refrigerant pipe 53b is mainly composed of a plurality of square pipes 91, a plurality of long elbows 92, an inflow pipe 93, and an outflow pipe 94. In this embodiment, as shown in FIG. 7, the refrigerant pipe 53b has four square tubes 91 and three long elbows 92. As the square tube 91, the long elbow 92, the inflow tube 93, and the outflow tube 94, commercially available stainless steel pipes, copper pipes, and the like are used. Square tube 91 has a substantially square cross-sectional shape. The long elbow 92, the inflow pipe 93, and the outflow pipe 94 have a substantially circular cross-sectional shape.

Four square tubes 91 are provided in the lower surface of the heat insulation board 52b along the longitudinal direction of the heat insulation board 52b. Four square tubes 91 are provided in parallel with each other at predetermined intervals. The space | interval between the adjacent pipes 91 is more than the outer diameter of the pipes 91. As shown in FIG. 7, the long elbow 92 is a U-shaped tube that connects end portions of adjacent corner tubes 91. The inflow pipe 93 and the outflow pipe 94 are connected to the edge part of the two square pipes 91 provided in the both ends of the heat insulation board 52b. Two corner pipes 91 not connected to the inflow pipe 93 and the outflow pipe 94 are connected to two different corner pipes 91 and long elbows 92 at both ends thereof. The cross-sectional area of the long elbow 92 is almost equal to the cross-sectional area of the inflow pipe 93 and the outflow pipe 94. The cross-sectional area of the square tube 91 is less than four times the cross-sectional area of the inflow tube 93 and the outflow tube 94.

The water flowing inside the coolant pipe 53b is supplied from the inflow pipe 93, alternately flows through the square pipe 91 and the long elbow 92, and is discharged from the outflow pipe 94. As shown in FIG. 7, the water flowing inside the refrigerant pipe 53b reciprocates a plurality of times in the longitudinal direction of the heat insulating plate 52b.

(2-5-3) Support

The support part 54b is provided in the both sides of the cooler 51b. The pair of support portions 54b are respectively connected to the ends of the four square tubes 91. The tube 91 is fixed to the support part 54b by the thermoelectric cement 96, as shown in FIG. The upper end face of the four square tubes 91 is included in the tube plane 95, as shown in FIG. 8. The tube plane 95 is an imaginary plane that includes the top surfaces of four corner tubes 91. The pipe plane 95 is a plane parallel to the lower surface of the heat insulation plate 52b. The heat insulation board 52b is supported over its own weight on the upper end surface of the four square pipes 91 in the state which contacted the pipe plane 95. As shown in FIG. That is, the upper end surface of the four square tubes 91 is the surface adhere | attached with the lower surface of the heat insulation board 52b.

The support part 54b is being fixed to the wall surface which comprises the cooling space 420. As shown in FIG. The cooler 51b is provided in the rear cooling space 422 in a state where both ends thereof are supported by a pair of support portions 54b. The cooler 51b has rigidity whose curvature amount by the weight of the center part of the longitudinal direction is 20 mm or less.

(2-6) lower partition member

The lower partition member 60 is a plate-shaped heat insulation member provided below the cooling unit 40. The lower partition member 60 is provided in the both sides of the thickness direction of the glass sheet 90, as shown in FIG. The lower partition member 60 partitions the cooling space 420 and the slow cooling space 430 below the cooling space 420 in the vertical direction. The lower partition member 60 blocks the movement of heat from the cooling space 420 to the slow cooling space 430.

(2-7) pulling down roller

As shown in FIGS. 2 and 3, the pulling roller 70 is installed in the slow cooling space 430, and is a member for pulling down the glass sheet 90. The slow cooling space 430 is a space where the glass sheet 90 is gradually cooled while being pulled down by the pulling roller 70. The pulling-out roller 70 is provided in the both ends of the thickness direction of the glass sheet 90, and the both ends of the width direction of the glass sheet 90. As shown in FIG. The pulling down roller 70 rotates by a motor drive. By the rotation of the pulling roller 70, the glass sheet 90 is pulled down.

The average cooling rate of the glass sheet 90 until the temperature of the center region 90a of the glass sheet 90 becomes the slow cooling point is such that the temperature of the center region 90a of the glass sheet 90 becomes the strain point from the slow cooling point. It is larger than the average cooling rate of the glass sheet 90 until it becomes 50 degreeC lower temperature. The space to be cooled until the temperature of the central region 90a of the glass sheet 90 becomes the slow cooling point is the cooling space 420. The space to be cooled until the temperature of the central region 90a of the glass sheet 90 is 50 ° C lower than the strain point is a space of a part of the slow cooling space 430.

(2-8) Control device

The control device is mainly composed of a CPU, a RAM, a ROM, a hard disk, and the like. The control device is connected to the cooling roller 30, the end cooling device 42, the coolers 51a to 51f, the pulling down roller 70, and the like. The control device adjusts the rotation speed of the cooling roller 30 and the pulling roller 70, for example. The control device adjusts, for example, the flow rate of the cooling water passing through the water cooling plate 42a of the end cooling device 42. The control device adjusts, for example, the flow rate of the cooling water passing through the refrigerant pipe 53a of the cooler 51a.

(3) operation of the glass substrate manufacturing apparatus

The molten glass 80 which overflowed from the groove | channel 12 of the molded object 10 flows down on both sides of the molded object 10, and joins in the vicinity of the lower end part of the molded object 10. As shown in FIG. The joined molten glass 80 becomes the glass sheet 90. The glass sheet 90 is continuously molded and cooled while flowing down the cooling space 420 and the slow cooling space 430.

In the cooling space 420, the both ends of the width direction of the glass sheet 90 are quenched by the cooling roller 30 initially. Next, while the cooling rate of the glass sheet 90 is adjusted by the cooling unit 40, the glass sheet 90 is cooled to the vicinity of a slow cooling point. In the slow cooling space 430, the glass sheet 90 is gradually cooled while being pulled down by the pulling roller 70. The cooled glass sheet 90 is cut into predetermined dimensions, whereby a glass substrate of product size is obtained.

(4) Features of Glass Substrate Manufacturing Apparatus

(4-1)

In the cooler 51b which concerns on this embodiment (it is the same also about other coolers 51a, 51c-51f hereafter), the cross-sectional area of each tube 91 is the long elbow 92, the inflow pipe 93, and the outflow pipe. It is less than four times the cross-sectional area of 94, and the connection portion of the inlet tube 93 and the square tube 91, the connection portion of the square tube 91 and the long elbow 92, and the connection portion of the square tube 91 and the outlet tube 94 Therefore, the rate of change of the cross-sectional area of the flow path of the refrigerant pipe 53b is suppressed to less than a predetermined value. That is, the entire flow path of the refrigerant pipe 53b does not have a portion where the flow path cross-sectional area is rapidly enlarged and a portion where the flow path cross-sectional area is rapidly reduced.

When the refrigerant pipe through which the liquid refrigerant used for heat exchange flows has a portion where the flow path cross-sectional area changes drastically, a portion where the flow of the refrigerant stays inside the refrigerant tube occurs. In the portion where the coolant stays, the heat exchange efficiency between the coolant flowing through the coolant tube and the atmosphere around the coolant tube is reduced. In addition, when the cleanliness of the coolant is low, there is a possibility that impurities contained in the coolant settle and accumulate in the portion where the coolant stays, causing the coolant pipe to be clogged. In addition, when the flow path cross-section of the coolant pipe is complicated, such as a drastic change in the cross-sectional area, there is a fear that the air inside the coolant pipe is not completely exhausted when the coolant pipe is filled with the coolant. As a result, there is a possibility that the refrigerant pipe wall surface that is not in contact with the refrigerant is locally heated and oxidized, resulting in damage.

In the present embodiment, as described above, since the coolant pipe 53b does not have a portion where the flow path cross-sectional area changes drastically, the generation of the portion where the coolant stays is suppressed. Therefore, it is suppressed that the efficiency of heat exchange between the refrigerant flowing inside the refrigerant pipe 53b and the ambient atmosphere of the refrigerant pipe 53b is suppressed, and clogging of the refrigerant pipe 53b with impurities contained in the refrigerant is suppressed. . Moreover, since generation | occurrence | production of the part which the air stays in the refrigerant pipe 53b is suppressed, it is suppressed that the wall surface of the refrigerant pipe 53b is locally heated and broken.

Therefore, since the coolers 51a-51f which concern on this embodiment can suppress the fall of heat exchange efficiency, the glass substrate manufacturing apparatus 100 provided with the coolers 51a-51f cools the molded glass sheet 90. In the cooling space 420 which becomes, WHEREIN: Heat exchange with the glass sheet 90 can be performed efficiently.

(4-2)

In the cooler 51b which concerns on this embodiment, the upper end surface of the four square pipes 91 which comprise the refrigerant pipe 53b is contained in the same pipe plane 95. As shown in FIG. The heat insulation board 52b is supported by four square tubes 91. As shown in FIG. The heat insulating plate 52b separates the cooling chamber 422a above the cooler 51b, and the lower cooling chamber 422b of the cooler 51b. Therefore, the movement of airflow does not occur between the cooling chamber 422a and the cooling chamber 422b, and thermal movement is interrupted | blocked.

Thereby, heat exchange between the refrigerant pipe 53b provided in the lower surface of the heat insulation board 52b, and the atmosphere of the cooling chamber 422b below the cooler 51b is performed. On the other hand, heat exchange between the refrigerant pipe 53b and the atmosphere of the cooling chamber 422a above the cooler 51b is suppressed by the heat insulating plate 52b. That is, the cooler 51b adjusts the temperature of the cooling rate control member 41b in contact with the cooling chamber 422b without affecting the temperature of the cooling rate control member 41a in contact with the cooling chamber 422a. Can be.

Therefore, the coolers 51a to 51f can adjust only the temperatures of the cooling rate control members 41a to 41f, respectively. Thereby, the temperature of each cooling speed control member 41a-41f can be adjusted independently, for example by controlling the flow volume of the refrigerant | coolant which passes through each cooler 51a-51f using a control apparatus.

Therefore, the coolers 51a to 51f according to the present embodiment can perform heat exchange with the glass sheet 90 efficiently and with excellent controllability through the cooling rate control members 41a to 41f. Thereby, cooler 51a-51f can control the cooling rate of the glass sheet 90 suitably.

(4-3)

In the cooler 51b which concerns on this embodiment, four square tubes 91 are arrange | positioned in parallel with each other at intervals. The upper end surface of each corner tube 91 is adhere | attached on the lower surface of the heat insulation board 52b. Therefore, three surfaces other than the upper end surface of each tube 91 of the cooler 51b are in contact with the atmosphere of the cooling chamber 422b. Thus, since the four square tubes 91 are arrange | positioned at intervals, the surface area of the square tube 91 which contacts the cooling chamber 422b can be taken large, and the heat exchange efficiency of the cooler 51b improves.

Therefore, since the coolers 51a to 51f according to the present embodiment have high heat exchange efficiency, the glass substrate manufacturing apparatus 100 including the coolers 51a to 51f has a cooling space 420 in which the glass sheet 90 is cooled. ), Heat exchange can be efficiently performed with the glass sheet 90. In addition, the structure in which four square tubes 91 are arrange | positioned at intervals can implement | achieve the weight reduction of the cooler 51b.

(4-4)

In the cooler 51b which concerns on this embodiment, the square tube 91 which occupies most of the flow path of the refrigerant pipe 53b is provided in the lower surface of the heat insulation board 52b, and also the long elbow 92 and the inflow pipe 93 are carried out. And only the outflow pipe 94 protrudes downward from the lower end surface of the square pipe 91, as shown in FIG. The long elbow 92, the inflow pipe 93, and the outflow pipe 94 are connected to the edge part of the square pipe 91. As shown in FIG. Therefore, except for the longitudinal direction both ends of the cooler 51b, the height dimension of the cooler 51b is settled within the value which combined the height dimension of the heat insulation board 52b, and the height dimension of the square tube 91.

Therefore, the coolers 51a to 51f according to the present embodiment can suppress the height dimension except for both ends in the longitudinal direction. Therefore, even when the height dimension of the cooling space 420 is limited, several coolers 51a-51f can be provided without reducing heat exchange efficiency.

(4-5)

In the cooler 51b which concerns on this embodiment, commercially available stainless steel pipes and copper are the square tube 91, the long elbow 92, the inflow pipe 93, and the outflow pipe 94 which comprise the refrigerant pipe 53b. Pipes and the like are used. In addition, in order to assemble the refrigerant pipe 53b, the connection portion of the square tube 91 and the long elbow 92, the connection portion of the square tube 91 and the inlet tube 93, and the connection portion of the square tube 91 and the outlet tube 94 It is only necessary to weld it around.

Therefore, since the coolers 51a-51f which concern on this embodiment are equipped with the refrigerant pipe 53b which has a simple structure, the number of processes and cost for assembling the refrigerant pipe 53b can be suppressed.

(4-6)

In the cooler 51b which concerns on this embodiment, the both ends of each tube 91 are fixed to the pair of support part 54b by the thermoelectric cement 96. As shown in FIG. Since the thermoelectric cement 96 has a high thermal conductivity, the support part 54b is easy to be cooled by the coolant which flows in the inside of the each tube 91.

Since one end part of the support part 54b is located in the vicinity of the cooling rate control member 41b, it is easy to be heated by the heat of the glass sheet 90 which falls. If the support 54b is heated and oxidized, the support 54b may be broken and thermally deformed.

In this embodiment, since the support part 54b is easy to cool by the refrigerant | coolant which flows in the inside of the each tube 91, breakage and thermal deformation of the support part 54b are suppressed.

(4-7)

The cooler 51b which concerns on this embodiment is provided in the state which the both ends were supported by the pair of support part 54b. The cooler 51b has the rigidity of 20 mm or less of curvature amount by the self weight of the center part of the longitudinal direction, regardless of the dimension of the longitudinal direction. Therefore, even in the state where only the both ends of the cooler 51b are supported by the pair of support parts 54b, the center part of the cooler 51b is hardly suspended by own weight. That is, the center part of the cooler 51b does not need to be supported by the other support member.

Therefore, since the cooler 51b does not have to be supported by the other support member in the center part of the longitudinal direction, the fall of heat exchange efficiency can be suppressed. Moreover, the cooler 51b cannot prevent access to the space near the center part in the longitudinal direction. Therefore, the rear cooling space 422 in which the cooler 51b is provided can be efficiently used in the longitudinal direction of the cooler 51b.

(4-8)

In the glass substrate manufacturing apparatus 100 which concerns on this embodiment, in the cooling space 420, some cooling speed control members 41a-41f are provided along the flow direction of the glass sheet 90. As shown in FIG. The cooling rate control members 41a to 41f are in contact with the cooling chambers 422a to 422f, respectively. Cooling chambers 422a to 422f are respectively cooled by coolers 51a to 51f. That is, the coolers 51a to 51f respectively adjust the temperatures of the cooling rate control members 41a to 41f. Thereby, the cooling rate of the glass sheet 90 cooled while falling is controlled.

In the conventional glass substrate manufacturing apparatus, in order to cool the glass sheet immediately after spaced apart from the lower end part of a molded object, for example, the method of adjusting the temperature of a glass sheet by spraying the gas for cooling to a cooling rate control member, It was used. However, in this method, since the temperature difference of a glass sheet arises because of the slight flow rate difference in the glass sheet width direction of the gas injected to a cooling rate control member, it is difficult to adjust the temperature of a glass sheet. Moreover, there exists a possibility that the temperature difference of a glass sheet may arise because a part of the gas injected to a cooling rate control member leaks unintentionally and collides with a glass sheet. Therefore, in this method, since it is difficult to adjust the cooling rate of a glass sheet, there exists a problem that the plate | board thickness variation of a glass sheet increases.

In the glass substrate manufacturing apparatus 100 which concerns on this embodiment, the coolers 51a-51f can respectively adjust the temperature of the cooling rate control members 41a-41f independently. Therefore, the coolers 51a to 51f can easily adjust the cooling rate of the glass sheet 90 to a desired value along the flow direction of the glass sheet 90. Therefore, the glass substrate manufacturing apparatus 100 can mass-produce the glass sheet 90 without increasing the plate thickness variation of the glass sheet 90.

(5) Modifications

(5-1) Modification Example A

In the cooler 51b according to the present embodiment (hereinafter also the same applies to the other coolers 51a, 51c to 51f), the square tube 91 through which the refrigerant for heat exchange flows is a tube having a substantially square cross-sectional shape. . However, a circular tube having a substantially circular cross-sectional shape may be used instead of the square tube 91.

9 and 10 show a cooler 151b which is a modification of the cooler 51b according to the present embodiment. 9 is a top view of the cooler 151b. 10 is a side view of the cooler 151b. The cooler 151b is mainly comprised by the heat insulation board 152b, the refrigerant pipe 153b, and the support part 154b. In addition, the cooler 151b is arrange | positioned at the same position as the cooler 51b which concerns on this embodiment, and has the same effect.

The heat insulation board 152b and the support part 154b of the cooler 151b have the same structure as the heat insulation board 52b and the support part 54b of the cooler 51b which concerns on this embodiment, respectively. The coolant tube 153b of the cooler 151b has a structure different from the coolant tube 53b of the cooler 51b which concerns on this embodiment. As shown in FIG. 9, the refrigerant pipe 153b includes four circular tubes 191, three long elbows 192, an inlet tube 193, and an outlet tube 194. The cross-sectional area of the raw tube 191 is substantially the same as the cross-sectional areas of the long elbow 192, the inflow pipe 193, and the outflow pipe 194. The long elbow 192, the inflow pipe 193, and the outflow pipe 194 are fixed to the support 154b by the thermoelectric cement 196.

Four circular tubes 191 are arranged parallel to each other at intervals. The upper end of each round tube 191 is adhere | attached on the lower surface of the heat insulation board 152b. The inflow pipe 193 and the outflow pipe 194 are connected to the ends of two circular pipes 191 provided at both ends of the heat insulating plate 152b. The two original pipes 191 which are not connected to the inlet pipe 193 and the outflow pipe 194 are connected to two different raw pipes 191 and the long elbow 192 at both ends.

In the present modification, as shown in FIG. 10, the long elbow 192 and the inflow pipe 193 are provided at the same height position as the original pipe 191. Outflow pipe 194 is in the lower position than the original pipe 191 in the portion except the connection of the original pipe 191.

The cooling water flowing inside the refrigerant pipe 153b flows in from the inflow pipe 193, alternately flows through the original pipe 191 and the long elbow 192, and flows out of the outflow pipe 194. As shown in FIG. 9, the cooling water flowing inside the refrigerant pipe 153b reciprocates a plurality of times in the longitudinal direction of the heat insulating plate 152b.

In this modification, the coolant pipe 153b of the cooler 151b has a circular pipe 191. The primary tube 191 has a smaller adhesion area with the heat insulating plate 152b than the square tube 91 of the present embodiment. However, the surface area of the raw tube 191 which contact | connects the cooling chamber below the heat insulation board 152b is large by the structure by which four circular tube 191 is arrange | positioned at intervals. Therefore, the cooler 151b has high heat exchange efficiency similarly to the cooler 51b which concerns on this embodiment.

(5-2) Variation B

In the cooler 51b which concerns on this embodiment, the refrigerant pipe 53b is arrange | positioned so that it may reciprocate plural times at intervals. Specifically, the refrigerant flowing inside the refrigerant pipe 53b reciprocates twice along the longitudinal direction of the heat insulating plate 52b by passing through the four square tubes 91. However, the number of round trips of the coolant pipe 53b may be appropriately changed depending on the cross-sectional area of each pipe 91 and the dimensions of the heat insulating plate 52b.

In addition, the cross-sectional area of the square tube 91 may also be appropriately changed. In this embodiment, the cross-sectional area of the square pipe 91 is less than four times the cross-sectional area of the inflow pipe 93 and the outflow pipe 94. However, it is preferable that the cross-sectional area of each tube 91 is substantially the same as that of the inlet tube 93 and the outlet tube 94. As a result, the rate of change in the cross-sectional area of the flow path of the coolant pipe 53b at the connection portion between the square pipe 91 and the inflow pipe 93 is suppressed, whereby a portion where the flow of the coolant stays becomes more difficult to occur.

(5-3) Variation C

In the cooler 51b which concerns on this embodiment, the square tube 91 of the refrigerant pipe 53b is shape | molded with a stainless steel pipe, a copper pipe, etc. In FIG. Three surfaces other than the upper end surface of each tube 91 are in contact with the atmosphere of the cooling chamber 422b. Therefore, the high emissivity paint may be apply | coated to three surfaces other than the upper end surface of the square tube 91. FIG. Thereby, since the absorption rate of the thermal radiation of each tube 91 increases, the heat exchange efficiency of the refrigerant which flows inside each tube 91 and the atmosphere of the cooling chamber 422b improves.

In addition, before apply | coating a high emissivity coating material to the surface of the square tube 91, you may sandblast the surface of the square tube 91. FIG. Thereby, the adhesiveness of the high emissivity paint on the surface of the square tube 91 improves.

(5-4) Variation example D

In the cooler 51b which concerns on this embodiment, the refrigerant pipe 53b has four square tubes 91. As shown in FIG. However, of the four square tubes 91, the square tube 91 which is easy to be heated at a position near the heat source may be replaced with the original tube 191 of "Modification A". Specifically, the square tube 91 at the position closest to the cooling rate control members 41a to 41f may be replaced with the original tube 191.

In the square tube 91 at the position closest to the cooling speed control members 41a to 41f, between an opposing surface that is a surface facing the cooling speed control members 41a to 41f, and a surface connected at right angles to the opposing surface. In, the amount of heat received by heat radiation heat conduction differs greatly. Therefore, since a large temperature difference generate | occur | produces in this square tube 91 along the surface, there exists a possibility that a big stress may generate | occur | produce in the corner part of the square tube 91 by the heat deformation resulting from the temperature difference. As a result, the corner tube 91 may be damaged. Therefore, it is preferable that the square tube 91 located in the position near the heat source is replaced with the original tube 191.

(5-5) Variation E

In the present embodiment, pure nickel is used as the material of the cooling rate control members 41a to 41f, but other materials having high thermal conductivity, such as molybdenum, sintered SiC, recrystallized SiC, artificial graphite, iron and tungsten, may be used. do.

However, molybdenum is preferably used in a non-oxidizing atmosphere. In addition, when molybdenum is used in an oxidizing atmosphere, it is preferable to apply an oxidation resistant coat to the cooling rate control members 41a to 41f. In addition, sintered SiC and recrystallized SiC can be used in an oxidizing atmosphere, and artificial graphite, iron, and tungsten can be used in a non-oxidizing atmosphere.

(5-6) Variation Example F

In this embodiment, although the channel (groove-type steel) is used as the cooling rate control members 41a-41f, the metal member which has another shape may be used. In this case, it is preferable that the heat conduction between adjacent cooling speed control members 41a to 41f is suppressed by minimizing the contact between the cooling speed control members 41a to 41f adjacent to each other in the vertical direction.

(5-7) Variation example G

In this embodiment, as the glass substrate manufacturing apparatus 100 for cooling the glass sheet 90 whose length in a width direction is 2200 mm, the length of a cooling speed control member 41a-41f, and a cooling speed control member are shown. The number of (41a-41f) was illustrated. However, according to the length and thickness of the width direction of the glass sheet 90 manufactured by the glass substrate manufacturing apparatus 100, etc., the length of the cooling direction control members 41a-41f, and the cooling speed control member 41a- the The number of 41f) may be changed.

(5-8) Modification H

In the present embodiment, the main portion 63a of the cooling rate control member 41a extends in the vertical direction, but may be inclined with respect to the vertical direction or an uneven portion may be formed along the vertical direction, for example. Thereby, the rising airflow generated along the surface of the glass sheet 90 can be suppressed, and the difference of the cooling rate of the glass sheet 90 in a perpendicular direction can be suppressed. Therefore, in this modification, in the cooling space 420, the glass sheet 90 can be cooled at a substantially constant speed.

(5-9) Modification I

In this embodiment, the rear cooling space 422 is divided into six cooling chambers 422a-422f along the advancing direction of the glass sheet 90 by five coolers 51b-51f. However, as long as at least part of the rear cooling space 422 is divided by the coolers 51a to 51f, the rear cooling space 422 may be divided by another heat insulating member or the like.

(5-10) Modification J

In the present embodiment, the cooling chambers 422a to 422f are respectively cooled by the coolers 51a to 51f. However, if at least part of the cooling chambers 422a to 422f is cooled by the coolers 51a to 51f, for example, the cooling chambers 422a to 422f may be provided to coolers and other cooling means having a different configuration from the coolers 51a to 51f according to the present embodiment. May be cooled.

10: Molded body
41a to 41f: cooling rate control member
42: end cooling device
43: thermal insulation member
51a to 51f: cooler
52b: heat insulation plate
53b: refrigerant pipe
80: molten glass
90: glass sheet
95: tube flat
422 rear cooling space
422a to 422f: cooling chamber

Claims (10)

A molding step of forming a glass sheet by overflowing the molten glass from the molded body,
A cooling step of cooling while extending the molded glass sheet downward;
Cutting process of cutting the cooled glass sheet to obtain a glass substrate
And,
In at least a part of the space to be cooled until the glass sheet spaced apart from the molded body becomes near the slow cooling point, a cooling rate control member is provided that faces the surface of the central region in the width direction of the glass sheet. Become,
The rear cooling space on the opposite side of the glass sheet with the cooling rate control member interposed therebetween comprises a cooling chamber arranged along the traveling direction of the glass sheet,
At least a portion of the cooling chamber is cooled by a cooler,
In the cooling step, the glass sheet is cooled stepwise or continuously by moving along the advancing direction while facing the cooling rate control member in contact with the cooling chamber,
At least part of the cooler,
A heat insulation plate for suppressing heat movement between the cooling chamber and a space adjacent to the cooling chamber along the advancing direction;
A refrigerant pipe cooling the cooling chamber by the flow of a liquid refrigerant therein
Having
A method of manufacturing a glass substrate. The method according to claim 1,
A first cooling step of cooling the glass sheet at a first average cooling rate until the temperature of the central region of the glass sheet becomes a slow cooling point;
2nd cooling process in which the said glass sheet is cooled by a 2nd average cooling rate until the temperature of the said center area | region of the said glass sheet becomes 50 degreeC lower than a strain point from a slow cooling point.
Lt; / RTI &
The first average cooling rate is greater than the second average cooling rate,
A method of manufacturing a glass substrate. The cooling rate of the said glass sheet in the said advancing direction is controlled by the said cooling rate control member in the said cooling process, The cooling rate of Claim 1 or 2
A method of manufacturing a glass substrate. The edge cooling apparatus of Claim 1 or 2 which cools the edge part of the width direction of the said glass sheet in the space where the said glass sheet spaced apart from the said molded object is cooled,
In the said cooling process, the said glass sheet is cooled by the said edge part cooling apparatus so that the said edge part of the said glass sheet may be cooled at a speed larger than the said center area | region of the said glass sheet,
A method of manufacturing a glass substrate. The heat insulation member of Claim 1 or 2 is provided in the surface of the said cooling rate control member on the opposite side to the opposing surface of the said glass sheet along the width direction of the said glass sheet,
In the said cooling process, the thickness and / or curvature of the width direction of the said glass sheet are controlled by the said thermal insulation member,
A method of manufacturing a glass substrate. The width | variety of the said glass sheet of Claim 5 by the change of the dimension of the said heat insulating member in at least one part of space until the temperature of the said center area | region of the said glass sheet becomes near a softening point in the said cooling process. The thickness of the glass sheet is controlled according to the plate thickness distribution in the direction,
A method of manufacturing a glass substrate. In the said cooling process, after the thickness of the said glass sheet is controlled, the temperature of the said glass sheet is changed toward the said edge part from the said center area | region of the said glass sheet by changing the dimension of the said thermal insulation member. A temperature profile is formed which is stepped down or continuously, and the warping of the glass sheet is controlled so that the top view is within a predetermined range,
A method of manufacturing a glass substrate. As a cooler for cooling the space,
A heat insulation plate that divides the space into a plurality of cooling chambers and further suppresses thermal movement between adjacent cooling chambers;
A refrigerant pipe cooling the cooling chamber by the flow of a liquid refrigerant therein
With
cooler. The coolant pipe according to claim 8, wherein the coolant pipe is arranged to reciprocate a plurality of times at intervals greater than or equal to its outer diameter, and the reciprocating coolant pipe forms a pipe plane that is a plane made of heat.
The heat insulating plate constitutes one surface in the wall surface of the cooling chamber, and is provided over its own weight on the rows of the refrigerant pipes while being in parallel with the pipe plane and in contact with the pipe plane.
cooler. The said cooler has rigidity which is 20 mm or less in curvature amount by the self-weight of the longitudinal center part in the state in which the both ends are supported, regardless of the length of a longitudinal direction.
cooler.

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