WO2023032849A1 - Method for manufacturing plate glass, method for manufacturing wedge-shaped glass, and method for manufacturing laminated glass - Google Patents

Abstract

In the present invention, a molten metal bath is provided with an upstream wall, a downstream wall, and two side walls. Each of the two side walls includes a shoulder that reduces the width of the molten metal bath in the direction of advance of a glass ribbon. The ratio W/N of the distance W between the two side walls in a region upstream of the shoulders of the molten metal bath and the distance N between the two side walls in a region downstream of the shoulders of the molten metal bath is greater than 1.0 and no greater than 1.6. By heating a central section of the glass ribbon in the width direction in the upstream region of the molten metal bath more strongly than sections at both ends in the width direction, plate glass is manufactured in which the central section in the width direction is thicker than the sections at both ends.

Description

Method for manufacturing sheet glass, method for manufacturing wedge-shaped glass, and method for manufacturing laminated glass

The present invention relates to a method for manufacturing sheet glass, a method for manufacturing wedge-shaped glass, and a method for manufacturing laminated glass. In particular, the present invention relates to a method for manufacturing sheet glass having a convex cross section in the width direction perpendicular to the traveling direction of the glass ribbon (the central portion in the width direction is thicker than both ends in the width direction).

The thickness of plate glass manufactured by the float method is usually constant. However, for example, in a head-up display (hereinafter also referred to as HUD) that displays information on the windshield of an automobile, the thickness is not constant in order to prevent double images when viewed from the driver. No glass is desired. Therefore, a method for manufacturing sheet glass having a concave, convex, or tapered cross section in the width direction (hereinafter sometimes simply referred to as the width direction) perpendicular to the traveling direction of the glass ribbon has been studied (for example, patent References 1 and 2). Patent Literature 1 discloses that a wedge-shaped glass is obtained by cutting a sheet glass having a convex cross-sectional shape in which the center portion in the width direction is thicker than the both end portions in the width direction.

WO2016/117650 U.S. Pat. No. 7,122,242

A molten metal bath usually comprises an upstream wall, a downstream wall and two side walls. Each sidewall may be provided with a shoulder that reduces the width of the molten metal bath in the direction of travel of the glass ribbon to reduce the amount of molten metal in the bath. Thus, in a molten metal bath having shoulders on the side walls, the surface of the molten metal may flow in a direction opposite to the direction in which the glass ribbon travels, in areas not covered with the glass ribbon. Due to this reverse flow, it is sometimes observed that the glass ribbon on the surface of the molten metal advances while reciprocating (swinging) in the width direction.

In particular, as in Patent Document 1, when producing plate glass having a convex cross-section, the temperature at the center in the width direction of the glass ribbon is set lower than in the case of producing plate glass with a constant thickness, so the glass The ribbon becomes more viscous (the glass ribbon becomes harder), and is easily affected by the flow in the opposite direction, and the glass ribbon tends to swing. Then, as in Patent Document 1, when trying to manufacture wedge-shaped glass by cutting a plate glass having a convex cross-section, the position where the plate glass is cut is usually a fixed position, so if the swing occurs, the wedge-shaped glass is cut. The wedge angle of the glass varies from product to product.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing plate glass that can suppress reciprocating movement (swing) in the width direction of the glass ribbon. Furthermore, it aims at providing the manufacturing method of the wedge-shaped glass and laminated glass which can suppress the variation of the wedge angle of the wedge-shaped glass obtained by cutting the said plate glass. In the present invention, the glass having a convex shape means a glass ribbon in which the central portion in the width direction of the glass ribbon is thicker than both ends in the width direction, or plate glass obtained from the glass ribbon.

The above objects of the present invention are achieved by the following configurations.
[1] Making a plate glass by floating a glass ribbon on the surface of the molten metal in a molten metal bath and advancing it, and bringing a plurality of top rolls into contact with both ends of the glass ribbon in the width direction to form the glass ribbon into a plate shape. A manufacturing method comprising:
the molten metal bath comprises an upstream wall, a downstream wall and two side walls;
each of the two sidewalls includes a shoulder that reduces the width of the molten metal bath in the direction of travel of the glass ribbon;
A ratio W/N between the distance W between the two side walls in the region upstream of the shoulder of the molten metal bath and the distance N between the two side walls in the region downstream of the shoulder of the molten metal bath more than 1.0 and 1.6 or less,
A method for producing sheet glass, wherein the width direction both ends of the glass ribbon are heated more strongly than the width direction center portion of the glass ribbon in the upstream region of the molten metal bath, thereby producing a sheet glass that is thicker at the width direction center portion than at both end portions. .
[2] With respect to the length from the upstream wall to the downstream wall, at a position 20% from the upstream wall, the viscosity of the central portion in the width direction of the glass ribbon on the surface of the molten metal is 10̂(4.5 ) The method for producing sheet glass according to [1], wherein the glass ribbon is heated to a temperature of (dPa·sec) or more.
[3] At a position 20% from the upstream wall with respect to the length from the upstream wall to the downstream wall, the viscosity of the central portion in the width direction of the glass ribbon on the surface of the molten metal is 10̂(6.0 ) (dPa·sec) or less, the method for producing sheet glass according to [1] or [2], wherein the glass ribbon is heated.
[4] At a position 32% from the upstream wall with respect to the length from the upstream wall to the downstream wall, the temperature of the widthwise central portion of the glass ribbon on the surface of the molten metal and both widthwise ends of the molten metal The method for producing sheet glass according to any one of [1] to [3], wherein the difference from the temperature of the part is 62° C. or less.
[5] At a position 32% from the upstream wall with respect to the length from the upstream wall to the downstream wall, the viscosity of the central portion in the width direction of the glass ribbon on the surface of the molten metal is 10̂(4.7 ) The method for producing sheet glass according to any one of [1] to [4], wherein the glass ribbon is heated to a temperature of (dPa·sec) or more.
[6] At a position 32% from the upstream wall with respect to the length from the upstream wall to the downstream wall, the viscosity of the central portion in the width direction of the glass ribbon on the surface of the molten metal is 10̂(6.3 ) The method for producing sheet glass according to any one of [1] to [5], wherein the glass ribbon is heated to (dPa·sec) or less.
[7] The ratio of the maximum width in the width direction of the glass ribbon in the molten metal bath to the length in the width direction of the glass ribbon at the most downstream side of the molten metal bath is 1.4 to 2.2. ] to [6], the method for producing a plate glass.
[8] A width a of the glass ribbon at a position 35% from the upstream wall with respect to the length from the upstream wall to the downstream wall, and a widthwise length of the glass ribbon at the most downstream side of the molten metal bath. The method for producing a sheet glass according to any one of [1] to [7], wherein the ratio a/b of and to is 1.0 to 1.9.
[9] The length A of the glass ribbon in the width direction and the molten metal surface not covered with the glass ribbon at a position 20% from the upstream wall with respect to the length from the upstream wall to the downstream wall The method for producing sheet glass according to any one of [1] to [8], wherein the ratio A/B of the length B in the width direction of is 4 to 11.
[10] A method for producing wedge-shaped glass, comprising cutting the plate glass obtained by the method for producing plate glass according to any one of [1] to [9] to obtain wedge-shaped glass.
[11] The wedge-shaped glass has at least one convex surface,
On a line segment passing through the center of gravity G of the convex surface and connecting two opposite sides of the four sides of the convex surface at the shortest distance, among intersections of the line segment and the sides of the convex surface, the wedge-shaped glass is positioned horizontally. The first point is the point where the thickness of the wedge-shaped glass is smaller in the vertical direction when the glass is placed at If a point on the convex surface located at is the second point, a straight line connecting the first point and the second point forms an angle of 0.020° to 0.050° with the horizontal plane. , a method for producing a wedge-shaped glass according to [10].
[12] The method for producing wedge-shaped glass according to [10] or [11], wherein the ratio T/M between the maximum value T and the minimum value M of the thickness of the wedge-shaped glass is 1.10 to 1.40.
[13] Wedge-shaped glass is obtained by cutting the sheet glass obtained by the method for producing sheet glass according to any one of [1] to [9],
laminating and crimping the wedge-shaped glass and another plate glass via an intermediate film;
A method for producing laminated glass.
[14] The other sheet glass is the wedge-shaped glass,
[13] The method for manufacturing a laminated glass.
[15] The other sheet glass is a sheet glass having a constant thickness.
[14] The method for producing a laminated glass.

A method for manufacturing plate glass can be provided that can suppress the reciprocating movement of the glass ribbon in the width direction. Furthermore, it is possible to provide a method for manufacturing wedge-shaped glass and laminated glass, which can suppress variations in the wedge angle of the wedge-shaped glass obtained by cutting the sheet glass.

FIG. 1(A) is a view of the glass manufacturing apparatus viewed from the width direction, and FIG. 1(B) is a view of the glass manufacturing apparatus viewed from the thickness direction. FIG. 2A is a cross-sectional view in the width direction of the glass manufactured by the manufacturing method of one embodiment of the present invention, and FIG. It is a wedge-shaped glass obtained by 3(A) is a plan view of the windshield, FIG. 3(B) is a BB cross-sectional view of the windshield of FIG. 3(A), and FIG. ) is a cross-sectional view of the windshield of FIG. FIG. 4 is an enlarged view of the top roll. 5A and 5B are views showing a plate glass according to one embodiment of the present invention, FIG. 5A being a plan view and FIG. 5B being a cross-sectional view in the width direction.

An embodiment of the present invention will be described below. First, the configuration of a glass manufacturing apparatus (that is, a float plate glass manufacturing apparatus) will be described.

As shown in FIGS. 1(A) and 1(B), the glass manufacturing apparatus 1 includes a melting section 10, a forming section 20, and a slow cooling section 30. Note that the X direction in the drawing is the traveling direction of the glass ribbon G2, X1 is the upstream direction of the glass ribbon G2, and the X2 direction is the downstream direction of the glass ribbon G2. The Y direction in the drawing is the direction orthogonal to the traveling direction X of the glass ribbon G2, and is the width direction of the glass ribbon G2. The Z direction in the figure is the direction orthogonal to the traveling direction X and the width direction Y of the glass ribbon G2 (that is, the thickness direction of the glass ribbon G2), the Z1 direction is upward, and the Z2 direction is downward. 1A is a view of the glass manufacturing apparatus 1 viewed from the width direction Y, and FIG. 1B is a view of the glass manufacturing apparatus 1 viewed from the thickness direction Z. FIG.

The melting section 10 includes a melting kiln 11, a twill 12, and a lip 13. In the melting section 10, the frit is melted into the molten glass G1 in the melting furnace 11, and the molten glass is supplied to the forming section 20 by moving the tweel 12 in the vertical direction Z with respect to the lip 13, which is the flow path of the molten glass G1. Adjust the amount of glass G1.

The forming section 20 includes a molten metal bath (float bath) 21, a molten metal 22 stored in the molten metal bath 21, a plurality of top rolls 23, and a heater 24. In the shaping section 20, the molten glass G1 continuously supplied from the melting section 10 is gradually cooled while being flowed in the traveling direction X, and shaped into a glass ribbon G2. That is, the molten glass G1 is poured out in the form of a glass ribbon onto the molten metal surface of the molten metal bath 21 (on the surface of the molten metal 22), and floats on the molten metal surface in the traveling direction X (downstream direction X2). The glass ribbon G2 is formed by moving forward toward the glass ribbon G2.

A molten metal 22 such as tin is stored in the molten metal bath 21 . Molten glass G1 is continuously fed onto the surface of molten metal 22 via tweel 12 and lip 13 .

The molten metal bath 21 has an upstream wall 25 arranged on the upstream side, a downstream wall 26 arranged on the downstream side, and two side walls 27 , 27 connecting the upstream wall 25 and the downstream wall 26 . The two side walls 27, 27 each comprise a shoulder 27A which reduces the width (dimension in the width direction Y) of the molten metal bath 21 in the direction X of travel of the glass ribbon G2. That is, the side wall 27 includes a first wall 27B that connects to the upstream wall 25 and extends linearly in the downstream direction X2, and a first wall 27B that connects to the first wall 27B and extends inward in the width direction Y (the glass ribbon G2) in the downstream direction X2. and a second wall 27C connected to the shoulder 27A and linearly extending in the downstream direction X2. By providing the shoulder 27A in this way, the amount of the molten metal 22 stored in the molten metal bath 21 is reduced.

The distance W between the two side walls 27, 27 (the distance between the two first walls 27B, 27B) in the region upstream of the shoulder 27A of the molten metal bath 21 and the distance W in the region downstream of the shoulder 27A of the molten metal bath 21 The ratio W/N of the distance N between the two side walls 27, 27 (the distance between the two second walls 27C, 27C) is set to more than 1.0 and 1.6 or less (1.0<W/ N≤1.6). When producing convex glass, it is necessary to make the cross section of the glass ribbon G2 convex in the upstream region of the molten metal bath 21, and to make the width of the glass ribbon G2 smaller than when producing a glass plate having a constant thickness. be. Therefore, the area of the portion where the molten metal 22 is not covered with the glass ribbon G2 in the upstream region of the shoulder 27A tends to increase, and therefore the width direction Y of the glass ribbon G2 is greater than when manufacturing a glass plate with a constant thickness. Reciprocating motion (swing) to and from is likely to occur. If the ratio W/N is 1.6 or less, the area of the portion where the molten metal 22 is not covered with the glass ribbon G2 in the upstream region from the shoulder 27A is reduced, so the reciprocating motion (swing) of the glass ribbon G2 is particularly affected. The flow of the molten metal 22 in the upstream direction X1, which has an influence, is less likely to occur, and the reciprocating movement (swing) of the glass ribbon G2 in the width direction Y is less likely to occur when manufacturing the wedge glass. If the ratio W/N is greater than 1.0, the distance between the two side walls 27, 27 in the region downstream of the shoulder 27A can be narrowed, and the amount of molten metal 22 in the molten metal bath 21 can be reduced.

The position where the first wall 27B and the shoulder 27A are connected is 60% to 75% of the length L from the upstream wall 25 to the downstream wall 26 (see FIG. 1B) from the upstream wall 25 ( 0.60L to 0.75L from the upstream wall 25 in the downstream direction X2). If the position where the first wall 27B and the shoulder 27A are connected is 60% to 75% from the upstream wall 25, the molten metal 22 upstream of the shoulder 27A is covered with the glass ribbon G2 when manufacturing the wedge glass. A sufficient forming area for the glass ribbon can be ensured even when the glass having a constant thickness is produced without the area of the portion not being formed becoming too large. The position where the first wall 27B and the shoulder 27A are connected is preferably 60% or more from the upstream wall 25, more preferably 62% or more. The position where the first wall 27B and the shoulder 27A are connected is preferably 75% or less, more preferably 70% or less, even more preferably 67% or less, and particularly preferably 65% or less from the upstream wall 25 .

The position where the shoulder 27A and the second wall 27C are connected is 65% to 85% of the length L from the upstream wall 25 to the downstream wall 26 (see FIG. 1B) from the upstream wall 25 ( 0.65L to 0.85L from the upstream wall 25 in the downstream direction X2). If the position where the shoulder 27A and the second wall 27C are connected is 65% to 85% from the upstream wall 25, the molten metal 22 upstream of the shoulder 27A is covered with the glass ribbon G2 when manufacturing the wedge glass. The area of the part that is not covered should not be too large. In addition, a sufficient molding area can be secured even when manufacturing glass with a constant thickness. The position where the shoulder 27A and the second wall 27C are connected is preferably 65% or more from the upstream wall 25, more preferably 67% or more. The position where the shoulder 27A and the second wall 27C are connected is preferably 85% or less, more preferably 80% or less, even more preferably 76% or less, and particularly preferably 70% or less from the upstream wall 25.

A plurality of top rolls 23 are placed on the upper surfaces of both widthwise end portions G2B, G2B of the glass ribbon G2. That is, the plurality of top rolls 23 are in contact with the widthwise end portions G2B, G2B of the glass ribbon G2. In order to adjust the thickness of the glass ribbon G2, the peripheral speed of each top roll 23 is adjusted.

The heater 24 is arranged above the molten metal bath 21 Z1. The heaters 24 include, for example, a central heater 24A that heats the widthwise central portion G2A of the glass ribbon G2, a pair of end heaters 24B, 24B that heat both widthwise ends G2B, G2B in the width direction of the glass ribbon G2, divided into The center heater 24A and/or the end heaters 24B may be further divided in the traveling direction X and/or the width direction Y, in which case the temperature of the glass ribbon G2 is easily adjusted. In the illustrated example, two heaters 24 are arranged in the traveling direction X, divided into an upstream area from the shoulder 27A, an area including the shoulder 27A, and a downstream area from the shoulder 27A. The width of the heater 24 on the downstream side is set shorter than the width of the heater 24 on the upstream side in accordance with the relationship between the distance W and the distance N.

The slow cooling section 30 includes a slow cooling chamber 31 and transport rolls 32 . In the slow cooling section 30 , the glass ribbon G<b>2 molded in the molding section 20 is slowly cooled while being continuously transported by the transport rolls 32 arranged in the slow cooling chamber 31 . Further, by adjusting the peripheral speed of the transport roll 32, the traveling speed of the glass ribbon G2 in the forming section 20 and the slow cooling section 30 can be adjusted. Here, since the top roll 23 was placed on the upper surface of both width direction end portions G2B and G2B of the glass ribbon G2 in the molding portion 20, the portions of the width direction end portions G2B and G2B of the glass ribbon G2 on which the top roll 23 was placed Distortion occurs in the vicinity. The glass ribbon G2 is pulled out from the slow cooling section 30, and both ends of the glass ribbon G2 distorted by the top roll 23 are cut and removed by a cutting machine. Glass, which is a product, is obtained by cutting.

Next, the glass manufactured by the manufacturing method (that is, the float plate glass manufacturing method) according to one embodiment of the present invention will be described.

FIG. 2A is a cross-sectional view in the width direction of glass manufactured by a manufacturing method according to an embodiment of the present invention, and FIG. It is a wedge-shaped glass obtained by FIG. 3A is a plan view of a windshield using glass manufactured by a manufacturing method according to an embodiment of the present invention, and FIG. 3(C) is a cross-sectional view of the windshield of FIG. 3(A) taken along line CC of FIG. 3(A).

The plate glass manufactured by the manufacturing method according to one embodiment of the present invention is a convex glass 100 that becomes thicker from both ends in the width direction Y toward the center, as shown in FIG. 2(A). By cutting this convex glass 100 at a predetermined position (for example, portion A in FIG. 2(A)), wedge-shaped glass 200 whose other end is thicker than one end in the width direction Y as shown in FIG. 2(B) can be obtained. can be obtained. According to the manufacturing method of the present invention, since the reciprocating movement (swing) of the glass ribbon G2 in the width direction Y can be suppressed, the wedge-shaped glass 200 obtained by cutting the convex glass 100 (plate glass) formed from the glass ribbon G2. variation in the wedge angle β can be suppressed. Here, the convex glass 100 only needs to be thicker from both ends toward the center in the width direction Y, and both surfaces may be convex, one surface being flat and the other surface being convex. There may be.

The wedge-shaped glass 200 is preferably used for windshields 300, 400 of automobiles having a HUD, as shown in FIGS. 3(A) to 3(C), for example. In this way, by using the wedge-shaped glass 200 for the windshields 300 and 400, a double image is generated when viewed from the driver without using a special intermediate film (for example, an intermediate film having a wedge-shaped cross section). can be suppressed.

The application of the wedge-shaped glass 200 is not limited to the windshield of an automobile, but may be the window glass of a train, or the windshield for guarding the front of the driver of a motorcycle. It may be glass. Further, the application of the wedge-shaped glass 200 is not limited to information display glass for vehicles, and can be used for various other information display glasses. Furthermore, it can be used in various devices that utilize continuous changes in transmission characteristics for purposes other than information display.

The windshield 300 shown in FIG. 3(B) is a laminated glass manufactured by sandwiching an intermediate film 303 between a wedge-shaped glass 301 and a wedge-shaped glass 302 and laminating and press-bonding them.

As another form of windshield, one of the two glasses to be combined may be a glass of constant thickness. As shown in FIG. 3(C), the windshield 400 is a laminated glass manufactured by sandwiching an intermediate film 403 between a wedge-shaped glass 401 and a glass 402 having a constant thickness, and laminating and press-bonding them.

Next, a method for manufacturing plate glass according to one embodiment of the present invention will be described.
When manufacturing the convex glass 100 having a convex cross section in the width direction Y perpendicular to the traveling direction X of the glass ribbon by the method for manufacturing a plate glass according to an embodiment of the present invention, the glass is melted in the melting section 10. A glass ribbon G2 formed by continuously supplying the molten glass G1 onto the molten metal 22 is heated in the upstream region of the molten metal bath 21 at both widthwise end portions G2B and G2B more strongly than the widthwise central portion G2A. By heating both the width direction end portions G2B and G2B more strongly than the width direction center portion G2A of the glass ribbon G2, the viscosity of the width direction end portions G2B and G2B of the glass ribbon G2 is less likely to rise than the width direction center portion G2A. . As a result, the width direction end portions G2B, G2B of the glass ribbon G2 are likely to be thin, and the width direction center portion G2A is likely to be thick.

Further, in manufacturing the convex glass in the normal float plate glass manufacturing apparatus 1 described above, the center heater 24A arranged at the center in the width direction in the upstream area of the molten metal bath 21 is not substantially used, Heating is preferably performed only by the end heaters 24B arranged at both ends in the direction. Here, the “upstream region” means the upstream 70% range near the melting furnace 11 in the molten metal bath 21 . Further, "substantially not using the central heater 24A" means that the output of the central heater 24A is less than ¹ kw/m2. By heating only with the end heater 24B without substantially using the center heater 24A, the viscosity of the width direction both end portions G2B, G2B of the glass ribbon is less likely to increase than the width direction center portion G2A. The widthwise end portions G2B, G2B are thin, and the widthwise central portion G2A tends to be thick. The output of the center heater 24A may be 0 kw/ ^m2 . Moreover, you may cool the width direction center part G2A.

In the "downstream area", which is the downstream 30% range near the slow cooling chamber 31 in the molten metal bath 21, the central heater 24A may heat the glass ribbon width direction central portion G2A.

Further, it is preferable to heat the glass ribbon G2 on the surface of the molten metal so that the cooling rate of the width direction end portions G2B, G2B is 6.1°C/m or less. Here, the “cooling rate” represents the amount of decrease in temperature when the glass ribbon G2 advances 1 m in the traveling direction X in the molten metal bath 21 . If the cooling rate of the widthwise end portions G2B, G2B of the glass ribbon G2 is 6.1° C./m or less, the viscosity of the widthwise end portions G2B, G2B is less likely to increase, and the widthwise end portions G2B, G2B are thin. , the widthwise central portion G2A tends to be thick. The cooling rate of the widthwise end portions G2B, G2B is more preferably 6.0° C./m or less, further preferably 5.9° C./m or less. In this specification, when describing the cooling rate of the end of the glass ribbon G2 in the width direction, the end indicates a position 50 mm from the end of the glass ribbon G2 to the center in the width direction.

On the other hand, it is preferable to heat both ends G2B, G2B in the width direction of the glass ribbon G2 so that the cooling rate is 3.0°C/m or more. If the cooling rate of the widthwise end portions G2B, G2B is 3.0° C./m or more, the glass ribbon G2 is sufficiently cooled easily. The cooling rate of both ends G2B, G2B in the width direction may be 4.0° C./m or more, or may be 5.0° C./m or more.

It is preferable that the cooling rate of the widthwise end portions G2B, G2B of the glass ribbon G2 is slower than the cooling rate of the widthwise central portion G2A of the glass ribbon G2. If the cooling rate of the width direction both ends G2B, G2B is slower than the cooling rate of the width direction center part G2A, the viscosity of both ends becomes difficult to increase, the width direction both ends G2B, G2B are thin, and the width direction center part G2A is thin. tends to be thick.

It is preferable that the cooling rate of the widthwise end portions G2B, G2B of the glass ribbon G2 is slower than the cooling rate of the widthwise central portion G2A of the glass ribbon G2 by 0.3°C/m or more. If the rate is slower by 0.3° C./m or more, the viscosity at both ends G2B and G2B in the width direction is less likely to increase, and both ends G2B and G2B in the width direction tend to be thinner and the central portion G2A in the width direction tends to be thicker. The cooling rate of the widthwise end portions G2B, G2B may be slower than the cooling rate of the widthwise central portion G2A by 0.4° C./m or more, or may be slower by 0.5° C./m or more.

Further, the distance between the position where the viscosity of the glass ribbon G2 on both width direction ends G2B, G2B on the surface of the molten metal is 10 ^4.9 (dPa·sec) and the position where the viscosity is 10 ^6.1 (dPa·sec) is , 15 m or more. If it is 15 m or more, the viscosity of the widthwise end portions G2B, G2B is less likely to increase, the widthwise end portions G2B, G2B tend to be thin, and the widthwise center portion G2A tends to be thick. The distance is more preferably 16 m or longer, and even more preferably 16.5 m or longer. Here, the viscosity of the glass ribbon G2 is calculated by measuring the temperature of the glass ribbon G2 with a radiation thermometer and using the viscosity curve (Fulcher formula) of the glass from the measured temperature. In addition, in this specification, when the viscosity at the end of the glass ribbon G2 in the width direction is described, the end indicates a position 50 mm from the end of the glass ribbon G2 to the center in the width direction, as described above.

On the other hand, the distance between the position where the viscosity of the glass ribbon G2 in the width direction both ends G2B, G2B on the surface of the molten metal is 10 ^4.9 (dPa·sec) and the position where the viscosity is 10 ^6.1 (dPa·sec) is , 30 m or less. If it is 30 m or less, the glass ribbon will be sufficiently cooled easily. The distance may be 25m or less, or may be 20m or less.

Further, a top roll 23 is placed on the upper surface of the width direction end portions G2B, G2B of the glass ribbon G2 heated by the heater 24, and the glass ribbon is formed into a desired width, thickness and shape by the action of the top roll 23. to mold. At this time, it is preferable that the circumferential speed of each top roll 23 is adjusted so that the speed of the top roll 23 becomes faster as it is located on the downstream side. In addition, the peripheral speed when manufacturing the convex glass 100 is such that the peripheral speed of the upstream top roll 23A in the traveling direction X of the glass ribbon G2 is slower than the peripheral speed of the downstream top roll 23B. 23 is preferably rotated. Further, by heating only with the end heaters 24B without substantially using the center heater 24A, the viscosity of the width direction both end portions G2B, G2B of the glass ribbon is less likely to rise than the width direction center portion G2A. As a result, when widening the width of the glass ribbon G2 that spreads to both sides of the rotation shaft of the upstream top roll 23A, the widthwise end portions G2B, G2B of the glass ribbon G2 can be made thinner, and the widthwise central portion G2A can be made thicker.

The upstream top roll 23A refers to the top roll 23 closer to the melting kiln 11 among a plurality of pairs of top rolls 23 arranged at both ends G2B, G2B in the width direction of the glass ribbon G2 traveling in the molten metal bath 21. , may be only one pair closest to the melting kiln 11, two pairs close to the melting kiln 11, or three pairs. Two pairs are preferred. In particular, the pair of top rolls 23 closest to the melting kiln 11 is called the most upstream top roll 23A. The downstream top roll 23B refers to the top roll closest to the slow cooling chamber 31 among the top rolls 23, and may be only one pair closest to the slow cooling chamber 31, or two pairs close to the slow cooling chamber 31. , may be three pairs. In particular, the pair of top rolls 23 closest to the slow cooling chamber 31 is called the most downstream top roll 23B. 1A and 1B show two pairs of upstream top rolls 23A and two pairs of downstream top rolls 23B.

It is preferable that 7 to 15 pairs of top rolls 23 are arranged at both ends G2B, G2B in the width direction of the glass ribbon G2. With 7 to 15 pairs, it becomes easy to adjust the thickness of the glass ribbon G2 to a predetermined thickness. More preferably, 8 to 13 pairs of top rolls 23 are arranged. FIGS. 1A and 1B show an example in which nine pairs of top rolls 23 are arranged at both ends G2B and G2B in the width direction of the glass ribbon G2.

Further, in a region where the viscosity of the width direction end portions G2B, G2B of the glass ribbon G2 on the molten metal surface is 10 ^5.3 (dPa·sec) or less (hereinafter referred to as a low viscosity region), the width direction end portions G2B, The top rolls 23 arranged in G2B may be 8 pairs or less, 7 pairs or less, 6 pairs or less, 5 pairs or less, or 3 pairs or less. There may be.

On the other hand, in a region (hereinafter referred to as a high-viscosity region) in which the viscosity of the width direction end portions G2B, G2B of the glass ribbon G2 on the surface of the molten metal exceeds 10 ^5.3 (dPa·sec), the width direction end portions G2B, The top rolls 23 arranged in G2B may be 10 pairs or less, 8 pairs or less, 6 pairs or less, 4 pairs or less, or 2 pairs or less. There may be one pair or less.

The upstream top roll 23A may be arranged in the low viscosity region, and the downstream top roll 23B may be arranged in the high viscosity region.

In the top roll 23 arranged in the region (low viscosity region) where the viscosity of the width direction end portions G2B, G2B of the glass ribbon G2 on the surface of the molten metal is 10 ^5.3 (dPa·sec) or less (low viscosity region), in the traveling direction X The difference in circumferential speed between at least one pair of adjacent top rolls 23, 23 is preferably 35 (m/hour) or more. If it is 35 (m/h) or more, the glass ribbon G2 is pulled in the downstream direction X2 in the region where the viscosity of the glass ribbon G2 is 10 ^5.3 (dPa·sec) or less, and the width direction both ends G2B, G2B can be made thinner. As a result, the widthwise end portions G2B and G2B are thin, and the widthwise center portion G2A is thick, so that the sheet glass having a convex cross section in the widthwise direction Y is manufactured.

^At least one set of top rolls 23, 23 may be 40 (m/h) or more, 45 (m/h) or more, or 50 (m/h) or more.

On the other hand, in the top roll 23 arranged in the region (low viscosity region) where the viscosity of the width direction end portions G2B, G2B of the glass ribbon G2 on the surface of the molten metal is 10 ^5.3 (dPa·sec) or less, The difference in peripheral speed between at least one pair of top rolls 23, 23 adjacent to each other in X is preferably 100 (m/hour) or less. If it is 100 (m/h) or less, it is easy to adjust the thickness of the glass ribbon G2. It may be 80 (m/h) or less, or 60 (m/h) or less.

The peripheral speed R of the most upstream top roll 23A is preferably 120 (m/h) or less. If it is 120 (m/h) or less, the width of the glass ribbon G2 that spreads to both sides of the rotating shaft of the pair of top rolls 23A on the most upstream side can be widened. As a result, the widthwise end portions G2B, G2B of the glass ribbon G2 tend to be thin, and the widthwise central portion G2A tends to be thick. The peripheral speed R of the most upstream top roll 23A may be 110 (m/h) or less, 100 (m/h) or less, or 90 (m/h) or less. , 80 (m/h) or less, 70 (m/h) or less, or 60 (m/h) or less.

On the other hand, the peripheral speed R of the most upstream top roll 23A is preferably 30 (m/h) or more. If it is 30 (m/hour) or more, it is easy to adjust the thickness of the glass ribbon G2. The peripheral speed R of the most upstream top roll 23A may be 40 (m/hour) or more, or may be 50 (m/hour) or more.

FIG. 4 is an enlarged view of the top roll 23. FIG. As shown in FIG. 4, in order to adjust the thickness of the glass ribbon G2, the angle D between the traveling direction X of the glass ribbon G2 and the rotation axis direction J of the top roll 23 may be adjusted. By adjusting the angle D of the most upstream top roll 23A to 75° to 90° and adjusting the angle D of the most downstream top roll 23B to 90° to 105°, the glass ribbon G2 It is easy to reduce the thickness of the width direction both ends G2B and G2B. The angle D of the most upstream top roll 23A is more preferably 80° to 85°, more preferably 81° to 84°. The angle D of the most downstream top roll 23B is more preferably 95° to 100°, more preferably 96 to 99°.

In addition, by adjusting the traveling speed of the glass ribbon G2 in the molding section 20 and the slow cooling section 30, it becomes easy to spread the glass ribbon G2 in the width direction Y upstream of the molten metal bath 21, and the width of the glass ribbon G2 is reduced. The thickness of both direction end portions G2B, G2B can be reduced.

The traveling speed of the glass ribbon G2 in the molding section 20 and the slow cooling section 30 may be 200 to 1500 (m/hour). By setting the traveling speed of the glass ribbon G2 in the molding section 20 and the slow cooling section 30 to 200 to 1500 (m/h), it becomes easy to spread the glass ribbon G2 in the width direction Y upstream of the molten metal bath 21. , the width direction end portions G2B, G2B of the glass ribbon G2 can be easily reduced in thickness. The traveling speed of G2 of the glass ribbon may be 500 (m/h) or more, 600 (m/h) or more, or 700 (m/h) or more. On the other hand, the traveling speed of G2 of the glass ribbon may be 1300 (m/h) or less, 1100 (m/h) or less, or 900 (m/h) or less.

The difference (TM) between the maximum value T and the minimum value M of the thickness of the plate glass manufactured by the manufacturing method according to one embodiment of the present invention is preferably 0.1 mm or more. If the difference (TM) is 0.1 mm or more, it is possible to reduce the occurrence of double images when used as information display glass even when the glass is installed in a vehicle with a large angle of the windshield with respect to the horizontal plane. . Here, the difference (TM) between the maximum value T and the minimum value M of the thickness of the plate glass is obtained by cutting both ends in the width direction Y of the glass ribbon G2 distorted by the top roll 23 with a cutting machine. It is the difference between the maximum and minimum values of the thickness of the convex glass 100 obtained by removing the convex glass. The difference (TM) may be 0.2 mm or more, 0.3 mm or more, 0.4 mm or more, or 0.5 mm or more. On the other hand, the difference (TM) may be 1.5 mm or less. If the thickness is 1.5 mm or less, distortion of a reflected image can be suppressed when the glass is used as information display glass even if the glass is installed in a vehicle with a small angle of the windshield with respect to the horizontal plane. The difference (TM) may be 1.3 mm or less, 1.2 mm or less, 1.1 mm or less, or 1.0 mm or less. When this plate glass is used, for example, as a windshield of an automobile, the maximum value T and the minimum value of the optimum thickness of the plate glass are determined depending on the angle at which the windshield is attached and the angle and position at which the irradiator for displaying information is attached. The difference (TM) from M is selected.

In the sheet glass manufactured by the manufacturing method according to one embodiment of the present invention, the maximum height Rz of the roughness curve at the standard length of 25 mm specified in JIS B 0601:2001 on the main surface of the sheet glass is 0.3 μm or less. preferable. If the Rz of the main surface of the plate glass is 0.3 μm or less, for example, when the plate glass is used as information display glass, the scenery seen through the glass can be viewed without distortion. In addition, the reflected image is less likely to be distorted when information is displayed on the plate glass. Here, the roughness curve is represented by a shape waveform. Rz is more preferably 0.25 μm or less, still more preferably 0.2 μm or less, particularly preferably 0.18 μm or less, and most preferably 0.16 μm or less. The Rz of the main surface of the sheet glass can be reduced by slowing down the traveling speed V of the glass ribbon G2 in the slow cooling section 30 . Here, the plate glass main surface means the surface where the glass ribbon G2 was in contact with the molten metal 22 in the molten metal bath 21 (hereinafter referred to as the molten metal contact surface), and the molten metal 22 facing the molten metal contact surface. This is the surface that was not in contact (hereinafter referred to as the molten metal non-contact surface).

As shown in FIG. 1B, the distance W between the two side walls 27, 27 (the distance between the two first walls 27B, 27B) in the upstream region of the shoulder 27A of the molten metal bath 21 and the distance W between the two first walls 27B, 27B The ratio W/N of the distance N between the two side walls 27, 27 (the distance between the two second walls 27C, 27C) in the downstream region of the shoulder 27A of 21 is more than 1.0 and 1.6 or less. is preferred (1.0<W/N≤1.6). If W/N is 1.6 or less, the area of the portion where the molten metal 22 is not covered with the glass ribbon G2 in the upstream region from the shoulder 27A decreases, so that the molten metal 22 flows in the upstream direction X1. reciprocating movement (swing) in the width direction Y of the glass ribbon G2 is less likely to occur. Therefore, the variation in the wedge angle β of the wedge-shaped glass 200 (see FIG. 2(B)) obtained by cutting the convex glass 100 (see FIG. 2(A)) obtained by the manufacturing method of the sheet glass of the present embodiment can be suppressed.

If the ratio W/N exceeds 1.0, the distance between the two side walls 27, 27 in the downstream region from the shoulder 27A can be narrowed, and the amount of molten metal 22 in the molten metal bath 21 can be reduced.

The ratio W/N is more preferably 1.1 or more, even more preferably 1.3 or more. Moreover, the W/N is more preferably 1.55 or less, and even more preferably 1.50 or less.

The molten metal It is preferable that the glass ribbon G2 is heated by the heater 24 so that the viscosity of the central portion G2A in the width direction of the glass ribbon G2 on the surface becomes 10̂(4.5) (dPa·sec) or more. If the viscosity of the widthwise central portion G2A is 10̂(4.5) (dPa·sec) or more, the widthwise end portions G2B, G2B tend to be thin, and the widthwise central portion G2A tends to be thick. Therefore, the wedge angle β of the wedge-shaped glass 200 (see FIG. 2(B)) obtained by cutting the convex glass 100 (see FIG. 2(A)) obtained by the manufacturing method of the plate glass of the present embodiment is increased. can.

The viscosity of the central portion G2A in the width direction of the glass ribbon G2 on the surface of the molten metal at a position 20% from the upstream wall 25 (a position 0.2L in the downstream direction X2 from the upstream wall 25) is 10̂(5.0). (dPa·sec) or more is more preferable, and 10^(5.3) (dPa·sec) or more is even more preferable. This is because the temperature of the widthwise central portion G2A of the glass ribbon G2 is relatively lower than the temperatures of the widthwise end portions G2B, G2B, and the wedge angle β can be increased.

The molten metal It is preferable that the glass ribbon G2 is heated by the heater 24 so that the viscosity of the widthwise central portion G2A of the glass ribbon G2 on the surface becomes 10̂(6.0) (dPa·sec) or less. If the viscosity of the glass ribbon G2 is too high, it becomes difficult for the top roll 23 to enter the glass ribbon G2, making it difficult to control the position of the glass ribbon G2. put away. In this embodiment, since the viscosity of the widthwise central portion G2A is 10̂(6.0) (dPa·sec) or less, the occurrence of swing can be suppressed.

The viscosity of the central portion G2A in the width direction of the glass ribbon G2 on the surface of the molten metal at a position 20% from the upstream wall 25 (a position 0.2L in the downstream direction X2 from the upstream wall 25) is 10̂(5.8). (dPa·sec) or less is more preferable, and 10̂(5.6) (dPa·sec) or less is even more preferable. This is because the lower the viscosity of the glass ribbon G2, the easier it is for the top roll 23 to enter the glass ribbon G2, thereby suppressing the occurrence of swing.

The molten metal It is preferable that the difference (I−K) between the temperature I of the central portion G2A in the width direction of the glass ribbon G2 on the surface and the temperature K of both ends in the width direction of the molten metal 22 is 62° C. or less. If the temperature difference (I−K) is 62° C. or less, the difference in viscosity between the width direction end portions and the width direction center portion of the glass ribbon G2 is small, and the width direction end portions G2B and G2B are thin and the width direction is thin. The central portion G2A tends to be thick. The temperature difference (I−K) is more preferably 50° C. or less, more preferably 40° C. or less. The lower limit of the temperature difference (I−K) may be 0° C. or higher, 10° C. or higher, or 15° C. or higher in order to suppress excessive output to the heater 24 . The temperature K at both ends in the width direction of the molten metal 22 means the temperature at positions 50 mm from the two side walls 27 of the molten metal bath 21 to the center in the width direction.

The molten metal It is preferable that the glass ribbon G2 is heated by the heater 24 so that the viscosity of the central portion G2A in the width direction of the glass ribbon G2 on the surface becomes 10̂(4.7) (dPa·sec) or more. If the viscosity of the widthwise central portion G2A is 10̂(4.7) (dPa·sec) or more, the widthwise end portions G2B and G2B tend to be thin, and the widthwise central portion G2A tends to be thick. Therefore, the wedge angle β of the wedge-shaped glass 200 (see FIG. 2(B)) obtained by cutting the convex glass 100 (see FIG. 2(A)) obtained by the manufacturing method of the plate glass of the present embodiment is increased. can.

The viscosity of the central portion G2A in the width direction of the glass ribbon G2 on the surface of the molten metal at a position 32% from the upstream wall 25 (a position 0.32L in the downstream direction X2 from the upstream wall 25) is 10̂(5.0). (dPa·sec) or more is more preferable, and 10^(5.3) (dPa·sec) or more is even more preferable. This is because the temperature of the widthwise central portion G2A of the glass ribbon G2 is lower than the temperature of the widthwise end portions G2B, G2B, and the wedge angle β can be increased.

The molten metal It is preferable that the glass ribbon G2 is heated by the heater 24 so that the viscosity of the central portion G2A in the width direction of the glass ribbon G2 on the surface becomes 10̂(6.3) (dPa·sec) or less. If the viscosity of the glass ribbon G2 is too high, it becomes difficult for the top roll 23 to enter the glass ribbon G2, making it difficult to control the position of the glass ribbon G2. put away. In this embodiment, since the viscosity of the widthwise central portion G2A is 10̂(6.3) (dPa·sec) or less, the occurrence of swing can be suppressed.

The viscosity of the central portion G2A in the width direction of the glass ribbon G2 on the surface of the molten metal at a position 32% from the upstream wall 25 (a position 0.32L in the downstream direction X2 from the upstream wall 25) is 10̂(6.0). (dPa·sec) or less is more preferable, and 10̂(5.8) (dPa·sec) or less is even more preferable. This is because the lower the viscosity of the glass ribbon G2, the easier it is for the top roll 23 to enter the glass ribbon G2, thereby suppressing the occurrence of swing.

The maximum width c in the width direction Y of the glass ribbon G2 (located between the upstream wall 25 and the downstream wall 26) in the molten metal bath 21 and the length in the width direction Y of the glass ribbon G2 at the most downstream side of the molten metal bath 21 The ratio c/b of b is preferably 1.4 to 2.2 (1.4≤c/b≤2.2). If the ratio c/b is 1.4 to 2.2, the area of the portion where the molten metal 22 is not covered with the glass ribbon G2 decreases, so that the molten metal 22 is less likely to flow in the upstream direction X1. , reciprocating movement (swing) in the width direction Y of the glass ribbon G2 is less likely to occur.

The ratio c/b is more preferably 1.6 or more, and even more preferably 1.7 or more. The ratio c/b is more preferably 2.1 or less, even more preferably 2.0 or less. The length in the width direction of the glass ribbon G2 in the molten metal bath 21 is obtained from the image obtained by photographing the glass ribbon G2 with a camera and the position of the top roll.

A width a (not shown) of the glass ribbon G2 at a position 35% from the upstream wall 25 (0.35 L in the downstream direction X2 from the upstream wall 25) with respect to the length L from the upstream wall 25 to the downstream wall 26; , the length b (not shown) in the width direction Y of the glass ribbon G2 at the most downstream of the molten metal bath 21, and the ratio a/b is preferably 1.0 to 1.9 (1.0 ≤ a /b≤1.9). When the ratio a/b is 1.0 to 1.9, the area of the portion where the molten metal 22 is not covered with the glass ribbon G2 is reduced, so that the molten metal 22 is less likely to flow in the upstream direction X1. , reciprocating movement (swing) in the width direction Y of the glass ribbon G2 is less likely to occur.

The ratio a/b is more preferably 1.3 or more, more preferably 1.4 or more. The ratio a/b is more preferably 1.8 or less, even more preferably 1.7 or less, and particularly preferably 1.6 or less.

The length of the width direction Y of the glass ribbon G2 at a position 20% from the upstream wall 25 with respect to the length L from the upstream wall 25 to the downstream wall 26 (position of 0.2 L in the downstream direction X2 from the upstream wall 25) It is preferable that the ratio A/B between A (not shown) and the length B (not shown) in the width direction Y of the molten metal surface not covered with the glass ribbon G2 is 4 to 11 (4 ≤ A/B < 11). The length B is the length in the width direction Y of the molten metal on both sides in the width direction of the glass ribbon G2 at a position 20% from the upstream wall 25 (a position 0.2L in the downstream direction X2 from the upstream wall 25). Thus, the length B is the distance W between the two side walls 27, 27 in the region upstream of the shoulder 27A of the molten metal bath 21 (see FIG. 1B) minus the length A (B= WA). Thus, since the ratio A/B is set to 4 to 11, the molten metal 22 is covered with the glass ribbon G2 in a wide range, and the flow of the molten metal 22 in the upstream direction X1 is difficult to occur, and the glass ribbon The reciprocating motion (swing) of G2 in the width direction Y can be suppressed. The length B is determined from an image obtained by photographing the molten metal surface not covered with the glass ribbon G2 with a camera.

It should be noted that if the ratio A/B is less than 4, the exposed range of the molten metal 22 is widened, and the swing of the glass ribbon G2 tends to occur. Further, when the ratio A/B is greater than 11, the width of the glass ribbon G2 becomes wider than that of the molten metal bath 21, making it difficult to control the width of the glass ribbon G2 with the top roll 23. It is preferable to manage the ratio A/B at 11 or less because it is likely to interfere with members installed at 21 . Also, the ratio A/B is more preferably 5 or more, and even more preferably 5.5 or more. The ratio A/B is more preferably 10 or less, and even more preferably 9 or less.

A wedge-shaped glass and a laminated glass are manufactured from the sheet glass manufactured by the method for manufacturing the sheet glass described above.
A method for manufacturing wedge-shaped glass and laminated glass according to an embodiment of the present invention will be described with reference to FIGS. Here, a method for manufacturing laminated glass used for windshields of vehicles will be described as an example.

A method for manufacturing wedge-shaped glass according to an embodiment of the present invention includes a step of obtaining wedge-shaped glass 200 by cutting convex-shaped glass plate 100 obtained by the method for manufacturing plate glass described above. A method for manufacturing laminated glass according to an embodiment of the present invention includes a step of cutting convex-shaped sheet glass 100 obtained by the method for manufacturing sheet glass described above to obtain wedge-shaped glass 200, and separating wedge-shaped glass 200 from another sheet glass. and a step of stacking and press-bonding via an intermediate film.

First, the convex glass 100 that becomes thicker toward the central portion in the width direction is obtained by the method for manufacturing the sheet glass described above (see FIG. 2(A)). By cutting the convex glass 100 at a predetermined position (A portion in the drawing), a wedge-shaped glass 200 having a widthwise one end thicker than the other end is obtained (see FIG. 2(B)). Although the cutting method is not limited, for example, the convex glass 100 is cut out by forming a scribe line in the shape of a window glass with a cutter on the convex glass 100 and breaking it to obtain the wedge-shaped glass 200 . The wedge-shaped glass 200 is chamfered on the periphery.

Next, a pair of glass sheets, that is, the wedge-shaped glass 200 and another sheet glass are bent by a method such as gravity bending while being superimposed with a release agent interposed therebetween. A pair of plate glasses are bent in a softened state by being heated in a furnace, and then slowly cooled. The bending method is not limited to gravity bending, and a pair of plate glasses may be formed by press bending, or may be bent one by one without overlapping.

Next, the wedge-shaped glass 200 and another plate glass are laminated via an intermediate film and pressed together to obtain a laminated glass. The other sheet glass may be wedge-shaped glass 200 or sheet glass with a constant thickness. A plate glass of constant thickness is obtained by a known method and cut by the cutting method described above. The laminated glass 300 (see FIGS. 3A and 3B), in which the other sheet glass is the wedge-shaped glass 200, is installed in a vehicle with a large angle of the windshield with respect to the horizontal plane, and when information is displayed, the reflection Image is less distorted. The laminated glass 400 (see FIG. 3(C)), in which the other sheet glass is a sheet glass with a constant thickness, allows the scenery seen through the windshield to be viewed without distortion. Materials for the intermediate film include, for example, polyvinyl butyral.

When crimping, first, the pair of glass sheets and the intermediate film are heated and bonded by performing a degassing process to remove the air between the pair of glass sheets and the intermediate film. For example, air can be removed by putting a laminated body of a pair of plate glasses and an intermediate film in a rubber bag and heating it under reduced pressure. Alternatively, the nipper top roll method or the rubber channel method may be used. Next, the laminated body of the pair of plate glasses and the intermediate film is subjected to pressure treatment in an autoclave to heat and bond the pair of plate glasses and the intermediate film. For example, polyvinyl butyral (PVB) and ethylene vinyl acetate (EVA) are used as the intermediate film.

Next, a wedge-shaped glass according to one embodiment of the present invention will be described.
5A and 5B are diagrams showing a wedge-shaped glass 500 according to an embodiment of the present invention, FIG. 5A being a plan view and FIG. 5B being a cross-sectional view.

The wedge-shaped glass 500 according to one embodiment of the present invention is obtained, for example, by cutting the plate glass obtained by the method for manufacturing the plate glass described above. Although the cutting method is not limited, for example, the wedge-shaped glass 500 according to one embodiment of the present invention can be obtained by forming a scribe line in the shape of a window glass on the plate glass with a cutter and breaking it.

When the wedge-shaped glass 500 according to one embodiment of the present invention is used as a windshield of a vehicle, the wedge-shaped glass 500 is attached to the vehicle such that the side 502 having the smallest thickness is positioned downward, and the thickness of the windshield is Information is displayed at the lower part of the screen.

The wedge-shaped glass 500 according to one embodiment of the present invention is characterized in that at least one main surface is a convex surface 507 . Since the main surface is the convex surface 507, the reflected image is less likely to be distorted when information is displayed on the plate glass. In addition, compared to the case where the main surface is concave, the thickness of the upper part of the windshield where information is not displayed is thinner, the weight of the windshield can be reduced, and the fuel efficiency of the vehicle is improved. The position where the information is displayed on the windshield is not limited to the lower part, and may be the upper part, the left side, the right side, or the center. The plate glass is attached so that the thickness of the position where the information is to be displayed is thin. Regardless of the position where the information is displayed, if the main surface is the convex surface 507, the thickness of the portion where the information is not displayed can be reduced compared to the case where the main surface is concave, and the weight of the windshield can be reduced. .

The wedge-shaped glass 500 according to one embodiment of the present invention is preferably rectangular. If the wedge-shaped glass 500 is rectangular, handling such as transportation is easy. Here, the rectangle is not limited to an exact rectangle, and may have curved sides. Further, the angle of the corner is not limited to 90°, and may be 80 to 100°.

The wedge-shaped glass 500 according to one embodiment of the present invention may have notches and may have arcuate corners.

The wedge-shaped glass 500 according to one embodiment of the present invention has a line segment 503 that passes through the center of gravity G of the convex surface 507 and connects two opposite sides of the four sides 501, 502, 508, and 509 of the convex surface 507 at the shortest distance. Among the intersection points 504 and 505 between the line segment 503 and the side of the convex surface 507, the point at which the thickness of the wedge-shaped glass 500 in the vertical direction is smaller when the wedge-shaped glass 500 is placed on a horizontal surface is designated as the first point 504. and a second point 506 is a point on the convex surface 507 which is 2/5 of the length of the line segment 503 from the first point 504. Then, the first point 504 and the second point The angle α between the straight line H connecting the point 506 and the horizontal plane is preferably 0.020° to 0.050°. The thickness of the plate glass is determined by, for example, a laser displacement gauge, microgauge, ultrasonic thickness gauge, etc., and the angle α is calculated from the measured thickness.

When the windshield is installed in a vehicle with a small angle with respect to the horizontal plane of the windshield, it is preferable that the angle α of the wedge-shaped glass 500 is small because the double image of the projected image projected on the windshield is reduced. On the other hand, when the windshield is installed in a vehicle with a large angle with respect to the horizontal plane of the windshield, a large angle α of the wedge-shaped glass 500 is preferable because the double image of the projected image projected on the windshield is reduced.

The wedge-shaped glass 500 according to one embodiment of the present invention has an angle α of 0.020° or more, so that when the windshield is attached to a vehicle having a large angle with respect to the horizontal plane and information is displayed on the plate glass, double images can be obtained. is reduced. The angle α may be 0.023° or more, 0.025° or more, 0.030° or more, or 0.033° or more. In addition, since the angle α is 0.050° or less, double images are reduced when information is displayed on the plate glass even when the windshield is attached to a vehicle having a small angle with respect to the horizontal plane. The angle α may be 0.04° or less. The optimum angle α is selected depending on the angle at which the windshield is attached and the angle and position at which the illuminator for displaying information is attached.

In the wedge-shaped glass 500 according to one embodiment of the present invention, it is preferable that the maximum height Rz of the roughness curve at the reference length of 25 mm defined in JIS B 0601:2001 of the main surface of the wedge-shaped glass 500 is 0.3 μm or less. . Since Rz is 0.3 μm or less, the scenery seen through the wedge-shaped glass 500 can be seen without distortion. In addition, the reflected image is less likely to be distorted when information is displayed on the plate glass.

In the wedge-shaped glass 500 according to one embodiment of the present invention, the difference (TM) between the maximum value T and the minimum value M of the thickness of the wedge-shaped glass 500 is preferably 0.1 mm or more. Since the difference (TM) between the maximum value T and the minimum value M of the thickness of the plate glass is 0.1 mm or more, it is installed in a vehicle where the angle of the windshield with respect to the horizontal plane is large, and when used as information display glass. It is possible to suppress the occurrence of double images. On the other hand, the difference (TM) may be 1.5 mm or less. If it is 1.5 mm or less, it is possible to suppress the occurrence of double images when it is installed in a vehicle in which the angle of the windshield with respect to the horizontal plane is small and used as information display glass. The difference (TM) may be 1.3 mm or less, 1.2 mm or less, 1.1 mm or less, or 1.0 mm or less.

The wedge-shaped glass 500 according to one embodiment of the present invention preferably has a ratio T/M between the maximum thickness T and the minimum thickness M of the wedge-shaped glass 500 of 1.10 to 1.40. If the T/M is 1.10 or more, it is possible to suppress the occurrence of a double image when information is displayed on the plate glass by installing the windshield on a vehicle having a large angle with respect to the horizontal plane. The ratio T/M may be 1.12 or more, 1.15 or more, 1.20 or more, or 1.25 or more. Further, if the ratio T/M is 1.40 or less, it is possible to suppress generation of a reflected image when information is displayed on the plate glass even when the windshield is mounted on a vehicle having a small angle with respect to the horizontal plane. The ratio T/M may be 1.35 or less, 1.30 or less, or 1.28 or less. The optimal ratio T/M is selected depending on the angle at which the windshield is installed and the angle and position of the illuminator for displaying information.

The wedge-shaped glass 500 according to one embodiment of the present invention preferably has short sides 508 and 509 of 600 mm or more. If it is 600 mm or more, it can be used for large vehicles. Also, it is installed in a vehicle in which the angle of the windshield with respect to the horizontal plane is small. The sheet glass may be 800 mm or more, 1000 mm or more, 1200 mm or more, or 1400 mm or more.

Wedge glass 500 can be used to produce laminated glass.
A method for manufacturing laminated glass according to an embodiment of the present invention includes a step of cutting sheet glass 100 to obtain wedge-shaped glass. A method for manufacturing laminated glass according to an embodiment of the present invention includes the steps of cutting the sheet glass 100 to obtain wedge-shaped glass, and laminating and press-bonding the wedge-shaped glass and another sheet glass via an intermediate film. .

First, by cutting the plate glass 100 at a predetermined position, a wedge-shaped glass is obtained in which the other end is thicker than the one end in the width direction. After that, the laminated glass is manufactured through the same steps as in the method for manufacturing laminated glass using the sheet glass manufactured by the above-described method for manufacturing sheet glass.

As described above, in the above embodiment, in the upstream region of the molten metal bath 21, the width direction end portions G2B and G2B are heated more strongly than the width direction center portion G2A of the glass ribbon, and the upstream top roll in the traveling direction F1 The plurality of top rolls 23 are rotated so that the peripheral speed of 23A is slower than the peripheral speed of the downstream top roll 23B. As a result, the viscosity of the width direction end portions G2B, G2B is less likely to rise than the width direction center portion G2A, and the width of the glass ribbon that spreads to both sides of the rotation axis of the upstream top roll can be widened. It becomes easy to spread the glass ribbon G2 in the width direction upstream of the bath 21, and the thickness of the width direction both end portions G2B and G2B of the glass ribbon G2 can be made thinner, and the width direction central portion G2A can be made thicker.

In addition, the distance W between the two side walls 27, 27 (the distance between the two first walls 27B, 27B) in the upstream region from the shoulder 27A of the molten metal bath 21 and the downstream region from the shoulder 27A of the molten metal bath 21 The ratio W/N between the two side walls 27, 27 (the distance between the two second walls 27C, 27C) is set to more than 1.0 and 1.6 or less, so the molten metal 22 Flow in the upstream direction X1 is less likely to occur, and reciprocating movement (swing) in the width direction Y of the glass ribbon G2 is less likely to occur. Therefore, it is possible to suppress the variation in the wedge angle of the wedge-shaped glass obtained by cutting the plate glass obtained by the manufacturing method of the plate glass of the present embodiment.

Next, an embodiment of the present invention will be described. Using the glass manufacturing apparatus 1 shown in FIGS. 1A and 1B, convex glasses 100 according to Examples 1 to 15 were manufactured. Examples 1-14 are working examples, and example 15 is a comparative example.

In Examples 1-15, the distance W between the two side walls 27, 27 in the upstream region of the shoulder 27A of the molten metal bath 21 (the distance between the two first walls 27B, 27B) and the shoulder 27A of the molten metal bath 21 Table 1 shows the distance N between the two side walls 27, 27 (the distance between the two second walls 27C, 27C) and their ratio W/N in the downstream region. Examples 1 to 14 satisfy the above formula "1.0<W/N≦1.6", but Example 15 did not satisfy the above formula.

In Examples 1 to 15, the position where the first wall 27B and the shoulder 27A are connected is the length L from the upstream wall 25 to the downstream wall 26 (see FIG. 1B), and the distance from the upstream wall 25 to Table 1 It was the position of the ratio shown in . Examples 1-15 met the above condition "60% to 75% from upstream wall 25".

In Examples 1 to 15, the position where the shoulder 27A and the second wall 27C are connected is the length L from the upstream wall 25 to the downstream wall 26 (see FIG. 1B), and the distance from the upstream wall 25 to the table 1 It was the position of the ratio shown in . Examples 1-15 met the above condition "65% to 85% from upstream wall 25".

In Examples 1 to 15, the position of 20% from the upstream wall 25 with respect to the length L from the upstream wall 25 to the downstream wall 26 (see FIG. 1B) (the position of 0.2L in the downstream direction X2 from the upstream wall 25) ) was as shown in Table 1 at the width direction central portion G2A of the glass ribbon G2 on the surface of the molten metal. Examples 1 to 15 satisfied the above condition "viscosity is 10̂(4.5) (dPa·sec) or more". In addition, Examples 1 to 15 satisfied the above-mentioned condition that the viscosity was 10̂(6.0) (dPa·sec) or less.

In Examples 1 to 15, the length L from the upstream wall 25 to the downstream wall 26 (see FIG. 1B) is 32% from the upstream wall 25 (0.32L from the upstream wall 25 in the downstream direction X2). ), the temperature I and the viscosity of the widthwise central portion G2A of the glass ribbon G2 on the molten metal surface were as shown in Table 1. Examples 1 to 15 satisfied the above-mentioned condition "viscosity is 10̂(4.7) (dPa·sec) or more". Further, Examples 1 to 15 satisfied the above-mentioned condition that the viscosity was 10̂(6.3) (dPa·sec) or less.

In Examples 1 to 15, the length L from the upstream wall 25 to the downstream wall 26 (see FIG. 1B) is 32% from the upstream wall 25 (0.32L from the upstream wall 25 in the downstream direction X2). ) was as shown in Table 1. Further, the difference (I−K) between temperature I and temperature K was as shown in Table 1. Examples 1 to 14 satisfied the above condition "(IK) is 62° C. or less".

In Examples 1 to 14, Table 1 shows the maximum width c in the width direction Y of the glass ribbon G2 in the molten metal bath 21, the width b at the most downstream side, and their ratio c/b. Examples 1 to 14 satisfied the above condition "1.4≤c/b≤2.2".

In Examples 1 to 14, the width a of the glass ribbon G2 at a position 35% from the upstream wall 25 with respect to the length L from the upstream wall 25 to the downstream wall 26 (a position 0.35L in the downstream direction X2 from the upstream wall 25) , the minimum width b in the width direction Y of the glass ribbon G2 in the molten metal bath 21, and their ratio a/b were as shown in Table 1. Examples 1 to 14 satisfied the above condition "1.0≤a/b≤1.9".

In Examples 1 to 14, the length L from the upstream wall 25 to the downstream wall 26 is 20% from the upstream wall 25 (0.2L in the downstream direction X2 from the upstream wall 25). The length A (not shown) in the width direction Y, the length B (not shown) in the width direction Y of the molten metal surface not covered with the glass ribbon G2, and their ratio A/B are shown in Table 1. It was as shown. Examples 1 to 14 satisfied the above condition "4≤A/B≤11".

In Examples 1 to 15, the top rolls 23 were arranged at both ends of the molten metal bath 21 in the width direction Y. The traveling speed V (m/h) of the glass ribbon G2 in the slow cooling section 30 was set as shown in Table 2.

Table 2 shows the maximum value T (mm) and minimum value M (mm) of the thickness of the sheet glass (convex glass) obtained under the above manufacturing conditions, and the width of the glass ribbon G2 in the slow cooling section 30. The thickness t, the difference (TM) (mm), and the ratio T/M of the direction center part G2A are also shown.

Table 1 shows the angles α (see FIG. 5(B)) of the convex glasses of Examples 1 to 15 obtained under the manufacturing conditions described above. In all Examples 1-14, except Example 15, the angle α was within the preferred range of 0.020° to 0.050°.

In addition, in all Examples 1 to 15, the maximum distance (swing width) moved in the width direction Y in 30 minutes at the point where the glass ribbon G2 was cut was less than 1.5 inches, which was suppressed to a small value. However, in Example 15, when the maximum distance (swing width) moved in the width direction Y in 30 minutes at the point where the glass ribbon G2 is cut is suppressed to less than 1.5 inches, the angle α becomes 0.017°, The angle α could not be 0.020° or more. In Example 15, if an attempt is made to produce a convex glass with an angle α of 0.020° or more, the viscosity of the glass ribbon G2 must be increased, so the swing width is increased to 2.0 inches or more.

Although the preferred embodiments of the method for manufacturing convex plate glass according to the present invention have been described above, the present invention is not limited to these embodiments, and various improvements can be made without departing from the scope of the present invention. is of course possible.

In the melting section 10, the frit is melted into the molten glass G1 in the melting kiln 11. Preferably, the stainless steel contained in the frit is removed using a metal detector before the frit is introduced into the melting kiln 11. . Stainless steel contains iron, nickel, chromium, and the like. Conventionally known metal detectors can distinguish between metals and non-metals, but cannot arbitrarily distinguish only stainless steel. The iron necessary for this is also removed from the frit. Metal detectors used to remove stainless steel have a single coil and the magnetic field produced by the coil distinguishes between stainless steel and iron. Iron is magnetized by an alternating magnetic field emitted from the transmitting coil. The iron is detected by magnetic field lines being attracted to the iron and sensed by the receiving coils in a differential configuration. Also, eddy currents are generated in the stainless steel by the alternating magnetic field generated from the transmission coil, and a magnetic field is generated in the vicinity of the stainless steel. Stainless steel is detected by sensing this change in the magnetic field with a differential receiving coil. Since the phase of the eddy current generated in stainless steel lags the phase of the transmission coil by about 90°, it is possible to distinguish between stainless steel and iron by detecting the phase angle. The phase angle of iron is 40-80° and that of stainless steel is 140-180°. The larger the amplitude of the eddy currents generated in the stainless steel, the larger the size of the stainless steel. The metal detector is installed, for example, on a conveyor that transports the blended glass raw materials to the melting furnace 11 . The metal detector preferably has a mechanism for removing only stainless steel of a specific size or larger from the glass raw material. An example of such a mechanism is shown. When a metal or non-metal passes through the metal detector, two analog signals X and Y are input from the metal detector to a PLC (Programmable Logic Controller) to calculate the phase angle and maximum voltage. When the phase angle is 140 to 180°, which indicates stainless steel, and the maximum voltage is equal to or higher than a preset value, the damper installed on the conveyor opens and the stainless steel of a specific size or more is discharged. The included glass raw materials are removed from the conveyor to prevent the stainless steel from entering the melting furnace 11.例文帳に追加

This application is based on a Japanese patent application (Japanese Patent Application No. 2021-141551) filed on August 31, 2021, the contents of which are incorporated herein by reference.

1 glass manufacturing apparatus 10 melting section 11 melting kiln 12 tweel 13 lip 20 forming section 21 molten metal bath 21U upstream end 22 molten metal 23, 23A, 23B top roll 24 heater 24A center heater 24B end heater 25 upstream wall 26 downstream wall 27 side wall 27A shoulder 27B first wall 27C second wall 30 slow cooling section 31 slow cooling chamber 32 transport roll 100 convex glass (plate glass)
200 wedge-shaped glass 300 windshields 301, 302 wedge-shaped glass 303 intermediate film 400 windshield 401 wedge-shaped glass 402 glass 403 intermediate film 500 wedge-shaped glass 507 convex surface 503 line segment 504 intersection (first point)
505 intersection point 506 second point

Claims (15)

1. A method for producing sheet glass, in which a glass ribbon is allowed to float on the surface of the molten metal in a molten metal bath, and a plurality of top rolls are brought into contact with both ends of the glass ribbon in the width direction to form the glass ribbon into a plate shape. There is
   the molten metal bath comprises an upstream wall, a downstream wall and two side walls;
   each of the two sidewalls includes a shoulder that reduces the width of the molten metal bath in the direction of travel of the glass ribbon;
   A ratio W/N between the distance W between the two side walls in the region upstream of the shoulder of the molten metal bath and the distance N between the two side walls in the region downstream of the shoulder of the molten metal bath more than 1.0 and 1.6 or less,
   A method for producing sheet glass, wherein the width direction both ends of the glass ribbon are heated more strongly than the width direction center portion of the glass ribbon in the upstream region of the molten metal bath, thereby producing a sheet glass that is thicker at the width direction center portion than at both end portions. .
2. At a position 20% from the upstream wall with respect to the length from the upstream wall to the downstream wall, the viscosity of the central portion in the width direction of the glass ribbon on the surface of the molten metal is 10 ^ (4.5) (dPa · sec) The method for producing sheet glass according to claim 1, wherein the glass ribbon is heated so as to be equal to or greater than.
3. At a position 20% from the upstream wall with respect to the length from the upstream wall to the downstream wall, the viscosity of the central portion in the width direction of the glass ribbon on the surface of the molten metal is 10^(6.0) (dPa • sec) The method for producing sheet glass according to claim 1 or 2, wherein the glass ribbon is heated so as to:
4. The temperature of the widthwise central portion of the glass ribbon on the surface of the molten metal and the temperature of both widthwise ends of the molten metal at a position 32% from the upstream wall with respect to the length from the upstream wall to the downstream wall. The method for producing sheet glass according to any one of claims 1 to 3, wherein the difference between the temperature and the temperature is 62°C or less.
5. At a position 32% from the upstream wall with respect to the length from the upstream wall to the downstream wall, the viscosity of the central portion in the width direction of the glass ribbon on the surface of the molten metal is 10 ^ (4.7) (dPa · sec) The method for producing sheet glass according to any one of claims 1 to 4, wherein the glass ribbon is heated to a temperature of at least sec).
6. At a position 32% from the upstream wall with respect to the length from the upstream wall to the downstream wall, the viscosity of the central portion in the width direction of the glass ribbon on the surface of the molten metal is 10 ^ (6.3) (dPa · sec) The method for producing sheet glass according to any one of claims 1 to 5, wherein the glass ribbon is heated so as to be below.
7. Claims 1 to 6, wherein the ratio of the maximum width in the width direction of the glass ribbon in the molten metal bath to the length in the width direction of the glass ribbon at the most downstream side of the molten metal bath is 1.4 to 2.2. The method for producing sheet glass according to any one of the above.
8. Width a of the glass ribbon at a position 35% from the upstream wall with respect to the length from the upstream wall to the downstream wall, and length b in the width direction of the glass ribbon at the most downstream side of the molten metal bath. , wherein the ratio a/b is 1.0 to 1.9.
9. At a position 20% from the upstream wall with respect to the length from the upstream wall to the downstream wall, the width direction length A of the glass ribbon and the width direction of the molten metal surface not covered with the glass ribbon The method for producing sheet glass according to any one of claims 1 to 8, wherein the ratio A/B to the length B is 4 to 11.
10. A method for producing wedge-shaped glass, comprising cutting the plate glass obtained by the method for producing plate glass according to any one of claims 1 to 9 to obtain wedge-shaped glass.
11. The wedge-shaped glass has at least one convex surface,
    On a line segment passing through the center of gravity G of the convex surface and connecting two opposite sides of the four sides of the convex surface at the shortest distance, among intersections of the line segment and the sides of the convex surface, the wedge-shaped glass is positioned horizontally. The first point is the point where the thickness of the wedge-shaped glass is smaller in the vertical direction when the glass is placed at If a point on the convex surface located at is the second point, a straight line connecting the first point and the second point forms an angle of 0.020° to 0.050° with the horizontal plane. 11. A method for producing a wedge-shaped glass according to claim 10.
12. The method for manufacturing the wedge-shaped glass according to claim 10 or 11, wherein the ratio T/M between the maximum value T and the minimum value M of the thickness of the wedge-shaped glass is 1.10 to 1.40.
13. Wedge-shaped glass is obtained by cutting the plate glass obtained by the method for manufacturing a plate glass according to any one of claims 1 to 9,
    laminating and crimping the wedge-shaped glass and another plate glass via an intermediate film;
    A method for producing laminated glass.
14. The other sheet glass is the wedge-shaped glass,
    The method for producing a laminated glass according to claim 13.
15. The other sheet glass is a sheet glass having a constant thickness,
    The method for producing a laminated glass according to claim 14.

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