Method for manufacturing a sheet glass, method for manufacturing a wedge glass, and method for manufacturing a laminated glass

Abstract

The molten metal bath has 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 glass ribbon travel. The ratio W / N of the distance between the two side walls in the region upstream of the shoulder and the distance N between the two side walls in the region downstream of the shoulder is greater than 1.0 and less than 1.6. By heating the two ends in the width direction of the molten metal bath to a higher degree than the central portion in the width direction of the glass ribbon in the upstream region, a sheet glass with a central portion in the width direction that is thicker than the two ends is produced.

Description

Technical Field

[0001] This invention relates to methods for manufacturing plate glass, wedge glass, and laminated glass. In particular, it relates to a method for manufacturing plate glass with a convex cross-section (thicker at the center than at both ends) in the width direction orthogonal to the direction of travel of the glass strip. Background Technology

[0002] The thickness of sheet glass manufactured by the float glass process is usually fixed. However, for head-up displays (HUDs) that display information on the windshield of automobiles, for example, a glass of variable thickness is required to prevent ghosting when viewed from the driver's side. Therefore, methods for manufacturing sheet glass with concave, convex, or conical cross-sections in the width direction (hereinafter sometimes simply referred to as the width direction) orthogonal to the direction of travel of the glass strip are being investigated (for example, see Patent Documents 1 and 2). Patent Document 1 discloses cutting a convex-shaped sheet glass with a cross-section that is thicker in the middle of the width direction than at both ends of the width direction to obtain wedge-shaped glass.

[0003] Patent Document 1: International Publication No. 2016 / 117650

[0004] Patent Document 2: US Patent No. 7,122,242 Summary of the Invention

[0005] The technical problem that the invention aims to solve

[0006] Typically, a molten metal bath has an upstream wall, a downstream wall, and two side walls. Sometimes, shoulders that reduce the width of the molten metal bath are provided on each side wall in the direction of the glass ribbon's travel to reduce the amount of molten metal in the bath. Thus, in a molten metal bath with shoulders on the side walls, the portion of the molten metal surface not covered by the glass ribbon sometimes experiences flow in the opposite direction to the glass ribbon's travel. Due to this reverse flow, it is sometimes observed that the glass ribbon on the molten metal surface moves back and forth (oscillates) in the width direction while traveling.

[0007] In particular, when manufacturing convex-sectioned sheet glass as in Patent Document 1, the temperature at the center of the glass strip in the width direction is set lower than that in the case of manufacturing sheet glass with a fixed thickness. As a result, the viscosity of the glass strip increases (the glass strip becomes harder), making it more susceptible to the aforementioned reverse flow, and causing the glass strip to wobble more easily. Moreover, when manufacturing wedge-shaped glass by cutting convex-sectioned sheet glass as in Patent Document 1, the cutting position of the sheet glass is usually fixed. Therefore, if the aforementioned wobble occurs, the wedge angle of the wedge-shaped glass will deviate from that of each product.

[0008] The present invention was made in view of the above circumstances, and its object is to provide a method for manufacturing a sheet glass capable of suppressing the reciprocating movement (swaying) of a glass strip in the width direction. A further object of the present invention is to provide a wedge-shaped glass and a method for manufacturing laminated glass capable of suppressing deviations in the wedge angle of wedge-shaped glass obtained by cutting the sheet glass. Furthermore, in the present invention, convex glass refers to a glass strip in the width direction where the central portion is thicker than both ends in the width direction, or a sheet glass obtained from a glass strip.

[0009] means of solving technical problems

[0010] The above-mentioned objective of the present invention is achieved by the following configuration.

[0011] [1] A method for manufacturing plate glass, comprising: floating a glass strip on the surface of molten metal in a molten metal bath and forming the glass strip into a plate shape by abutting multiple top rollers against the two ends of the glass strip in the width direction; wherein,

[0012] The molten metal bath has an upstream wall, a downstream wall, and two side walls.

[0013] The two sidewalls each include shoulders that reduce the width of the molten metal bath in the direction of travel of the glass ribbon.

[0014] The ratio W / N of the distance W between the two sidewalls in the region upstream of the shoulder of the molten metal bath to the distance N between the two sidewalls in the region downstream of the shoulder of the molten metal bath is greater than 1.0 and less than 1.6.

[0015] By heating the two ends in the width direction to a greater degree than the central portion in the width direction of the glass strip in the upstream region of the molten metal bath, a plate glass with a central portion in the width direction that is thicker than the two ends is manufactured.

[0016] [2] The method for manufacturing plate glass as described in [1], wherein the glass strip is heated at a position 20% away from the upstream wall relative to the length from the upstream wall to the downstream wall, such that the viscosity of the central portion of the glass strip in the width direction on the molten metal surface is 10^(4.5)(dPa·sec) or higher.

[0017] [3] A method for manufacturing plate glass as described in [1] or [2], wherein the glass strip is heated at a position 20% away from the upstream wall relative to the length from the upstream wall to the downstream wall, such that the viscosity of the central portion of the glass strip in the width direction on the molten metal surface is less than 10^(6.0)(dPa·sec).

[0018] [4] A method for manufacturing plate glass as described in any one of [1] to [3], wherein, at a position 32% of the distance from the upstream wall to the downstream wall, the temperature difference between the central portion of the glass strip on the molten metal surface in the width direction and the temperatures at both ends of the molten metal in the width direction is less than 62°C.

[0019] [5] A method for manufacturing plate glass as described in any one of [1] to [4], wherein the glass strip is heated at a position 32% away from the upstream wall relative to the length from the upstream wall to the downstream wall, such that the viscosity of the central portion of the glass strip in the width direction on the molten metal surface is 10^(4.7)(dPa·sec) or higher.

[0020] [6] A method for manufacturing plate glass as described in any one of [1] to [5], wherein the glass strip is heated at a position 32% away from the upstream wall relative to the length from the upstream wall to the downstream wall, such that the viscosity of the central portion of the glass strip in the width direction on the molten metal surface is less than 10^(6.3)(dPa·sec).

[0021] [7] A method for manufacturing plate glass as described in any one of [1] to [6], wherein the ratio of the maximum width of the glass strip in the width direction in the molten metal bath to the length in the width direction of the downstream glass strip in the molten metal bath is 1.4 to 2.2.

[0022] [8] A method for manufacturing plate glass as described in any one of [1] to [7], wherein, at a position 35% away from the upstream wall relative to the length from the upstream wall to the downstream wall, the ratio a / b of the width a of the glass strip to the length b in the width direction of the downstream glass strip of the molten metal bath is 1.0 to 1.9.

[0023] [9] A method for manufacturing plate glass as described in any one of [1] to [8], wherein, at a position 20% away from the upstream wall relative to the length from the upstream wall to the downstream wall, the ratio A / B of the length A in the width direction of the glass strip to the length B in the width direction of the molten metal surface not covered by the glass strip is 4 to 11.

[0024]

[10] A method for manufacturing wedge glass, wherein wedge glass is obtained by cutting a plate glass obtained by any one of the plate glass manufacturing methods described in [1] to [9].

[0025]

[11] The method for manufacturing wedge-shaped glass as described in

[10] , wherein,

[0026] At least one main surface of the wedge-shaped glass is convex.

[0027] On a line segment connecting two opposing sides of the four sides of the convex surface with the shortest distance through the centroid G of the convex surface, the point where the wedge-shaped glass has a smaller thickness in the vertical direction when the wedge-shaped glass is placed in a horizontal location is taken as the first point. The point on the convex surface at a position where the length of the distance from the first point is 2 / 5 of the length of the line segment is taken as the second point. Then the angle between the straight line connecting the first point and the second point and the horizontal plane is 0.020° to 0.050°.

[0028]

[12] The method for manufacturing wedge glass as described in

[10] or

[11] , wherein the ratio of the maximum value T to the minimum value M of the thickness of the wedge glass, T / M, is 1.10 to 1.40.

[0029]

[13] A method for manufacturing laminated glass, wherein,

[0030] The plate glass obtained by the manufacturing method of any one of [1] to [9] is cut to obtain wedge-shaped glass, and

[0031] The wedge-shaped glass is stacked and pressed together with other plate glass through an interlayer film.

[0032]

[14] The method for manufacturing laminated glass as described in

[13] , wherein the other plate glass is the wedge-shaped glass.

[0033]

[15] The method for manufacturing laminated glass as described in

[14] , wherein the other glass plates are glass plates with a fixed thickness.

[0034] Invention Effects

[0035] This invention provides a method for manufacturing a sheet glass capable of suppressing the reciprocating movement of a glass strip in the width direction. It also provides a method for manufacturing wedge-shaped glass and laminated glass capable of suppressing deviations in the wedge angle of wedge-shaped glass obtained by cutting the sheet glass. Attached Figure Description

[0036] Figure 1 In Figure 1 (A) is a diagram of a glass manufacturing apparatus viewed from the width direction. Figure 1 (B) is a diagram of a glass manufacturing apparatus viewed from the thickness direction.

[0037] Figure 2 In Figure 2 (A) is a cross-sectional view in the width direction of glass manufactured by a manufacturing method according to an embodiment of the present invention. Figure 2 (B) is Figure 2 (A) is a wedge-shaped glass obtained by cutting off part A of the glass.

[0038] Figure 3 In Figure 3 (A) is a plan view of the front windshield. Figure 3 (B) is Figure 3 (A) BB section view of the front windshield. Figure 3 (C) is Figure 3 (A) CC section view of the front window glass.

[0039] Figure 4 This is an enlarged view of the top roller.

[0040] Figure 5 In Figure 5 (A) and Figure 5 (B) is a diagram illustrating a glass plate according to an embodiment of the present invention. Figure 5 (A) is a floor plan. Figure 5 (B) is a cross-sectional view in the width direction. Detailed Implementation

[0041] Hereinafter, one embodiment of the present invention will be described. First, the structure of the glass manufacturing apparatus (i.e., float glass manufacturing apparatus) will be described.

[0042] like Figure 1 As shown in (A) and (B), the glass manufacturing apparatus 1 includes a melting section 10, a forming section 20, and an annealing section 30. Furthermore, in the figures, the X direction is the traveling direction of the glass strip G2, X1 is the upstream direction of the glass strip G2, and X2 is the downstream direction of the glass strip G2. The Y direction in the figures is orthogonal to the traveling direction X of the glass strip G2 and represents the width direction of the glass strip G2. The Z direction in the figures is orthogonal to both the traveling direction X and the width direction Y of the glass strip G2 (i.e., the thickness direction of the glass strip G2), with Z1 pointing upwards and Z2 pointing downwards. Figure 1 (A) is a diagram of the glass manufacturing apparatus 1 viewed from the width direction Y. Figure 1 (B) is a diagram of the glass manufacturing apparatus 1 viewed from the thickness direction Z.

[0043] The melting section 10 includes a melting furnace 11, a gate 12, and a lip 13. In the melting section 10, the glass raw material is melted into molten glass G1 by the melting furnace 11. The amount of molten glass G1 supplied to the forming section 20 is adjusted by moving the gate 12 in the vertical direction Z by moving the lip 13, which serves as the flow path of the molten glass G1.

[0044] The forming section 20 includes a molten metal bath (float tank) 21, molten metal 22 stored in the molten metal bath 21, multiple top rollers 23, and a heater 24. In the forming section 20, molten glass G1, continuously supplied by the melting section 10, flows in the traveling direction X and is slowly cooled, forming a glass ribbon G2. That is, the molten glass G1 flows out in the form of a glass ribbon on the molten metal surface (on the surface of the molten metal 22) of the molten metal bath 21, floats on the molten metal surface, and moves in the traveling direction X (downstream direction X2) to form a glass ribbon G2.

[0045] Molten metal 22, such as tin, is stored in the molten metal bath 21. Molten glass G1 is continuously supplied to the surface of the molten metal 22 via a gate 12 and a lip 13.

[0046] The molten metal bath 21 has an upstream wall 25 disposed on the upstream side, a downstream wall 26 disposed on the downstream side, and two side walls 27, 27 connecting these upstream walls 25 and downstream walls 26. Each of the two side walls 27, 27 has a shoulder 27A in the travel direction X of the glass ribbon G2 that reduces the width (dimension in the width direction Y) of the molten metal bath 21. Specifically, the side wall 27 has a first wall 27B connected to the upstream wall 25 and extending linearly in the downstream direction X2, a shoulder 27A connected to the first wall 27B and extending inward in the width direction Y (closer to the direction of the glass ribbon G2) towards the downstream direction X2, and a second wall 27C connected to the shoulder 27A and extending linearly in the downstream direction X2. By providing the shoulder 27A in this way, the amount of molten metal 22 stored in the molten metal bath 21 is reduced.

[0047] The ratio W / N of the distance W between the two sidewalls 27, 27 in the region upstream of the shoulder 27A of the molten metal bath 21 (the distance between the two first walls 27B, 27B) and the distance N between the two sidewalls 27, 27 in the region downstream of the shoulder 27A of the molten metal bath 21 (the distance between the two second walls 27C, 27C) is set to be greater than 1.0 and less than 1.6 (1.0 < W / N ≤ 1.6). When manufacturing convex glass, it is necessary to make the glass strip G2 convex in cross-section in the region upstream of the molten metal bath 21, and to make the width of the glass strip G2 smaller than when manufacturing a glass plate of fixed thickness. Therefore, the area of ​​the portion of the molten metal 22 not covered by the glass strip G2 in the region upstream of the shoulder 27A is easily increased, so the reciprocating movement (swaying) of the glass strip G2 in the width direction Y is more likely to occur compared to manufacturing a glass plate of fixed thickness. When the ratio W / N is below 1.6, the area of ​​the molten metal 22 not covered by the glass ribbon G2 in the region upstream of the shoulder 27A is reduced. Therefore, the upstream flow of molten metal 22 in the X1 direction, which affects the reciprocating motion (swaying) of the glass ribbon G2, is less likely to occur, even when manufacturing wedge-shaped glass. When the ratio W / N is greater than 1.0, the distance between the two sidewalls 27, 27 in the region downstream of the shoulder 27A is narrowed, which reduces the amount of molten metal 22 in the molten metal bath 21.

[0048] The preferred position where the first wall 27B connects to the shoulder 27A is relative to the length L from the upstream wall 25 to the downstream wall 26 (see reference). Figure 1 (B) The position is 60% to 75% away from the upstream wall 25 (0.60L to 0.75L away from the upstream wall 25 in the downstream direction X2). If the position where the first wall 27B connects to the shoulder 27A is 60% to 75% away from the upstream wall 25, then when manufacturing wedge-shaped glass, the area of ​​the molten metal 22 not covered by the glass strip G2 in the region upstream of the shoulder 27A will not be too large, ensuring sufficient forming area for the glass strip even when manufacturing glass of a fixed thickness. The position where the first wall 27B connects to the shoulder 27A is preferably 60% or more away from the upstream wall 25, more preferably 62% or more. The position where the first wall 27B connects to the shoulder 27A is preferably 75% or less away from the upstream wall 25, more preferably 70% or less, further preferably 67% or less, and particularly preferably 65% ​​or less.

[0049] The preferred position for the connection between shoulder 27A and second wall 27C is relative to the length L from upstream wall 25 to downstream wall 26 (see reference). Figure 1(B) The position is 65% to 85% away from the upstream wall 25 (0.65L to 0.85L away from the upstream wall 25 in the downstream direction X2). If the position where the shoulder 27A connects to the second wall 27C is 65% to 85% away from the upstream wall 25, then when manufacturing wedge-shaped glass, the area of ​​the molten metal 22 not covered by the glass strip G2 in the region upstream of the shoulder 27A will not be too large. Furthermore, even when manufacturing glass of a fixed thickness, sufficient forming area can be ensured. The position where the shoulder 27A connects to the second wall 27C is preferably 65% ​​or more away from the upstream wall 25, more preferably 67% or more. The position where the shoulder 27A connects to the second wall 27C is preferably 85% or less away from the upstream wall 25, more preferably 80% or less, further preferably 76% or less, and particularly preferably 70% or less.

[0050] Multiple top rollers 23 are mounted on top of the two ends G2B, G2B in the width direction of the glass strip G2. That is, the multiple top rollers 23 abut against the two ends G2B, G2B in the width direction of the glass strip G2. The circumferential speed of each top roller 23 can be adjusted to adjust the thickness of the glass strip G2.

[0051] Heater 24 is positioned above the molten metal bath 21, Z1. Heater 24 may be, for example, divided into a central heater 24A that heats the central portion G2A of the glass strip G2 in the width direction, and a pair of end heaters 24B, 24B that heat the two ends G2B, G2B in the width direction of the glass strip G2. The central heater 24A and / or the end heaters 24B may also be further separated in the travel direction X and / or the width direction Y, in which case the temperature of the glass strip G2 can be easily adjusted. In the example shown, the two heaters 24 are separated in the travel direction X in a region upstream of the shoulder 27A, a region including the shoulder 27A, and a region downstream of the shoulder 27A. Depending on the relationship between distance W and distance N, the width of the downstream heater 24 is set to be shorter than the width of the upstream heater 24.

[0052] The annealing section 30 includes an annealing chamber 31 and a conveying roller 32. In the annealing section 30, the glass strip G2 formed in the forming section 20 is continuously conveyed by the conveying roller 32 disposed in the annealing chamber 31 while being annealed. Furthermore, the travel speed of the glass strip G2 in the forming section 20 and the annealing section 30 can be adjusted by adjusting the circumferential speed of the conveying roller 32. Here, since top rollers 23 are mounted on both ends G2B of the glass strip G2 in the width direction in the forming section 20, deformation occurs near the locations where the top rollers 23 are mounted on both ends G2B of the glass strip G2 in the width direction. The glass strip G2 is pulled out from the annealing section 30, and the two ends of the glass strip G2 deformed by the top rollers 23 are cut off by a cutting machine. The glass strip G2 is then cut to a specified size using the cutting machine to obtain glass as a product.

[0053] Next, the glass manufactured by the manufacturing method of an embodiment of the present invention (i.e., the float glass manufacturing method) will be described.

[0054] Figure 2 (A) is a cross-sectional view in the width direction of glass manufactured by a manufacturing method according to an embodiment of the present invention. Figure 2 (B) is Figure 2 (A) is a wedge-shaped glass obtained by cutting off part A of the glass. Figure 3 (A) is a plan view of a front window glass manufactured using the manufacturing method of an embodiment of the present invention. Figure 3 (B) is Figure 3 (A) BB section view of the front windshield. Figure 3 (C) is Figure 3 (A) CC section view of the front window glass.

[0055] The plate glass manufactured by the manufacturing method according to an embodiment of the present invention, such as Figure 2 As shown in (A), a convex glass 100 thickens from both ends toward the central portion in the width direction Y. This is achieved by [the glass being positioned at] a predetermined location (e.g., [the glass is then] positioned at a predetermined location]... Figure 2 Cutting the convex glass 100 at part A of (A) yields... Figure 2 (B) shows a wedge-shaped glass 200 with one end thicker than the other in the width direction Y. According to the manufacturing method of the present invention, the reciprocating movement (swaying) of the glass strip G2 in the width direction Y can be suppressed, thus suppressing deviations in the wedge angle β of the wedge-shaped glass 200 obtained by cutting the convex glass 100 (plate glass) formed from the glass strip G2. Here, the convex glass 100 only needs to have a thickness that increases from both ends in the width direction Y towards the center; it can be convex on both sides, or one side can be flat and the other side convex.

[0056] Wedge glass 200 is suitable for, for example Figure 3 The car windshield 300 and 400 with HUD shown in (A) to 3(C) are such that by using wedge-shaped glass 200 for the windshield 300 and 400, the generation of ghosting when viewed from the driver's side can be suppressed without using a special interlayer film (e.g., an interlayer film with a wedge-shaped cross section).

[0057] The application of wedge-shaped glass 200 is not limited to automobile windshields; it can be used for tram windows or as a protective windshield for motorcyclists. Any type of glass can be used as long as it can display information. Furthermore, the application of wedge-shaped glass 200 is not limited to information display glass in vehicles; it can also be used for various other information display glass applications. Moreover, it can be used in various devices utilizing continuously changing transmission characteristics for purposes other than information display.

[0058] in addition, Figure 3 (B) The front window glass 300 shown is a laminated glass made by laminating and pressing an intermediate film 303 between wedge-shaped glass 301 and wedge-shaped glass 302.

[0059] As another form of windshield glass, one of the two panes of glass can also be a glass of fixed thickness. (For example, a 400mm windshield...) Figure 3 As shown in (C), laminated glass is made by sandwiching an intermediate film 403 between a wedge-shaped glass 401 and a glass 402 of fixed thickness and pressing them together.

[0060] Next, a method for manufacturing a plate glass according to an embodiment of the present invention will be described.

[0061] According to the glass manufacturing method of an embodiment of the present invention, when manufacturing a convex glass 100 with a convex cross-section in the width direction Y, which is orthogonal to the travel direction X of the glass strip, the glass strip G2 formed by continuously feeding molten glass G1 melted in the melting section 10 onto the molten metal 22 is heated more intensely at both ends G2B, G2B in the width direction than at the center G2A in the width direction in the upstream region of the molten metal bath 21. By heating the two ends G2B, G2B in the width direction more intensely than at the center G2A in the width direction of the glass strip G2, the viscosity of the two ends G2B, G2B in the width direction of the glass strip G2 is less likely to rise than that of the center G2A in the width direction. This makes it easier to thin the thickness of the two ends G2B, G2B in the width direction of the glass strip G2 and to thicken the thickness of the center G2A in the width direction.

[0062] Furthermore, when manufacturing convex glass in the aforementioned conventional float glass manufacturing apparatus 1, it is preferable to substantially not use the central heater 24A located in the middle of the width direction in the upstream region of the molten metal bath 21, but instead use only the end heaters 24B located at both ends in the width direction for heating. Here, "upstream region" refers to the area of ​​the molten metal bath 21 that is approximately 70% upstream of the furnace 11. "Substantially not using the central heater 24A" means that the output of the central heater 24A is less than 1 kW / m². 2 By essentially omitting the central heater 24A and utilizing only the end heaters 24B for heating, the viscosity of the glass ribbon at both ends G2B in the width direction is less likely to rise than that at the central part G2A in the width direction. This makes it easier for the thickness of the glass ribbon at both ends G2B in the width direction to decrease, while the thickness of the central part G2A in the width direction to increase. The output of the central heater 24A can also be 0 kW / m. 2 Alternatively, the central portion G2A in the width direction can also be cooled.

[0063] In the downstream region, which is a 30% area near the annealing chamber 31 of the molten metal bath 21, the central portion G2A in the width direction of the glass strip can be heated by the central heater 24A.

[0064] Furthermore, it is preferable to heat the glass strip G2 on the molten metal surface such that the cooling rate of the two ends G2B, G2B in the width direction is 6.1°C / m or less. Here, "cooling rate" refers to the temperature decrease of the glass strip G2 as it moves 1m in the traveling direction X within the molten metal bath 21. When the cooling rate of the two ends G2B, G2B in the width direction of the glass strip G2 is 6.1°C / m or less, the viscosity of the two ends G2B, G2B in the width direction is less likely to increase, making it easier for the two ends G2B, G2B in the width direction to become thinner and the central part G2A in the width direction to become thicker. The cooling rate of the two ends G2B, G2B in the width direction is more preferably 6.0°C / m or less, and even more preferably 5.9°C / m or less. In addition, in this specification, when the cooling rate of the ends of the glass strip G2 in the width direction is indicated, the ends refer to a position 50mm from the end of the glass strip G2 towards the center in the width direction.

[0065] On the other hand, it is preferable to heat the glass ribbon G2 so that the cooling rate at both ends G2B, G2B in the width direction is 3.0℃ / m or higher. When the cooling rate at both ends G2B, G2B in the width direction is 3.0℃ / m or higher, the glass ribbon G2 can be easily and sufficiently cooled. The cooling rate at both ends G2B, G2B in the width direction can be 4.0℃ / m or higher, or it can be 5.0℃ / m or higher.

[0066] Preferably, the cooling rate of the two ends G2B in the width direction of the glass ribbon G2 is slower than that of the central part G2A in the width direction. Because the cooling rate of the two ends G2B is slower than that of the central part G2A, the viscosity at both ends is less likely to increase, making it easier for the two ends G2B to become thinner and the central part G2A to become thicker.

[0067] Preferably, the cooling rate of the two ends G2B of the glass ribbon G2 in the width direction is slower than that of the central part G2A in the width direction by at least 0.3℃ / m. This slower cooling rate (at least 0.3℃ / m) makes it difficult for the viscosity of the two ends G2B to increase, leading to thinning of the two ends G2B and thickening of the central part G2A. The cooling rate of the two ends G2B can be slower than that of the central part G2A by at least 0.4℃ / m or at least 0.5℃ / m.

[0068] Furthermore, it is preferable to control the heating temperature of G2B, G2B at both ends in the width direction so that the viscosity of G2B, G2B at both ends in the width direction of the glass strip G2 on the molten metal surface is 10. 4.9 The position (dPa·sec) and viscosity are 10 6.1 The distance between the positions (dPa·sec) is 15m or more. When the distance is 15m or more, the viscosity of G2B at both ends in the width direction is less likely to increase, making it easier for G2B at both ends in the width direction to become thinner and for G2A in the central part in the width direction to become thicker. More preferably, the distance is 16m or more, and even more preferably 16.5m or more. Here, the viscosity of the glass strip G2 is calculated by measuring the temperature of the glass strip G2 using a radiation thermometer and then using the viscosity curve of the glass (Fulcher formula) based on the measured temperature. Furthermore, in this specification, when characterizing the viscosity of the ends of the glass strip G2 in the width direction, the ends, as described above, refer to a position 50mm from the end of the glass strip G2 towards the center in the width direction.

[0069] On the other hand, it is preferable to control the heating temperature of the two ends G2B, G2B in the width direction so that the viscosity of the two ends G2B, G2B in the width direction of the glass strip G2 on the molten metal surface is 10. 4.9 The position (dPa·sec) and viscosity are 10 6.1 The distance between the (dPa·sec) positions is less than 30m. At distances less than 30m, the glass ribbon is easily and sufficiently cooled. The aforementioned distance can be less than 25m or less than 20m.

[0070] Furthermore, top rollers 23 are placed on top of the two ends G2B, G2B of the glass strip G2 heated by heater 24 in the width direction. The glass strip is shaped into the desired width, thickness, and shape by the action of these top rollers 23. At this time, it is preferable to adjust the circumferential speed of each top roller 23 to be faster towards the downstream side. In addition, when manufacturing the convex glass 100, it is preferable to rotate multiple top rollers 23 in such a way that the circumferential speed of the top roller 23A upstream in the travel direction X of the glass strip G2 is slower than the circumferential speed of the top roller 23B downstream. Furthermore, by using only the end heaters 24B without actually using the central heater 24A, the viscosity of the two ends G2B, G2B in the width direction of the glass strip is less likely to rise than that of the central part G2A in the width direction. As a result, when the width of the glass strip G2, which is spread out on both sides of the rotation axis of the upstream top roller 23A, is widened, the two ends G2B, G2B in the width direction of the glass strip G2 can be thinned, and the central part G2A in the width direction can be thickened.

[0071] The upstream top roller 23A refers to the top rollers at both ends G2B of the glass belt G2 traveling in the molten metal bath 21 in the width direction. Among the multiple pairs of top rollers 23 arranged on G2B, the top rollers 23 closest to the melting furnace 11 can be only one pair, or two or three pairs. Preferably, there are two pairs. Specifically, the pair of top rollers 23 closest to the melting furnace 11 is referred to as the upstream top roller 23A. The downstream top roller 23B refers to the top rollers 23 closest to the annealing chamber 31. It can be only one pair, or two or three pairs. Specifically, the pair of top rollers 23 closest to the annealing chamber 31 is referred to as the downstream top roller 23B. Furthermore, Figure 1 (A) and Figure 1 (B) illustrates an example where there are two pairs of upstream top rollers 23A and two pairs of downstream top rollers 23B.

[0072] Preferably, 7 to 15 pairs of top rollers 23 are arranged at both ends G2B in the width direction of the glass strip G2. Arranging 7 to 15 pairs makes it easy to adjust the glass strip G2 to a specified thickness. More preferably, 8 to 13 pairs of top rollers 23 are arranged. Furthermore, in... Figure 1 In (A) and (B), an example is shown where the top roller 23 is arranged in pairs at both ends G2B in the width direction of the glass belt G2.

[0073] Additionally, at both ends G2B of the glass strip G2 on the molten metal surface, the viscosity of G2B is 10. 5.3 In the region below (dPa·sec) (hereinafter referred to as the low viscosity region), the top rollers 23 configured at both ends G2B in the width direction can be 8 pairs or less, 7 pairs or less, 6 pairs or less, 5 pairs or less, or 3 pairs or less.

[0074] On the other hand, the viscosity of the glass strip G2 at both ends G2B in the width direction on the molten metal surface is greater than 10. 5.3 In the region of (dPa·sec) (hereinafter referred to as the high viscosity region), the top rollers 23 configured at both ends of G2B in the width direction can be 10 pairs or less, 8 pairs or less, 6 pairs or less, 4 pairs or less, 2 pairs or less, or 1 pair or less.

[0075] The upstream top roller 23A can also be configured in the low viscosity region, and the downstream top roller 23B can also be configured in the high viscosity region.

[0076] The glass strip G2 on the molten metal surface has two ends G2B in the width direction. The viscosity of G2B is 10. 5.3In the top rollers 23 configured in the region below (dPa·sec) (low viscosity region), the difference in circumferential speed between at least one pair of adjacent top rollers 23, 23 in the travel direction X is preferably 35 (m / h) or more. When the speed is 35 (m / h) or more, the viscosity of the glass belt G2 is 10... 5.3 In the region below (dPa·sec), the glass strip G2 is stretched downstream in the X2 direction, which thins the two ends G2B, G2B in the width direction. As a result, the two ends G2B, G2B in the width direction are thinned, and the central part G2A in the width direction is thickened, thereby producing a plate glass with a convex cross-section in the width direction Y.

[0077] In the molten metal bath 21, glass ribbon G2 has two ends G2B in the width direction, and the viscosity of G2B is 10. 5.3 In the region below (dPa·sec), the difference in circumferential speed between at least one set of adjacent top rollers 23, 23 in the direction of travel X can be above 40 (m / hour), above 45 (m / hour), or above 50 (m / hour).

[0078] On the other hand, at both ends G2B of the glass strip G2 on the molten metal surface, the viscosity of G2B is 10. 5.3 In the region of (dPa·sec) or lower (low viscosity region), the difference in circumferential speed between at least one pair of adjacent top rollers 23, 23 in the travel direction X is preferably less than 100 (m / h). At less than 100 (m / h), the thickness of the glass strip G2 can be easily adjusted. It can be less than 80 (m / h) or less than 60 (m / h).

[0079] The circumferential speed R of the uppermost top roller 23A is preferably 120 m / h or less. At 120 m / h or less, the width of the glass strip G2 extending to both sides of the rotation axis of the pair of uppermost top rollers 23A can be increased. As a result, it is easier to make the ends G2B, G2B of the glass strip G2 in the width direction thinner and the central part G2A in the width direction thicker. The circumferential speed R of the uppermost top roller 23A can be 110 m / h or less, 100 m / h or less, 90 m / h or less, 80 m / h or less, 70 m / h or less, or 60 m / h or less.

[0080] On the other hand, the circumferential speed R of the uppermost top roller 23A is preferably 30 (m / hour) or higher. At 30 (m / hour) or higher, it is easier to adjust the thickness of the glass strip G2. The circumferential speed R of the uppermost top roller 23A can be 40 (m / hour) or higher, or 50 (m / hour) or higher.

[0081] Figure 4 This is an enlarged view of the top roller 23. (See image below.) Figure 4 As shown, to adjust the thickness of the glass belt G2, the angle D formed by the traveling direction X of the glass belt G2 and the rotation axis J of the top roller 23 can be adjusted. By adjusting the angle D of the upstream top roller 23A to 75°–90° and the angle D of the downstream top roller 23B to 90°–105°, it is easy to make the thickness of the two ends G2B of the glass belt G2 in the width direction thinner. The angle D of the upstream top roller 23A is more preferably 80°–85°, and even more preferably 81°–84°. The angle D of the downstream top roller 23B is more preferably 95°–100°, and even more preferably 96°–99°.

[0082] In addition, by adjusting the traveling speed of the glass strip G2 in the forming section 20 and the annealing section 30, the glass strip G2 upstream of the molten metal bath 21 can be easily spread in the width direction Y, so that the thickness of the two ends G2B, G2B in the width direction of the glass strip G2 becomes thinner.

[0083] The traveling speed of the glass ribbon G2 in the forming section 20 or the annealing section 30 can be 200 to 1500 m / h. By setting the traveling speed of the glass ribbon G2 in the forming section 20 and the annealing section 30 to 200 to 1500 m / h, it is easier for the glass ribbon G2 upstream of the molten metal bath 21 to expand in the width direction Y, and it is easier to thin the thickness of the two ends G2B of the glass ribbon G2 in the width direction. The traveling speed of the glass ribbon G2 can 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 the glass ribbon G2 can be 1300 m / h or less, 1100 m / h or less, or 900 m / h or less.

[0084] The difference (T-M) between the maximum value T and the minimum value M of the thickness of the glass pane manufactured by the manufacturing method of an embodiment of the present invention is preferably 0.1 mm or more. When the difference (T-M) is 0.1 mm or more, ghosting can be reduced even when used as information display glass in vehicles with a large angle between the windshield and the horizontal plane. Here, the difference (T-M) between the maximum value T and the minimum value M of the glass pane refers to the difference between the maximum and minimum thickness of the convex glass 100 obtained by cutting off both ends of the glass strip G2 deformed by the top roller 23 in the width direction Y using a cutting machine. The difference (T-M) can 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 (T-M) can be 1.5 mm or less. When it is 1.5 mm or less, the distortion of the reflected image can be suppressed even when used as information display glass in vehicles with a small angle between the windshield and the horizontal plane. The difference (T-M) can be less than 1.3mm, less than 1.2mm, less than 1.1mm, or less than 1.0mm. For example, when this glass plate is used as the windshield of a car, the difference between the maximum value T and the minimum value M (T-M) of the optimal glass plate thickness can be selected based on the angle at which the windshield is installed, as well as the installation angle and position of the illuminator used to display information.

[0085] The glass pane manufactured by the manufacturing method according to an embodiment of the present invention preferably has a maximum height Rz of the roughness curve of its main surface when the reference length is 25 mm as specified in JIS B0601:2001, which is less than 0.3 μm. When the Rz of the main surface of the glass pane is less than 0.3 μm, for example, when the glass pane is used as information display glass, the view seen through the glass will not be distorted. Furthermore, the reflected image when displaying information on the glass pane is less prone to distortion. Here, the roughness curve is represented by its shape and waveform. More preferably, Rz is less than 0.25 μm, further preferably less than 0.2 μm, particularly preferably less than 0.18 μm, and most preferably less than 0.16 μm. The Rz of the main surface of the glass pane can be reduced by slowing down the travel speed V of the glass belt G2 in the annealing section 30. Here, the main surface of the glass plate refers to the surface of the glass strip G2 that contacts the molten metal 22 in the molten metal bath 21 (hereinafter referred to as the molten metal contact surface), and the surface opposite the molten metal contact surface that does not contact the molten metal 22 (hereinafter referred to as the molten metal non-contact surface).

[0086] like Figure 1As shown in (B), the ratio W / N of the distance W between the two sidewalls 27, 27 in the region upstream of the shoulder 27A of the molten metal bath 21 (the distance between the two first walls 27B, 27B) and the distance N between the two sidewalls 27, 27 in the region downstream of the shoulder 27A of the molten metal bath 21 (the distance between the two second walls 27C, 27C) is preferably greater than 1.0 and less than 1.6 (1.0 < W / N ≤ 1.6). When W / N is less than 1.6, the area of ​​the portion of the molten metal 22 not covered by the glass strip G2 in the region upstream of the shoulder 27A is reduced, and the flow of the molten metal 22 in the upstream direction X1 is less likely to occur, and the reciprocating movement (swaying) of the glass strip G2 in the width direction Y is less likely to occur. Therefore, it is possible to suppress the convex glass 100 (refer to) obtained by the plate glass manufacturing method of this embodiment. Figure 2 A) The wedge-shaped glass obtained by cutting 200 (refer to) Figure 2 The deviation of the wedge angle β in B).

[0087] If the ratio W / N is greater than 1.0, the distance between the two sidewalls 27,27 in the downstream region of the shoulder 27A can be narrowed, thereby reducing the amount of molten metal 22 in the molten metal bath 21.

[0088] The W / N ratio is more preferably 1.1 or higher, and even more preferably 1.3 or higher. Furthermore, the W / N ratio is more preferably 1.55 or lower, and even more preferably 1.50 or lower.

[0089] Preferably, in the length L relative to the upstream wall 25 to the downstream wall 26 (refer to) Figure 1 (B) The glass strip G2 is heated by heater 24 at a position 20% away from the upstream wall 25 (0.2L away from the upstream wall 25 in the downstream direction X2), so that the viscosity of the central portion G2A of the glass strip G2 in the width direction on the molten metal surface is 10^(4.5) (dPa·sec) or higher. When the viscosity of the central portion G2A in the width direction is 10^(4.5) (dPa·sec) or higher, it is easy to make the two ends G2B, G2B in the width direction thinner and the central portion G2A in the width direction thicker. Therefore, the convex glass 100 (refer to) obtained by the glass manufacturing method of this embodiment can be made... Figure 2 A) The wedge-shaped glass obtained by cutting 200 (refer to) Figure 2 The wedge angle β of B) increases.

[0090] At a position 20% away from the upstream wall 25 (0.2L away from the upstream wall 25 along the downstream direction X2), the viscosity of the central portion G2A of the glass strip G2 on the molten metal surface in the width direction is more preferably 10^(5.0) (dPa·sec) or higher, and even more preferably 10^(5.3) (dPa·sec) or higher. This is because the temperature of the central portion G2A of the glass strip G2 in the width direction can be relatively lower than the temperature of the two ends G2B in the width direction, thereby increasing the wedge angle β.

[0091] Preferably, in the length L relative to the upstream wall 25 to the downstream wall 26 (refer to) Figure 1 (B) The glass strip G2 is heated by heater 24 at a position 20% away from the upstream wall 25 (0.2L away from the upstream wall 25 in the downstream direction X2), so that the viscosity of the central portion G2A of the glass strip G2 in the width direction on the molten metal surface is below 10^(6.0) (dPa·sec). If the viscosity of the glass strip G2 is too high, the top roller 23 will have difficulty entering the glass strip G2, making it difficult to control the position of the glass strip G2, and thus reciprocating motion (swaying) in the width direction is likely to occur. In this embodiment, the viscosity of the central portion G2A in the width direction is below 10^(6.0) (dPa·sec), thus suppressing the occurrence of swaying.

[0092] At a position 20% away from the upstream wall 25 (0.2L away from the upstream wall 25 along the downstream direction X2), the viscosity of the central portion G2A of the glass strip G2 on the molten metal surface in the width direction is more preferably below 10^(5.8) (dPa·sec), and even more preferably below 10^(5.6) (dPa·sec). This is because the lower the viscosity of the glass strip G2, the easier it is for the top roller 23 to enter the glass strip G2, and the more effectively it can suppress the occurrence of swaying.

[0093] In the length L relative to the upstream wall 25 to the downstream wall 26 (refer to) Figure 1(B) At a position 32% away from the upstream wall 25 (0.32L away from the upstream wall 25 along the downstream direction X2), the temperature difference (I-K) between the central portion G2A of the glass strip G2 in the width direction and the two ends of the molten metal 22 in the width direction is preferably 62°C or less. When the temperature difference (I-K) is less than 62°C, the viscosity difference between the two ends and the central portion of the glass strip G2 in the width direction is smaller, making it easier for the two ends G2B, G2B in the width direction to become thinner and the central portion G2A in the width direction to become thicker. The temperature difference (I-K) is more preferably less than 50°C, and even more preferably less than 40°C. To suppress excessive output to the heater 24, the lower limit of the temperature difference (I-K) can be above 0°C, above 10°C, or above 15°C. Furthermore, the temperature K at the two ends of the molten metal 22 in the width direction refers to the temperature at a position 50 mm from each of the two side walls 27, 27 of the molten metal bath 21 towards the center in the width direction.

[0094] Preferably, in the length L relative to the upstream wall 25 to the downstream wall 26 (refer to) Figure 1 (B) The glass strip G2 is heated by heater 24 at a position 32% away from the upstream wall 25 (0.32L away from the upstream wall 25 in the downstream direction X2), so that the viscosity of the central portion G2A of the glass strip G2 in the width direction on the molten metal surface is 10^(4.7) (dPa·sec) or higher. When the viscosity of the central portion G2A in the width direction is 10^(4.7) (dPa·sec) or higher, it is easy to make the two ends G2B, G2B in the width direction thinner and the central portion G2A in the width direction thicker. Therefore, the convex glass 100 (refer to) obtained by the plate glass manufacturing method of this embodiment can be made... Figure 2 A) The wedge-shaped glass obtained by cutting 200 (refer to) Figure 2 The wedge angle β of B) increases.

[0095] At a position 32% away from the upstream wall 25 (0.32L away from the upstream wall 25 along the downstream direction X2), the viscosity of the central portion G2A of the glass strip G2 on the molten metal surface in the width direction is more preferably 10^(5.0) (dPa·sec) or higher, and even more preferably 10^(5.3) (dPa·sec) or higher. This is because the temperature of the central portion G2A of the glass strip G2 in the width direction can be lower than the temperature of the two ends G2B, G2B in the width direction, thereby increasing the wedge angle β.

[0096] Preferably, in the length L relative to the upstream wall 25 to the downstream wall 26 (refer to) Figure 1(B) The glass strip G2 is heated by heater 24 at a position 32% away from the upstream wall 25 (0.32L away from the upstream wall 25 in the downstream direction X2), so that the viscosity of the central portion G2A of the glass strip G2 in the width direction on the molten metal surface is below 10^(6.3) (dPa·sec). If the viscosity of the glass strip G2 is too high, the top roller 23 will have difficulty entering the glass strip G2, making it difficult to control the position of the glass strip G2, and thus reciprocating motion (swaying) in the width direction is likely to occur. In this embodiment, the viscosity of the central portion G2A in the width direction is below 10^(6.3) (dPa·sec), thus suppressing the occurrence of swaying.

[0097] At a position 32% away from the upstream wall 25 (0.32L away from the upstream wall 25 in the downstream direction X2), the viscosity of the central portion G2A of the glass strip G2 on the molten metal surface in the width direction is more preferably below 10^(6.0) (dPa·sec), and even more preferably below 10^(5.8) (dPa·sec). This is because the lower the viscosity of the glass strip G2, the easier it is for the top roller 23 to enter the glass strip G2, and the better it can suppress the occurrence of swaying.

[0098] Preferably, the ratio c / b of the maximum width c of the glass strip G2 in the width direction Y of the molten metal bath 21 (located between the upstream wall 25 and the downstream wall 26) to the length b of the downstream glass strip G2 in the width direction Y of the molten metal bath 21 is 1.4 to 2.2 (1.4 ≤ c / b ≤ 2.2). When the ratio c / b is 1.4 to 2.2, the area of ​​the molten metal 22 not covered by the glass strip G2 is reduced, thus making it less likely for the molten metal 22 to flow upstream in the X1 direction, and making it less likely for the glass strip G2 to reciprocate (sway) in the width direction Y.

[0099] Furthermore, the ratio c / b is more preferably 1.6 or higher, and even more preferably 1.7 or higher. The ratio c / b is more preferably 2.1 or lower, and even more preferably 2.0 or lower. The length of the glass belt G2 in the width direction in the molten metal bath 21 is determined based on an image of the glass belt G2 obtained by a camera and the position of the top roller.

[0100] At a position 35% of the distance from the upstream wall 25 to the downstream wall 26 (0.35L from the upstream wall 25 along the downstream direction X2), the ratio a / b of the width a (not shown) of the glass strip G2 to the length b (not shown) of the downstream glass strip G2 in the width direction Y of the molten metal bath 21 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 molten metal 22 not covered by the glass strip G2 is reduced, thus making it less likely for the molten metal 22 to flow in the upstream direction X1, and making it less likely for the glass strip G2 to reciprocate (sway) in the width direction Y.

[0101] Furthermore, a ratio a / b is more preferably 1.3 or higher, and even more preferably 1.4 or higher. A ratio a / b is more preferably 1.8 or lower, even more preferably 1.7 or lower, and particularly preferably 1.6 or lower.

[0102] At a position 20% away from the upstream wall 25 (0.2L away from the upstream wall 25 in the downstream direction X2) relative to the length L from the upstream wall 25 to the downstream wall 26, the ratio A / B of the length A (not shown) of the glass strip G2 in the width direction Y to the length B (not shown) of the molten metal surface not covered by the glass strip G2 is preferably 4 to 11 (4 ≤ A / B ≤ 11). Length B is the length of the molten metal in the width direction Y on both sides of the glass strip G2 at a position 20% away from the upstream wall 25 (0.2L away from the upstream wall 25 in the downstream direction X2). Therefore, 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 (refer to...). Figure 1 (B) is obtained by subtracting length A (B = W - A). Thus, since the ratio A / B is set to 4-11, the molten metal 22 is largely covered by the glass strip G2, making it less likely for the molten metal 22 to flow upstream in the X1 direction, and suppressing the reciprocating motion (swaying) in the width Y direction of the glass strip G2. Length B is determined based on an image of the molten metal surface not covered by the glass strip G2 taken by a camera.

[0103] Furthermore, if the ratio A / B is less than 4, the exposed area of ​​the molten metal 22 will become wider, and swaying of the glass ribbon G2 is likely to occur. If the ratio A / B is greater than 11, the width of the glass ribbon G2 becomes wider relative to the molten metal bath 21, making it difficult to control the width of the glass ribbon G2 using the top roller 23, or it may easily interfere with components disposed in the molten metal bath 21. The ratio A / B is preferably controlled to be 11 or less. Furthermore, 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.

[0104] Wedge-shaped glass and laminated glass are manufactured using plate glass produced by the aforementioned plate glass manufacturing method.

[0105] Reference Figure 2 (A)~2(B) and Figure 3 Sections (A) to (C) describe a method for manufacturing wedge-shaped glass and laminated glass according to an embodiment of the present invention. Here, a method for manufacturing laminated glass for a vehicle windshield will be described as an example.

[0106] A method for manufacturing wedge-shaped glass according to one embodiment of the present invention includes a step of cutting a convex-shaped plate glass 100 obtained by the above-described plate glass manufacturing method to obtain wedge-shaped glass 200. A method for manufacturing laminated glass according to one embodiment of the present invention includes a step of cutting a convex-shaped plate glass 100 obtained by the above-described plate glass manufacturing method to obtain wedge-shaped glass 200, and a step of laminating and pressing the wedge-shaped glass 200 with other plate glass layers through an interlayer film.

[0107] First, using the aforementioned method for manufacturing sheet glass, a convex glass 100 with a thickness that increases towards the center in the width direction is obtained (see reference). Figure 2 A). By cutting the convex glass 100 at a specified location (part A in the figure), a wedge-shaped glass 200 with one end thicker than the other in the width direction can be obtained (see reference). Figure 2 B). The cutting method is not limited. For example, a cutting tool can be used to make a scribe line along the shape of the window glass on the convex glass 100, breaking it to cut out the convex glass 100, thereby obtaining the wedge-shaped glass 200. The wedge-shaped glass 200 can be chamfered at its periphery.

[0108] Next, the wedge-shaped glass 200 and the other glass panes, with a release agent between them, are bent by gravity bending or other methods. The pair of glass panes are then bent and annealed in a furnace while being heated and softened. Furthermore, the bending method is not limited to gravity bending; the pair of glass panes can also be shaped by pressure bending, or each pane can be bent separately without overlapping.

[0109] Next, laminated glass is obtained by stacking and pressing wedge-shaped glass 200 with other sheet glass through an interlayer film. The other sheet glass can be wedge-shaped glass 200 or sheet glass of fixed thickness. Sheet glass of fixed thickness can be obtained by known methods and then cut using the aforementioned cutting method. In the case of installation on a vehicle where the windshield has a large angle relative to the horizontal plane, the other sheet glass is a laminated glass 300 with wedge-shaped glass 200 (see reference). Figure 3 (A) and Figure 3 (B) The reflected image is less prone to distortion when displaying information. Other laminated glass is laminated glass with a fixed thickness (see [reference]). Figure 3C) ensures that the view seen through the windshield remains undistorted. Polyvinyl butyral can be used as a material for the interlayer membrane.

[0110] During the pressing process, firstly, a degassing treatment is performed by removing air from between the pair of glass plates and the interlayer film. The pair of glass plates and the interlayer film are then heated and bonded. For example, the air can be removed by placing the overlapping pair of glass plates and the interlayer film in a rubber bag and heating under reduced pressure. Alternatively, the clamping roller method or the rubber channel method can be used. Next, the overlapping pair of glass plates and the interlayer film is pressurized using an autoclave, and then heated and bonded. For example, polyvinyl butyral (PVB) or ethylene vinyl acetate (EVA) can be used as the interlayer film.

[0111] The wedge-shaped glass according to one embodiment of the present invention will be described below.

[0112] Figure 5 (A) and 5(B) show a wedge-shaped glass 500 according to an embodiment of the present invention. Figure 5 (A) is a floor plan. Figure 5 (B) is a sectional view.

[0113] The wedge-shaped glass 500 of one embodiment of the present invention is obtained, for example, by cutting a plate glass obtained by the above-described plate glass manufacturing method. The cutting method is not limited; for example, a scribe line can be formed along the shape of the window glass on the plate glass using a cutting tool to break it, thereby obtaining the wedge-shaped glass 500 of one embodiment of the present invention.

[0114] When the wedge-shaped glass 500 of one embodiment of the present invention is used as the windshield of a vehicle, the wedge-shaped glass 500 is installed on the vehicle, for example, with the edge 502 of the smallest thickness located at the bottom, and information is displayed below the edge of the windshield with the smallest thickness.

[0115] The wedge-shaped glass 500 of one embodiment of the present invention is characterized by at least one main surface being a convex surface 507. By making the main surface convex 507, the reflected image when displaying information on the glass is less prone to distortion. Furthermore, compared to the case where the main surface is concave, the thickness of the upper part of the windshield where no information is displayed is reduced, thereby reducing the weight of the windshield and improving vehicle fuel efficiency. The position of the information displayed on the windshield is not limited to the bottom; it can be the top, left, right, or center. The glass is installed in a manner that reduces the thickness of the area where the information is displayed. Regardless of the position of the displayed information, as long as the main surface is convex 507, the thickness of the portion where no information is displayed can be reduced compared to the case where the main surface is concave, thereby reducing the weight of the windshield.

[0116] In one embodiment of the present invention, the wedge-shaped glass 500 is preferably rectangular. A rectangular wedge-shaped glass 500 facilitates operations such as transport. Here, the rectangle is not limited to a precise rectangle; the edges may also be curved. Furthermore, the angle is not limited to 90°; 80–100° is acceptable.

[0117] The wedge-shaped glass 500 of one embodiment of the present invention may have a notch, and the corners may be rounded.

[0118] In the wedge-shaped glass 500 of one embodiment of the present invention, on the line segment 503 obtained by connecting two opposing sides of the four sides 501, 502, 508, and 509 of the convex surface 507 with the shortest distance through the centroid G of the convex surface 507, the point of intersection 504 and 505 of the line segment 503 with the side of the convex surface 507 with the smaller thickness of the wedge-shaped glass 500 in the vertical direction when the wedge-shaped glass 500 is placed in a horizontal position is designated as the first point 504, and the point on the convex surface 507 at a position 2 / 5 of the length of the line segment 503 from the first point 504 is designated as the second point 506. The angle α between the straight line H obtained by connecting the first point 504 and the second point 506 and the horizontal plane is preferably 0.020° to 0.050°. The thickness of the glass plate can be determined using instruments such as laser displacement gauges, precision thickness gauges (Microgage), and ultrasonic thickness gauges, while α is calculated based on the measured thickness.

[0119] When the windshield is mounted on a vehicle with a small angle between the windshield and the horizontal plane, a smaller angle α of the wedge-shaped glass 500 is preferred because it reduces the ghosting of the projected image on the windshield. Conversely, when the windshield is mounted on a vehicle with a large angle α between the windshield and the horizontal plane, a larger angle α of the wedge-shaped glass 500 is preferred because it reduces the ghosting of the projected image on the windshield.

[0120] The wedge-shaped glass 500 of one embodiment of the present invention reduces ghosting when displaying information on a panel glass in vehicles with a large angle of the windshield relative to the horizontal plane by setting the angle α to 0.020° or higher. The angle α can be 0.023° or higher, 0.025° or higher, 0.030° or higher, or 0.033° or higher. Furthermore, by setting the angle α to 0.050° or lower, ghosting is reduced even when displaying information on a panel glass in vehicles with a small angle of the windshield relative to the horizontal plane. The angle α can also be 0.04° or lower. The optimal angle α can be selected based on the angle of the windshield installation and the installation angle and position of the illuminator used for displaying information.

[0121] In one embodiment of the present invention, the wedge-shaped glass 500 preferably has a maximum height Rz of the roughness curve of its main surface when the reference length is 25 mm as specified in JIS B0601:2001 is less than 0.3 μm. Because Rz is less than 0.3 μm, the view seen through the wedge-shaped glass 500 is not distorted. Furthermore, the reflected image when displaying information on the glass plate is less prone to distortion.

[0122] In one embodiment of the present invention, the wedge-shaped glass 500 preferably has a thickness difference (T-M) of at least 0.1 mm between the maximum value T and the minimum value M. Since the thickness difference (T-M) is at least 0.1 mm, ghosting can be suppressed when the glass is installed in a vehicle with a large angle between the windshield and the horizontal plane for use as an information display. Alternatively, the difference (T-M) can be less than 1.5 mm. When the difference is less than 1.5 mm, ghosting can be suppressed when the glass is installed in a vehicle with a small angle between the windshield and the horizontal plane for use as an information display. The difference (T-M) can be less than 1.3 mm, less than 1.2 mm, less than 1.1 mm, or less than 1.0 mm.

[0123] In one embodiment of the present invention, the ratio T / M of the maximum thickness T to the minimum thickness M of the wedge-shaped glass 500 is preferably 1.10 to 1.40. When T / M is 1.10 or higher, ghosting can be suppressed when displaying information on the glass panel in vehicles with a large angle between the windshield and the horizontal plane. The ratio T / M can be 1.12 or higher, 1.15 or higher, 1.20 or higher, or 1.25 or higher. Furthermore, when the ratio T / M is 1.40 or lower, reflected images can be suppressed even when displaying information on the glass panel in vehicles with a small angle between the windshield and the horizontal plane. The ratio T / M can be 1.35 or lower, 1.30 or lower, or 1.28 or lower. The optimal ratio T / M can be selected based on the angle of the windshield installation and the installation angle and position of the irradiator used for displaying information.

[0124] In one embodiment of the present invention, the wedge-shaped glass 500 preferably has short sides 508 and 509 of 600 mm or more. A thickness of 600 mm or more allows it to be used in large vehicles. Furthermore, it can be installed in vehicles where the angle of the windshield relative to the horizontal plane is small. The thickness of the glass can be 800 mm or more, 1000 mm or more, 1200 mm or more, or 1400 mm or more.

[0125] Wedge glass 500 can be used to manufacture laminated glass.

[0126] A method for manufacturing laminated glass according to an embodiment of the present invention includes a step of cutting a sheet glass 100 to obtain wedge-shaped glass. The method for manufacturing laminated glass according to an embodiment of the present invention includes a step of cutting a sheet glass 100 to obtain wedge-shaped glass, and a step of laminating and pressing the wedge-shaped glass with other sheet glass sheets through an interlayer film.

[0127] First, by cutting the sheet glass 100 at a specified location, a wedge-shaped glass with one end thicker than the other in the width direction can be obtained. Then, laminated glass is manufactured by the same process as that used in the manufacturing method of laminated glass using sheet glass manufactured by the above-described method.

[0128] As described above, in the above embodiment, the two ends G2B, G2B in the width direction are heated more intensely in the upstream region of the molten metal bath 21 than the central portion G2A in the width direction of the glass ribbon, and multiple top rollers 23 are rotated such that the circumferential speed of the top roller 23A upstream in the travel direction F1 is slower than the circumferential speed of the top roller 23B downstream. This makes it less likely for the viscosity of the two ends G2B, G2B in the width direction to rise compared to the central portion G2A in the width direction. Furthermore, it widens the width of the glass ribbon that expands on both sides of the rotation axis of the upstream top roller, making it easier for the glass ribbon G2 to expand in the width direction upstream of the molten metal bath 21. This also makes the thickness of the two ends G2B, G2B in the width direction of the glass ribbon G2 thinner and the thickness of the central portion G2A in the width direction thicker.

[0129] Furthermore, the ratio W / N of the distance W between the two sidewalls 27, 27 in the region upstream of the shoulder 27A of the molten metal bath 21 (the distance between the two first walls 27B, 27B) and the distance N between the two sidewalls 27, 27 in the region downstream of the shoulder 27A of the molten metal bath 21 (the distance between the two second walls 27C, 27C) is set to be greater than 1.0 and less than 1.6. Therefore, it is less likely for the molten metal 22 to flow in the upstream direction X1, and it is less likely for the glass strip G2 to reciprocate (sway) in the width direction Y. Therefore, it is possible to suppress the deviation of the wedge angle of the wedge-shaped glass obtained by cutting the sheet glass obtained by the sheet glass manufacturing method of this embodiment.

[0130] Example

[0131] The embodiments of the present invention will be described below. Use Figure 1 (A) and Figure 1 (B) shows the glass manufacturing apparatus 1, which manufactured convex glass 100s of Examples 1 to 15. Examples 1 to 14 are exemplary cases, and Example 15 is a comparative example.

[0132] In Examples 1-15, the distance W between the two sidewalls 27, 27 in the region upstream of the shoulder 27A of the molten metal bath 21 (the distance between the two first walls 27B, 27B), the distance N between the two sidewalls 27, 27 in the region downstream of the shoulder 27A of the molten metal bath 21 (the distance between the two second walls 27C, 27C), and their ratio W / N are shown in Table 1. Examples 1-14 satisfy the above formula "1.0 < W / N ≤ 1.6", while Example 15 does not satisfy the above formula.

[0133] In embodiments 1-15, the position where the first wall 27B connects to the shoulder 27A is relative to the length L from the upstream wall 25 to the downstream wall 26 (refer to...). Figure 1 (B) Positions at which the upstream wall 25 is at a distance from the proportion shown in Table 1. Examples 1-15 satisfy the above condition "positions at which the upstream wall 25 is at a distance of 60% to 75%".

[0134] In Examples 1-15, the position where shoulder 27A connects to the second wall 27C is relative to the length L from upstream wall 25 to downstream wall 26 (see reference). Figure 1 (B) Positions at which the upstream wall 25 is at a distance from the proportion shown in Table 1. Examples 1-15 satisfy the above condition "positions at which the upstream wall 25 is at a distance of 65% to 85%".

[0135] In Examples 1-15, the length L relative to the upstream wall 25 to the downstream wall 26 (refer to...) Figure 1 (B) The temperature and viscosity of the central portion G2A of the glass strip G2 on the molten metal surface at a position 20% away from the upstream wall 25 (0.2L away from the upstream wall 25 in the downstream direction X2) are shown in Table 1. Examples 1 to 15 satisfy the above condition "viscosity is 10^(4.5)(dPa·sec) or higher". Moreover, Examples 1 to 15 satisfy the above condition "viscosity is 10^(6.0)(dPa·sec) or lower".

[0136] In Examples 1-15, the length L relative to the upstream wall 25 to the downstream wall 26 (refer to...) Figure 1 (B) The temperature I and viscosity of the central portion G2A of the glass strip G2 on the molten metal surface at a position 32% away from the upstream wall 25 (0.32L away from the upstream wall 25 in the downstream direction X2) are shown in Table 1. Examples 1 to 15 satisfy the above condition "viscosity above 10^(4.7)(dPa·sec)". Moreover, Examples 1 to 15 satisfy the above condition "viscosity below 10^(6.3)(dPa·sec)".

[0137] In Examples 1-15, the length L relative to the upstream wall 25 to the downstream wall 26 (refer to...) Figure 1(B) The temperatures K at both ends of the molten metal 22 in the width direction at a position 32% away from the upstream wall 25 (0.32L away from the upstream wall 25 in the downstream direction X2) are shown in Table 1. Furthermore, the difference (I-K) between the aforementioned temperature I and temperature K is shown in Table 1. Examples 1-14 satisfy the condition "(I-K) is below 62°C".

[0138] In Examples 1-14, the maximum width c, the downstream width b, and the ratio c / b of the glass strip G2 in the width direction Y of the molten metal bath 21 are shown in Table 1. Examples 1-14 satisfy the above condition "1.4≤c / b≤2.2".

[0139] In Examples 1-14, the width a of the glass strip G2 located at a position 35% away from the upstream wall 25 (0.35L away from the upstream wall 25 along the downstream direction X2) relative to the length L from the upstream wall 25 to the downstream wall 26, the minimum width b of the glass strip G2 in the width direction Y of the molten metal bath 21, and their ratio a / b are shown in Table 1. Examples 1-14 satisfy the above condition "1.0≤a / b≤1.9".

[0140] In Examples 1-14, at a position 20% away from the upstream wall 25 (0.2L away from the upstream wall 25 along the downstream direction X2) relative to the length L from the upstream wall 25 to the downstream wall 26, the length A (not shown), the length B (not shown), the length of the molten metal surface not covered by the glass strip G2 in the width direction Y, and their ratio A / B are shown in Table 1. Examples 1-14 satisfy the above condition "4≤A / B≤11".

[0141] Table 1

[0142]

[0143] In Examples 1-15, top rollers 23 are arranged at both ends of the molten metal bath 21 in the width direction Y. The traveling speed V (m / h) of the glass belt G2 in the annealing section 30 is shown in Table 2.

[0144] In addition, Table 2 also shows the maximum value T (mm) and minimum value M (mm) of the thickness of the plate glass (convex glass) obtained under the above manufacturing conditions, the thickness t, difference (T-M) (mm) of the central part G2A of the glass strip G2 in the width direction in the annealing section 30, and the ratio T / M.

[0145] Table 2

[0146]

[0147] The angle α of the convex glass in Examples 1-15 obtained under the above manufacturing conditions (refer to...) Figure 5(B) is shown in Table 1. In all Examples 1 to 14 except Example 15, the angle α is within a suitable range of 0.020° to 0.050°.

[0148] Furthermore, in all Examples 1-15, the maximum distance (swing amplitude) of movement in the width direction Y within 30 minutes at the location where the glass strip G2 was cut was less than 1.5 inches, and was suppressed to a very small value. However, in Example 15, when the maximum distance (swing amplitude) of movement in the width direction Y within 30 minutes at the location where the glass strip G2 was cut was suppressed to less than 1.5 inches, the angle α was 0.017°, and the angle α could not reach more than 0.020°. In Example 15, in order to manufacture convex glass with an angle α of more than 0.020°, it was necessary to increase the viscosity of the glass strip G2, and therefore the swing amplitude became more than 2.0 inches.

[0149] The preferred embodiments of the manufacturing method of the convex plate glass of the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0150] In the melting section 10, the glass raw material is melted into molten glass G1 using a melting furnace 11. However, it is preferable to use a metal detector to remove the stainless steel contained in the glass raw material before adding it to the melting furnace 11. Stainless steel contains iron, nickel, chromium, etc. Conventional metal detectors can distinguish between metals and non-metals, but they cannot arbitrarily distinguish only stainless steel. Therefore, when removing stainless steel from the glass raw material, the iron required for melting the glass raw material is also removed. The metal detector used to remove stainless steel has a coil, and the magnetic field generated by the coil distinguishes between stainless steel and iron. Iron is magnetized by the alternating magnetic field emitted by the transmitting coil. The magnetic lines of force are attracted to the iron, and the iron can be detected by detecting them with a receiving coil of a differential structure. In addition, the alternating magnetic field emitted by the transmitting coil generates eddy currents in the stainless steel, thereby generating a magnetic field near the stainless steel. Stainless steel can be detected by detecting the change in this magnetic field with a receiving coil of a differential structure. The phase of the eddy current generated in the stainless steel is delayed by about 90° compared with the phase of the transmitting coil, so stainless steel and iron can be distinguished by detecting the phase angle. The phase angle of iron is 40–80°, while that of stainless steel is 140–180°. The larger the eddy current amplitude generated by stainless steel, the larger the size of the stainless steel. A metal detector is installed, for example, on a conveyor belt that transports the mixed glass raw material to the melting furnace 11. The metal detector preferably has a mechanism that removes 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, the metal detector inputs two analog signals, X and Y, to the PLC (Programmable Logic Controller) to calculate the phase angle and the maximum voltage. When the phase angle is 140–180° (indicating stainless steel) and the maximum voltage is above a preset value, a baffle installed on the conveyor belt opens, removing the glass raw material containing stainless steel of a specific size or larger from the conveyor belt to prevent stainless steel from entering the melting furnace 11.

[0151] Furthermore, this application is based on Japanese Patent Application No. 2021-141551, filed on August 31, 2021, the contents of which are incorporated herein by reference.

[0152] Symbol Explanation

[0153] 1 Glass manufacturing apparatus

[0154] 10 Melting Section

[0155] 11. Melting furnace

[0156] 12 gates

[0157] 13. Lips

[0158] 20 Forming section

[0159] 21 Molten Metal Bath

[0160] 21U upstream end

[0161] 22 Molten metal

[0162] 23, 23A, 23B Top Rollers

[0163] 24 Heaters

[0164] 24A Central Heater

[0165] 24B End Heater

[0166] 25. Upstream wall

[0167] 26 Downstream wall

[0168] 27 Sidewalls

[0169] 27A Shoulder

[0170] 27B First Wall

[0171] 27C Second Wall

[0172] 30 Annealing section

[0173] 31 Annealing Chamber

[0174] 32 Conveyor Rollers

[0175] 100 Convex Glass (Plate Glass)

[0176] 200 wedge glass

[0177] 300 Front Window

[0178] 301, 302 Wedge-shaped glass

[0179] 303 Intermediate Membrane

[0180] 400 Front Window

[0181] 401 wedge glass

[0182] 402 glass

[0183] 403 Intermediate Membrane

[0184] 500 wedge glass

[0185] 507 Convex

[0186] 503 line segment

[0187] 504 Intersection (First Point)

[0188] 505 intersection

[0189] 506 Second point.

Claims

1. A method for manufacturing plate glass, comprising: floating a glass ribbon on the surface of molten metal in a molten metal bath; and abutting multiple top rollers against both ends of the glass ribbon in the width direction to form the glass ribbon into a plate-shaped plate glass, wherein... The molten metal bath has an upstream wall, a downstream wall, and two side walls. The two sidewalls each include shoulders that reduce the width of the molten metal bath in the direction of travel of the glass ribbon. The ratio W / N of the distance W between the two sidewalls in the region upstream of the shoulder of the molten metal bath to the distance N between the two sidewalls in the region downstream of the shoulder of the molten metal bath is greater than 1.0 and less than 1.

6. By heating the two ends in the width direction to a greater degree than the central portion in the width direction of the glass strip in the upstream region of the molten metal bath, a plate glass with a central portion in the width direction that is thicker than the two ends is manufactured.

2. The method for manufacturing plate glass as described in claim 1, wherein, The glass strip is heated at a position 20% of the length from the upstream wall to the downstream wall, such that the viscosity of the central portion of the glass strip in the width direction on the molten metal surface is above 10^4.5 dPa·sec.

3. The method for manufacturing plate glass as described in claim 1 or 2, wherein, The glass strip is heated at a position 20% of the length from the upstream wall to the downstream wall, such that the viscosity of the central portion of the glass strip in the width direction on the molten metal surface is below 10^6.0 dPa·sec.

4. The method for manufacturing plate glass as described in claim 1 or 2, wherein, At a position 32% of the distance from the upstream wall to the downstream wall, the temperature difference between the central portion of the glass strip on the molten metal surface in the width direction and the temperatures at both ends of the molten metal in the width direction is less than 62°C.

5. The method for manufacturing plate glass as described in claim 1 or 2, wherein, The glass ribbon is heated at a position 32% of the length from the upstream wall to the downstream wall, such that the viscosity of the central portion of the glass ribbon in the width direction on the molten metal surface is above 10^4.7 dPa·sec.

6. The method for manufacturing plate glass as described in claim 1 or 2, wherein, The glass ribbon is heated at a position 32% of the length from the upstream wall to the downstream wall, such that the viscosity of the central portion of the glass ribbon in the width direction on the molten metal surface is below 10^6.3 dPa·sec.

7. The method for manufacturing plate glass as described in claim 1 or 2, wherein, The ratio of the maximum width of the glass strip in the molten metal bath in the width direction to the length of the downstream glass strip in the width direction is 1.4 to 2.

2.

8. The method for manufacturing plate glass as described in claim 1 or 2, wherein, At a position 35% of the distance from the upstream wall relative to the length from the upstream wall to the downstream wall, the ratio a / b of the width a of the glass strip to the length b of the downstreammost glass strip in the width direction of the molten metal bath is 1.0 to 1.

9.

9. The method for manufacturing plate glass as described in claim 1 or 2, wherein, At a position 20% of the distance from the upstream wall relative to the length from the upstream wall to the downstream wall, the ratio A / B of the length A in the width direction of the glass strip to the length B in the width direction of the molten metal surface not covered by the glass strip is 4 to 11.

10. A method for manufacturing wedge-shaped glass, wherein wedge-shaped glass is obtained by cutting a plate glass obtained by the plate glass manufacturing method according to any one of claims 1 to 9.

11. The method for manufacturing wedge-shaped glass as described in claim 10, wherein, At least one main surface of the wedge-shaped glass is convex. On a line segment connecting two opposing sides of the four sides of the convex surface with the shortest distance through the centroid G of the convex surface, the point where the wedge-shaped glass has a smaller thickness in the vertical direction when the wedge-shaped glass is placed in a horizontal location is taken as the first point. The point on the convex surface at a position where the length of the distance from the first point is 2 / 5 of the length of the line segment is taken as the second point. Then the angle between the straight line connecting the first point and the second point and the horizontal plane is 0.020° to 0.050°.

12. The method for manufacturing wedge-shaped glass as described in claim 10 or 11, wherein, The ratio of the maximum thickness T to the minimum thickness M of the wedge-shaped glass, T / M, is 1.10 to 1.

40.

13. A method for manufacturing laminated glass, wherein, The plate glass obtained by the method for manufacturing plate glass according to any one of claims 1 to 9 is cut to obtain wedge-shaped glass, and The wedge-shaped glass is stacked and pressed together with other plate glass through an interlayer film.

14. The method for manufacturing laminated glass as described in claim 13, wherein, The other glass plates are the wedge-shaped glass.

15. The method for manufacturing laminated glass as described in claim 14, wherein, The other glass panels are glass panels with a fixed thickness.

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