Methods for manufacturing sheet glass, apparatus for manufacturing sheet glass, and sheet glass

Abstract

The manufacturing method of the plate glass (G) includes a breaking process. This breaking process is applied to a plate glass (G) in a longitudinal orientation where a first region (G1) and a second region (G2) are arranged adjacently in the width direction and have scribe lines (S) formed on the surface (Ga, Gx) side of the boundary portion of these regions (G1, G2). With the first region (G1) supported by a back support member (3) from the back side (Gb), a force is applied to the second region (G2) towards the back side (Gy), thereby breaking the plate glass (G) along the scribe lines (S) and cutting out the second region (G2). In the breaking process, by bringing the first region (G1) into contact with the back support member (3), a curved portion (Gws) that convexes along the vertical direction is formed in the region (Gs) where the scribe lines (S) are formed.

Description

Technical Field

[0001] This invention relates to an improvement in the manufacturing technology of sheet glass, including a technique for breaking sheet glass along a scribed line. Background Technology

[0002] As is well known, sheet glass is used in various fields, such as as glass substrates for displays like liquid crystal displays, plasma displays, and organic EL displays, and as cover glass for organic EL lighting. The manufacturing process of such sheet glass involves steps such as sequentially cutting sheet glass of a specified length from a glass strip, and removing unwanted areas along the edges of the sheet glass. In these steps, after the glass strip and sheet glass have been etched with grooves, they are broken along these grooves to obtain the desired sheet glass.

[0003] As a specific example of a method for obtaining sheet glass by breaking, the method disclosed in Patent Document 1 can be cited. In the method disclosed in this document, with a scribe line formed on the surface side of the boundary between a first region and a second region arranged adjacent to each other in the width direction of the sheet glass, and the first region being supported from the back side by a back support member, a rotating body is used to press the second region towards the back side. This breaks the sheet glass along the scribe line and cuts out the second region. The breaking is performed by supporting the sheet glass in a longitudinal position.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2017-226549 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] As disclosed in Patent Document 1, if a glass pane is supported in a longitudinal orientation, longitudinal warping can occur. This warping has become more pronounced in recent years with the thinning of glass panes (e.g., those used in displays). In the method disclosed in Patent Document 1, the following problem occurs when such a glass pane is broken.

[0009] That is, the longitudinal warping shape of the glass pane is inconsistent, so when the back support member contacts and supports the first region of the glass pane from the back side, the contact state between the two is not consistently determined in the vertical direction. Affected by this contact state, the shape of the area where the scribe lines form is also not consistently determined in the vertical direction. Therefore, during the process of pressing the second region towards the back side by bringing the two into contact, it is difficult to consistently apply appropriate bending stress to the area where the scribe lines form. As a result, when the glass pane is broken, it is prone to chipping, cracking, etc.

[0010] Based on the above viewpoints, the objective of this invention is to suppress the occurrence of chipping, cracking, etc., by consistently applying appropriate bending stress to the area where the scribe lines are formed when using a back support member to break a sheet of glass in a longitudinal orientation.

[0011] Solution for solving the problem

[0012] The first aspect of the present invention, made to solve the above-mentioned problems, is a method for manufacturing a sheet glass, including a breaking process. The breaking process is for a sheet glass in a longitudinal orientation where a first region and a second region are arranged adjacent to each other in the width direction and have scribed lines formed on the surface side of the boundary of these regions. While the first region is supported from the back side by a back support member, a force is applied to the second region toward the back side, thereby breaking the sheet glass along the scribed lines and cutting out the second region. The method for manufacturing the sheet glass is characterized in that, in the breaking process, by contacting the first region with the back support member, a curved portion with a convex surface side along the vertical direction is formed in the region where the scribed lines are formed.

[0013] Here, the area where the scribe line is formed (hereinafter referred to as the scribe line forming area) means the part of the glass plate where the scribe line is formed and its surrounding area. For example, it means the area between two parts that are separated by 50 to 100 mm from the scribe line in the width direction (hereinafter the same).

[0014] According to this method, when breaking a longitudinally oriented sheet glass in the breaking process, a curved portion is forcibly formed in the scribe line forming area by bringing the first region into contact with the back support member. Specifically, a curved portion bending in the vertical direction is forcibly formed in the scribe line forming area in a manner that the surface side becomes convex. By forcibly forming the curved portion, the shape of the scribe line forming area during breaking is consistently determined. Furthermore, with the aforementioned curved portion formed in the scribe line forming area, when a force is applied to the second region toward the back side, a bending stress greater than that in other areas is consistently applied to the top periphery of the curved portion in the scribe line forming area. As a result, when the sheet glass is broken, the action of generating cracks in the scribe lines and allowing these cracks to propagate can be appropriately performed. Consequently, deviations in the cutting position and poor cutting are less likely to occur when the sheet glass is broken, and the occurrence of shattering and cracking is suppressed.

[0015] In this method, the back support member may also have a central convex portion for forming a curved portion along the vertical direction at the middle of the vertical direction of the area where the scribed line is formed.

[0016] In this way, when the first region comes into contact with the back support member, due to the presence of the central protrusion of the back support member, a curved portion with a convex surface along the vertical direction is formed in the middle portion of the scribed line forming region. In this state, when a force is applied to the second region towards the back side, a greater bending stress can be applied to the middle portion of the scribed line forming region in the vertical direction than to other parts. As a result, when the glass plate breaks, a crack can be generated in the middle portion of the scribed line in the vertical direction, and the crack can extend appropriately in both the vertical and horizontal directions. Thus, the occurrence of chipping, breakage, etc., can be more reliably suppressed.

[0017] In this method, the intermediate protrusion may be bent in such a way that its protruding length gradually shortens from the central part in the vertical direction toward both ends.

[0018] In this way, since the shape of the central protrusion becomes a smoothly curved shape, the curved portion formed in the middle of the vertical direction of the scribed line forming area also becomes a smoothly curved shape when the first region comes into contact with the back support member. Therefore, it is possible to further and more appropriately break the sheet glass.

[0019] Alternatively, in this method, the intermediate protrusion may be disposed at a position that does not overlap with the retaining member holding the upper end of the first region in the vertical direction.

[0020] In this way, undue stress on the upper periphery of the first region can be suppressed. Specifically, the upper end of the first region is sometimes held by a retaining member and becomes a planar portion. In this case, assuming the middle protrusion overlaps with the retaining member in the vertical direction, the curved portion in the middle of the first region in the vertical direction interferes with the aforementioned planar portion, thus potentially causing undue stress such as torsion on the upper periphery of the first region. With this structure, such an undesirable situation can be avoided.

[0021] In the above method, it is also possible that, during the breaking process, the pressing member disposed on the surface side of the first region presses the first region against the back support member.

[0022] In this way, the first region is held between the pressing member and the back support member, thus suppressing wobbling of the glass plate when a bend is formed in the scribed line forming area. This stabilizes the contact between the first region and the back support member.

[0023] Alternatively, the pressing member may have an upper protrusion for forming a planar portion at the upper end of the area where the scribed line is formed.

[0024] In this way, when the pressing member presses the first region against the back support member, a planar portion is formed at the upper end of the area where the scribe line is formed by the upper protrusion of the pressing member. As a result, the pressing by the pressing member becomes reliable. Consequently, the contact state between the first region and the back support member can be stabilized more reliably.

[0025] In this method, the upper protrusion may also be disposed at a position that overlaps with the retaining member holding the upper end of the first region in the vertical direction.

[0026] In this way, the planar portion formed in the first region by the clamping of the upper protrusion of the pressing member and the back support member, and the planar portion formed in the first region by the holding member, are arranged along the width direction at the upper end of the first region. As a result, it is possible to more reliably suppress undue stress on the periphery of the upper end of the first region.

[0027] In this method, the back support member may have a central protrusion for forming a curved portion along the vertical direction at the middle of the vertical direction of the area where the scribed line is formed, and the upper protrusion is disposed at a position that does not overlap with the central protrusion in the vertical direction.

[0028] In this way, interference can be avoided between the planar portion formed at the upper end of the first region by the clamping of the upper protrusion of the pressing member and the back support member, and the curved portion formed at the middle vertical direction of the first region by the clamping of the middle protrusion of the back support member and the pressing member. As a result, undue stress on the periphery of the upper end and the middle vertical direction of the first region can be suppressed.

[0029] Alternatively, the pressing member may have a lower convex portion for forming a planar portion at the lower end of the area where the scribed line is formed.

[0030] In this way, when the pressing member presses the first region against the back support member, a planar portion is formed at the lower end of the area where the scribe line is formed by the lower protrusion of the pressing member. This makes the pressing by the pressing member reliable. As a result, the contact state between the first region and the back support member can be stabilized more reliably.

[0031] In this method, the back support member may have a central protrusion for forming a curved portion along the vertical direction at the middle of the vertical direction of the area where the scribed line is formed, and the lower protrusion is disposed at a position that does not overlap with the central protrusion in the vertical direction.

[0032] In this way, interference can be avoided between the planar portion formed at the lower end of the first region by the clamping of the lower protrusion of the pressing member and the back support member, and the curved portion formed at the middle vertical direction of the first region by the clamping of the middle protrusion of the back support member and the pressing member. As a result, undue stress on the lower end and the middle vertical direction of the first region can be suppressed.

[0033] A second aspect of the present invention, made to solve the aforementioned problems, is a manufacturing apparatus for sheet glass, comprising a breaking device configured to, for a sheet glass in a longitudinal orientation in which a first region and a second region are arranged adjacent to each other in the width direction and in which scribe lines are formed on the surface side of the boundary of these regions, while the first region is supported from the back side by a back support member, apply a force toward the back side to the second region, thereby breaking the sheet glass along the scribe lines and cutting out the second region. The manufacturing apparatus for sheet glass is characterized in that the breaking device is configured to form a curved portion in the vertical direction with a convex surface side in the region where the scribe lines are formed by contacting the first region with the back support member.

[0034] According to this scheme, the same effects as the described manufacturing method, which is substantially the same as the manufacturing apparatus, can be obtained.

[0035] A third aspect of the present invention, made to address the aforementioned problems, is a plate glass having a rectangular shape with two first sides extending along a first direction and two second sides extending in a direction different from the first direction. The plate glass is characterized by having a plurality of stripes extending along the first direction on its surface and / or back surface, and a crack origin within at least one of the first sides, extending from one end toward the other for a range of 25% to 75% of the total length of that first side. Here, the crack origin refers to the point of failure of the crack.

[0036] According to this structure, a crack origin is located within a defined range at the center of the length direction of the glass pane. Therefore, when the glass pane is cut, the crack propagates from the center of the length direction towards both ends. In other words, a crack propagation starting point (crack origin) is formed at the center of the length direction of the glass pane, and the crack smoothly propagates towards both ends along the length direction from this starting point. Therefore, the glass pane is properly cut, and the adhesion of glass dust to the glass pane caused by poor cutting is prevented, resulting in high quality.

[0037] Invention Effects

[0038] According to the present invention, when a longitudinally oriented sheet glass is broken using a back support member, appropriate bending stress can be applied consistently to the area where the scribe line is formed, thereby suppressing the occurrence of chipping, cracking, etc. Attached Figure Description

[0039] Figure 1 This is a perspective view showing the main part of the cutting device included in the glass manufacturing apparatus according to an embodiment of the present invention.

[0040] Figure 2 According to Figure 1 The longitudinal section side view obtained by cutting along the BB line.

[0041] Figure 3 This is a perspective view illustrating the function of the cutting device included in the glass manufacturing apparatus according to an embodiment of the present invention.

[0042] Figure 4 According to Figure 3 The longitudinal section side view obtained by cutting along the CC line.

[0043] Figure 5 This is a longitudinal sectional side view showing the main part of the cutting device included in the glass manufacturing apparatus according to an embodiment of the present invention.

[0044] Figure 6a This is a cross-sectional bottom view showing the main part of the step of breaking the sheet glass by the cutting device included in the sheet glass manufacturing apparatus using an embodiment of the present invention in a time sequence.

[0045] Figure 6b This is a cross-sectional bottom view showing the main part of the step of breaking the sheet glass by the cutting device included in the sheet glass manufacturing apparatus using an embodiment of the present invention in a time sequence.

[0046] Figure 6c This is a cross-sectional bottom view showing the main part of the step of breaking the sheet glass by the cutting device included in the sheet glass manufacturing apparatus using an embodiment of the present invention in a time sequence.

[0047] Figure 7 This is a cross-sectional bottom view of the main part of the overall structure of the cutting device included in the glass manufacturing apparatus according to an embodiment of the present invention.

[0048] Figure 8 This is a schematic perspective view of a glass plate according to an embodiment of the present invention. Detailed Implementation

[0049] Hereinafter, the manufacturing method and manufacturing apparatus for sheet glass according to embodiments of the present invention, as well as the sheet glass itself, will be described with reference to the accompanying drawings.

[0050] Figure 1The following figure illustrates a breaking device 1 included in a glass manufacturing apparatus according to an embodiment of the present invention. As shown, the glass plate G has a first region G1 and a second region G2 arranged adjacent to each other in the width direction. In this embodiment, the first region G1 is the region of the glass plate G that becomes a product, and its thickness is uniform throughout the entire region. The second region G2 is the region cut from the glass plate G and discarded, and has an ear Ge at its outer end in the width direction (left end in the example) that is thicker than the first region G1. Grating lines S are formed on the surfaces Ga and Gx at the boundary between the first region G1 and the second region G2. In the example, the grading lines S do not reach the upper and lower ends of the glass plate G. It should be noted that the grading lines S may also reach these upper and lower ends. In the following description, for convenience, the first region G1 will be referred to as the effective region, and the second region G2 will be referred to as the unwanted region. Additionally, although not shown, multiple stripes extending in the vertical direction are formed on the surfaces Ga and Gx and / or the back surfaces Gb and Gy of the glass plate G. It should be noted that these stripes are formed along the pulling direction when the plate glass G is manufactured, for example, using an overflow method. Furthermore, these stripes can be observed as a striped pattern by adjusting the angle of the plate glass G in a darkroom while irradiating light from a light source (e.g., a xenon lamp) and projecting the light onto a screen.

[0051] The glass plate G is suspended longitudinally with the scribed lines S pointing vertically. The thickness of the glass plate G (excluding the ear portion Ge) is, for example, 50 to 2000 μm, but the upper limit of this thickness is preferably 500 μm, more preferably 400 μm. In this embodiment, the glass plate G is flexible. Longitudinal warping occurs in the glass plate G. The specific shape of the warping is the shape of the scribed lines S in the surface Ga and Gx of the glass plate G, as well as any imaginary straight line parallel to the scribed lines S. Furthermore, the shape of the longitudinal warping of the glass plate G is not consistent, but rather becomes a random shape.

[0052] The breaking device 1 breaks the glass plate G along the scribed line S to remove the unwanted area G2. Specifically, the breaking device 1 includes: a holding mechanism 2 that holds the upper end of the effective area G1; a back support member 3 disposed on the back side Gb of the effective area G1; a pressing member 4 disposed opposite to the back support member 3 on the surface Ga side of the effective area G1; an adsorption mechanism 5 disposed on the back side Gy of the unwanted area G2; and a pressing member 6 disposed opposite to the adsorption mechanism 5 on the surface Gx side of the unwanted area G2.

[0053] The gripping mechanism 2 has a pair of gripping plates 2a and a drive unit 2b that brings the pair of gripping plates 2a closer together and further apart. The structure of the drive unit 2b is not limited to the structure shown in the figure. The pair of gripping plates 2a grips the upper end of the effective area G1 by approaching each other to become a closed state, and releases the grip on the upper end of the effective area G1 by moving further apart to become an open state. It should be noted that the pair of gripping plates 2a can also be structured to become an open state by spreading their legs and to become a closed state by closing their legs. Here, spreading their legs means that the pair of gripping plates 2a rotates about a fulcrum (axis) in the opening direction, and closing their legs means that the pair of gripping plates 2a rotates about a fulcrum (axis) in the closing direction.

[0054] The holding mechanism 2 is slidably held on a guide rail (not shown) extending along the width direction above the glass plate G, and serves to transport the glass plate G towards the breakage position. When the glass plate G is broken at the breakage position, the holding mechanism 2 stops while holding the upper end of the effective area G1. In this case, the lower end of the glass plate G is not held but left open. It should be noted that the holding mechanism 2 holds multiple portions in the width direction of the upper end of the effective area G1 (two portions in this embodiment (one portion is not shown)).

[0055] When the glass plate G breaks, the back support member 3 contacts the effective support area G1 from the back side Gb side and is positioned at the end of the effective area G1 on the side of the scribe line S. The back support member 3 moves closer to and further away from the back side Gb of the effective area G1 by the action of a hydraulic cylinder, ball screw mechanism, or robotic arm (not shown). The back support member 3 is a columnar or plate-like body (platform) that is relatively long in the vertical direction. The separation distance between the back support member 3 and the scribe line S in the width direction (the separation distance when the back support member 3 contacts the effective area G1) is, for example, 10 to 30 mm, preferably 10 to 20 mm. In the illustration, the back support member 3 extends from the upper and lower ends of the effective area G1, but it may not extend from these ends.

[0056] When the glass plate G breaks, the pressing member 4 presses the effective area G1 against the back support member 3. The pressing member 4 moves closer to and further away from the surface Ga of the effective area G1 by means of a hydraulic cylinder (such as a pneumatic cylinder), a ball screw mechanism, or a robotic arm (not shown). In this embodiment, the pressing member 4 is a columnar or plate-like body that is relatively long in the vertical direction. It should be noted that the vertical length of the pressing member 4 is the same as that already described regarding the back support member 3.

[0057] The adsorption mechanism 5 includes: a holding base 5a, which is longer in the vertical direction; and adsorption pads 5b, which are respectively mounted on the upper and lower ends of the holding base 5a. The holding base 5a is rotated (e.g., in the direction of arrow A) by the action of a drive mechanism such as a robotic arm. The adsorption pads 5b use negative pressure adsorption to hold the back side Gy of the unwanted area G2 and are formed of an elastic member such as stretchable rubber or resin. The upper adsorption pad 5b is positioned at the same height as the holding piece 2a at the upper end of the effective holding area G1. The lower adsorption pad 5b is positioned at a lower position separated from the upper adsorption pad 5b by the same length as the center of the vertical direction of the glass plate G. More than three adsorption pads 5b can be arranged along the vertical direction of the holding base 5a, but in practice, only two adsorption pads arranged in the same position as in the illustration are used for adsorption and holding of the back side Gy of the unwanted area G2.

[0058] The press-in member 6 has a flat portion 6a that contacts the surface Gx of the unwanted area G2 (see reference). Figure 5 In this embodiment, the pressing member 6 is a plate-shaped structure that is longer in the vertical direction. The pressing member 6 is rotated (e.g., in the direction of arrow A) by the action of a drive mechanism such as a robotic arm (not shown), thereby applying a pressing force toward the back side Gy to the unwanted region G2. In the illustration, the pressing member 6 extends from the upper and lower ends of the unwanted region G2, but it may not extend from these upper and lower ends.

[0059] Figure 2 According to Figure 1 The figure shows a longitudinal sectional side view obtained by cutting along the BB line. As shown in the figure, the back support member 3 has a central protrusion 7 at the central part of the opposing portion 3x in the vertical direction, which is opposite to the back surface Gb of the plate glass G (effective area G1). In detail, the back support member 3 has a columnar or plate-shaped support substrate 3y. A central protrusion 7 with a curved surface is fixedly provided on the surface of the support substrate 3y. The central protrusion 7 is smoothly curved in such a way that its protruding length gradually shortens from the central side in the vertical direction to both ends. The central protrusion 7 serves to form a curved portion Gw (details described later) in the vertical direction at the central part of the scribe line forming area Gs, where the surfaces Ga and Gx become convex.

[0060] The vertical length of the intermediate protrusion 7 is 1 / 4 to 3 / 4 of the vertical length of the glass plate G. The intermediate protrusion 7 is positioned at a location that does not overlap vertically with the gripping piece 2a at the upper end of the effective gripping area G1. That is, the upper end 7x of the intermediate protrusion 7 is located below the lower end 2y of the gripping piece 2a. The lower end 7y of the intermediate protrusion 7 is located at a position that is separated downward from the center of the vertical direction of the glass plate G by the same length as the upper end 7x of the intermediate protrusion 7. The intermediate protrusion 7 is softer than the glass plate G and the supporting substrate 3y and is superior in terms of elasticity or cushioning. For example, it is formed of porous resin or foamed resin, such as plastic corrugated paper or PP foam board, or FC nylon. A covering sheet 8 is attached to the surface of the supporting substrate 3y and the intermediate protrusion 7 to cover them. This covering sheet 8 is softer than the intermediate protrusion 7 and is formed of porous resin or foamed resin, such as sponge or low-resilience sponge.

[0061] The pressing member 4 has an upper protrusion 9 at its upper end of the opposing portion 4x, which faces the surface Ga of the plate glass G (effective area G1), and a lower protrusion 10 at its lower end. Specifically, the pressing member 4 has a columnar or plate-shaped support substrate 4y. The upper protrusion 9 and the lower protrusion 10 are fixedly provided at both the upper and lower portions of the surface of the support substrate 4y. Both the upper protrusion 9 and the lower protrusion 10 are wedge-shaped, with their protruding length gradually increasing from the center side towards both ends in the vertical direction of the support substrate 4y. The upper protrusion 9 and the lower protrusion 10 serve to form an upper planar portion Gcs and a lower planar portion Gds (details described later) at the upper and lower ends of the scribing line forming area GS, respectively.

[0062] Both the upper protrusion 9 and the lower protrusion 10 are positioned where they do not overlap with the middle protrusion 7 of the back support member 3 in the vertical direction. Specifically, the lower end 9y of the upper protrusion 9 is positioned above the upper end 7x of the middle protrusion 7, and the upper end 10x of the lower protrusion 10 is positioned below the lower end 7y of the middle protrusion 7. Furthermore, the upper protrusion 9 is positioned where it overlaps with the gripping piece 2a at the upper end of the effective gripping area G1 in the vertical direction. Specifically, the upper end 9x of the upper protrusion 9 is positioned above the upper end 2x of the gripping piece 2a, and the lower end 9y of the upper protrusion 9 is positioned below the lower end 2y of the gripping piece 2a. It should be noted that the upper protrusion 9 may also be positioned where it only partially overlaps with the gripping piece 2a in the vertical direction. In this embodiment, the upper end 9x of the upper protrusion 9 and the lower end 10y of the lower protrusion 10 are located at the same height as the upper and lower ends of the glass plate G, respectively. However, these protrusions 9 and 10 may or may not extend from the upper and lower ends of the glass plate G. The upper protrusion 9 and the lower protrusion 10 are both softer than the glass plate G and the supporting substrate 4y and are superior in terms of elasticity or cushioning. For example, they are formed of porous resins or foamed resins, such as plastic corrugated paper or PP foam board, or FC nylon. A covering sheet 11 is attached to the surface of the supporting substrate 4y, the upper protrusion 9, and the lower protrusion 10 to cover them. This covering sheet 11 is softer than the upper protrusion 9 and the lower protrusion 10 and is formed of porous resins or foamed resins, such as sponge or low-resilience sponge.

[0063] Next, the manufacturing method of plate glass using the manufacturing apparatus configured as described above will be explained.

[0064] First, in comparison Figure 1 In the upstream process shown, while the glass plate G is suspended and supported by the holding mechanism 2, scribing lines S are formed on the glass plate G using methods such as pressing with a cutting wheel and laser irradiation. Specifically, scribing lines S are formed on the surfaces Ga and Gx of the boundary between the effective area G1 and the unwanted area G2 of the glass plate G. Next, the glass plate G with the scribing lines S formed is transported along the width direction while still suspended and supported by the holding mechanism 2, thereby bringing the glass plate G to... Figure 1 The breakage position is shown. At this moment, the pressing member 4 and the back support member 3 separate from the surface Ga and back surface Gb of the effective area G1, respectively, and the pressing member 6 and the adsorption mechanism 5 also separate from the surface Gx and back surface Gy of the unwanted area G2, respectively. In this state, longitudinal warping occurs in the glass plate G.

[0065] Subsequently, the back support member 3 moves toward the effective area G1, and the pressing member 4 also moves toward the effective area G1. At the moment when both the back support member 3 and the pressing member 4 have completed their movements, the pressing member 4 presses the effective area G1 toward the back support member 3. Thus, as... Figure 3 As shown, a curved portion Gw is formed in the pressed area (hereinafter referred to as the pressing area) of the effective area G1 (see details). Figure 4 Along with this, a curved portion Gws is also formed in the scribing area Gs. Specifically, curved portions Gw and Gws, with surfaces Ga and Gx respectively becoming convex on the vertical direction, are formed in the pressing part and the vertical center of the scribing area Gs. In this embodiment, the same curved portion Gwt is also formed in the vertical center of the unwanted area G2, and the same curved portion Gwu is also formed in the vertical center of the peripheral area of ​​the gripping part held by the gripping piece 2a in the effective area G1. In addition, when the pressing member 4 presses the effective area G1 against the back support member 3, an upper planar portion Gc and a lower planar portion Gd are formed at the upper and lower ends of the pressing part, respectively (see details). Figure 4 Along with this, an upper planar portion Gcs and a lower planar portion Gds are formed at the upper and lower ends of the scribe line forming region Gs, respectively. In this embodiment, the same upper planar portion Gct and lower planar portion Gdt are also formed at the upper and lower ends of the unwanted region G2, and the same upper planar portion Gcu and lower planar portion Gdu are also formed at the upper and lower ends of the peripheral region of the gripping part held by the gripping piece 2a in the effective region G1.

[0066] Figure 4 According to Figure 3The longitudinal section side is obtained by cutting along the CC line. As shown in the figure, a curved portion Gw is formed in the vertical center of the effective area G1 (pressing part) through contact with the intermediate protrusion 7. Specifically, the curved portion Gw is smoothly curved in such a way that the degree of protrusion towards the surface Ga gradually decreases from the vertical center towards both ends. Accompanying this, the longitudinal warping generated in the vertical center of the effective area G1 disappears. In addition, an upper planar portion Gc and a lower planar portion Gd are formed at the upper and lower ends of the effective area G1 through contact with the upper protrusion 9 and the lower protrusion 10, respectively. Accompanying this, the warping generated at the upper and lower ends of the effective area G1 also disappears. In this case, the lower end of the upper planar portion Gc is at the same height as the lower end 2y of the holding piece 2a. It should be noted that, as shown in the figure, when the effective area G1 is clamped between the back support member 3 and the pressing member 4, the middle protrusion 7 is only slightly compressed and deformed, while the upper protrusion 9, the lower protrusion 10 and the covering pieces 8 and 11 are compressed and deformed significantly.

[0067] In this state, the adsorption mechanism 5 moves toward the unwanted area G2, and the pressing member 6 also moves toward the unwanted area G2. At the moment when the movements of both the adsorption mechanism 5 and the pressing member 6 are completed, as... Figure 5 As shown, the two adsorption pads 5b of the adsorption mechanism 5 adsorb and hold the back surface Gy of the unwanted region G2, and the pressing member 6 contacts the surface Gx of the unwanted region G2. In this case, the two adsorption pads 5b adsorb and hold the upper planar portion Gct and the lower planar portion Gdt of the unwanted region G2. The pressing member 6 contacts the top periphery of the curved portion Gwt formed in the vertical center of the unwanted region G2.

[0068] Figure 6a , Figure 6b as well as Figure 6c The figures shown above illustrate the steps of breaking the glass plate G. All of these figures are cross-sectional bottom views obtained from below, observing the main parts of the breaking device 1 and the main parts of the glass plate G. Figure 6a This illustrates the initial stage of the breaking process, where the scribing lines forming the areas Gs and the unnecessary area G2 of the glass plate G are forcibly shaped as described. From this state, as... Figure 6bAs shown, the adsorption mechanism 5 and the pressing member 6 are rotated in the direction of arrow A, thereby the pressing member 6 exerts a pressing force on the unwanted region G2 towards the back side Gy. As a result, the unwanted region G2 bends towards the back side Gy with the back support member 3 as the fulcrum. It should be noted that the adsorption mechanism 5 does not actually exert a pulling force on the unwanted region G2 towards the back side Gy. During this process, a bending deformation occurs in the width direction of the scribe line forming region Gs, caused by the bending stress acting on the scribe line forming region Gs. In this stage, a bent portion Gw is formed at the center of the scribe line forming region Gs in the vertical direction. Therefore, the maximum bending stress acts at the center of the scribe line forming region Gs in the vertical direction. Then, with further rotation of the adsorption mechanism 5 and the pressing member 6, when the bending stress acting on the scribe line forming region Gs becomes sufficiently large, such as... Figure 6c As shown, the glass plate G breaks along the scribed line S. After the glass plate G is broken and the unwanted area G2 is cut out, the unwanted area G2 is moved to the retracted position while being held by the holding mechanism 2. After that, the holding by the holding mechanism 2 is released and the glass plate is dropped and retrieved.

[0069] The above description focuses on the unwanted region G2 at one end of the glass plate G in the width direction during the breaking device 1 and the breaking process. However, typically, the unwanted region G2 is formed at both ends of the glass plate G in the width direction. To perform breaking of the glass plate G to remove the unwanted region G2, a structure as shown below is adopted. That is, as follows... Figure 7As shown, the central region of the glass plate G in the width direction is the effective region G1, and the two sides of the glass plate G in the width direction are the unwanted regions G2. Gratings S are formed at the two boundaries of the effective region G1 and each unwanted region G2. The glass plate G is broken along these two gradations S by breaking devices 1, each corresponding to one of the unwanted regions G2. Each of the two breaking devices 1 has a pressing member 4 and a back support member 3 respectively disposed on the surface Ga side and the back side Gb side of the effective region G1, and a pressing member 6 and a suction mechanism 5 respectively disposed on the surface Gx side and the back side Gy side of the unwanted region G2. The pressing member 6 and the suction mechanism 5 are both designed to rotate in the direction of arrow A. The detailed structure of the two breaking devices 1 is the same as that of the previously described breaking device 1. In this case, the breaking performed by the two breaking devices 1 can be performed simultaneously, or the breaking performed by the other breaking device 1 can be performed after the breaking performed by one breaking device 1 has been completed. Alternatively, one could arrange the breaking device 1 on one side and the other breaking device 1 at a distance longer than the width of the glass plate G. After using one breaking device 1 to break off and remove the unwanted area G2 on one side, the glass plate G is moved along the width direction, and then the other breaking device 1 is used to break off and remove the unwanted area G2 on the other side. Furthermore, another option is to use only one breaking device 1. After using this breaking device 1 to break off and remove the unwanted area G2 on one side, the glass plate G is rotated 180 degrees in a top view, and then the other unwanted area G2 is broken off and removed using the same breaking device 1.

[0070] Figure 8This is a perspective view showing a rectangular-shaped plate glass G (effective area G1) cut out by this action. As shown in the figure, the plate glass G has two sides 12x extending along a first direction and two sides 12y extending along a direction different from the first direction (orthogonal to the first direction in the illustration). The aforementioned four sides 12x and 12y are the four end faces of the plate glass G. A crack origin D is present on one side (one end face) 12x extending along the first direction, formed by the contact between the pressing member 4 and the intermediate protrusion 7. This crack origin D exists within a range (Lxx) of the total length Lx of this side 12x, extending from one end 12xa towards the other end 12xb, which is more than 25% and less than 75% of the total length Lx of this side 12x. In the illustration, the crack origin D exists only on one side 12x extending along the first direction, but the same crack origin may also exist on the other sides 12x extending along the first direction. This first direction is the direction along the pulling plate direction. Therefore, multiple stripes extending along the first direction exist on one of the surfaces 12za or the other surface 12zb, or both surfaces 12za and 12zb, of the glass plate G. In this embodiment, the crack origin D is formed at one end (the upper end in the illustration) of one of the surfaces 12za of the glass plate G and is located on that edge 12x, and does not reach the other surface 12zb of the glass plate G. Here, the aforementioned surface 12za corresponds to the back surface of the glass plate G (the surface with lower quality than the surface). It should be noted that the crack origin D can be determined or inferred by means of confirmation using an electron microscope, and if confirmation using an electron microscope is not possible, it can be determined or inferred by means of inference based on the rib-like patterns and Vanner lines generated on the glass plate G. For example, the closer to the crack origin D, the narrower the interval between adjacent rib-like patterns. Therefore, the position of the crack origin D can be inferred based on the interval of the rib-like patterns. It should be noted that the crack origin D preferably exists in the range (Lxx) of the edge 12x from one end 12xa toward the other end 12xb, which is more than 30% and less than 70% of the total length Lx of the edge 12x. More preferably, it exists in the range (Lxx) of the edge 12x from one end 12xa toward the other end 12xb, which is more than 35% and less than 65% of the total length Lx of the edge 12x.

[0071] It should be noted that the multiple stripes generated along the direction of the plate can be observed as a striped pattern by adjusting the angle of the plate glass G in the darkroom while irradiating light from a light source (such as a xenon lamp) and projecting the light onto the screen.

[0072] According to the glass manufacturing apparatus of the present invention configured as described above, and the glass manufacturing method using the glass manufacturing apparatus, the following effects are obtained.

[0073] In the above embodiment, when breaking the longitudinally oriented plate glass G in the breaking process, a curved portion Gws is forcibly formed in the scribe line forming region Gs by bringing the effective area G1 into contact with the back support member 3. Through the formation of this forced curved portion Gws, the shape of the scribe line forming region Gs during breaking is consistently determined to be a curved portion Gws with a convex shape on the Ga and Gx sides formed at the center in the vertical direction. In this state, even when a force towards the back side Gy is applied to the unwanted area G2, a bending stress greater than that in other areas can be consistently applied to the center in the vertical direction of the scribe line forming region Gs. Therefore, when the plate glass G is broken, a crack origin can be generated at the center in the vertical direction of the scribe line S, and this crack origin can extend appropriately towards both the vertical and horizontal sides. As a result, deviations in the cutting position and poor cutting are less likely to occur when the plate glass G is broken, and the occurrence of shattering and cracking is suppressed.

[0074] In the above embodiment, during the breaking process, the effective area G1 is clamped by the pressing member 4 and the back support member 3, thus eliminating the shaking of the plate glass G when the curved portion Gws is forcibly formed in the scribe line forming area Gs. This stabilizes the contact state between the effective area G1 and the back support member 3.

[0075] In the above embodiment, the shape of the intermediate protrusion 7 is a smoothly curved shape, so the curved portion Gws formed in the vertical center of the scribing line forming region Gs also becomes a smoothly curved shape, which can further and appropriately break the plate glass.

[0076] In the above embodiment, the intermediate protrusion 7 is disposed at a position that does not overlap with the gripping piece 2a at the upper end of the effective gripping area G1 in the vertical direction, thus suppressing undue stress on the periphery of the upper end of the effective area G1. Specifically, if the intermediate protrusion 7 and the gripping piece 2a were in a vertically overlapping position, the curved portion Gw at the center of the effective area G1 in the vertical direction would interfere with the planar portion (near the reference numeral Gcu) formed by the gripping piece 2a at the upper end of the effective area G1, potentially causing undue stress such as torsion on the periphery of the upper end of the effective area G1. According to the above embodiment, such an undesirable situation can be avoided.

[0077] In the above embodiment, the upper protrusion 9 is disposed at a position overlapping the gripping piece 2a in the vertical direction. Therefore, the upper planar portion Gc at the pressing part of the effective region G1 and the planar portion formed by the gripping piece 2a in the effective region G1 are arranged along the width direction at the upper end of the effective region G1. As a result, it is possible to more reliably suppress undue stress acting around the upper end of the effective region G1.

[0078] In the above embodiment, the intermediate protrusion 7 is disposed at a position that does not overlap with the upper protrusion 9 and the lower protrusion 10 in the vertical direction. Therefore, the curved portion Gw of the central portion of the effective region G1 in the vertical direction does not interfere with either the upper planar portion Gc or the lower planar portion Gd of the effective region G1. As a result, it is possible to suppress undue stresses acting on the periphery of both ends and the central portion of the effective region G1 in the vertical direction.

[0079] In the above embodiment, a curved portion Gwt is also formed at the central portion in the vertical direction of the unwanted region G2, thus concentrating the pressing force of the pressing member 6 on the central portion in the vertical direction of the unwanted region G2. Consequently, with the action of this concentrated pressing force, a larger bending stress can be applied to the central portion in the vertical direction of the scribe line forming region Gs. As a result, it is possible to more appropriately generate a crack at the central portion in the vertical direction of the scribe line S and allow the crack to extend in both the vertical and horizontal directions.

[0080] The above describes the method for manufacturing plate glass, the apparatus for manufacturing plate glass, and the plate glass according to embodiments of the present invention. However, the present invention is not limited thereto, and various modifications can be made without departing from its spirit.

[0081] In the above embodiment, the second region G2 is set as an unwanted region with the ear Ge, but the second region G2 can also be an unwanted region without the ear or become an effective region of the product (an effective region with the same plate thickness as the first region G1).

[0082] In the above embodiment, the back support member 3 and the pressing member 4 are used to forcibly form the curved portion Gws in the scribing forming region Gs. However, it is also possible to forcibly form the curved portion Gws in the scribing forming region Gs simply by contacting the back side Gb of the first region G1 with the back support member 3, without using the pressing member 4. In this case, at the initial stage of the breaking process, it is set to a state in which a force is applied to the second region G2 toward the back side Gy and the curved portion Gws is forcibly formed in the scribing forming region Gs. In this state, a further force can be applied to the second region G2 toward the back side Gy.

[0083] In the above embodiment, the intermediate protrusion 7 is provided at the center of the opposing portion 3x of the back support member 3 in the vertical direction. However, for the intermediate protrusion 7, as long as it is at the center of the opposing portion 3x of the back support member 3 in the vertical direction, it can also be provided at a position offset upward or downward from the center in the vertical direction. Similarly, the curved portion Gws of the scribe line forming region Gs is not limited to being formed at the center in the vertical direction; as long as it is at the center in the vertical direction, it can also be formed at a position offset upward or downward from the center in the vertical direction (the same applies to other curved portions Gw, Gws, Gwt, and Gwu).

[0084] In the above embodiment, the case where the entire area of ​​the second region G2 is bent into the shape specified above is taken as an example. However, as long as the scribing line forming area Gs is bent into the shape specified above, the periphery of the outer end in the width direction of the second region G2 may not be bent into the shape specified above. In addition, the periphery of the gripping part of the effective region G1 held by the gripping piece 2a may not be bent into the shape specified above.

[0085] In the above embodiments, the pressing member 6 and the adsorption mechanism 5 apply a pressing force to the second region G2 toward the back side Gy. However, the pressing member 6 may not be used, and instead, the adsorption mechanism 5 may apply a pulling force to the second region G2 toward the back side Gy. Alternatively, while the pressing member 6 and the adsorption mechanism 5 apply a pressing force to the second region G2 toward the back side Gy, a member that pulls the second region toward the back side Gy may be used instead of the pressing member. Alternatively, while the upper and lower ends of the second region G2 are held by a holding member such as a holding piece, the holding member may be moved toward the back side G, thereby applying a force to the second region G2 toward the back side Gy. It should be noted that in the above embodiments, the shape of the pressing member 6 is not limited to a plate with a flat portion 6a; it may be a prism with a flat portion, or a column or rod without a flat portion.

[0086] In the above embodiment, the upper end of the first region G1 is held by the holding piece 2a of the holding mechanism 2, but it is also possible to use other holding members such as suction cups to hold the upper end of the first region G1 instead.

[0087] Explanation of reference numerals in the attached figures

[0088] A manufacturing apparatus (breaking device) for a single sheet of glass.

[0089] 2 Controlling Institutions

[0090] 2a control sheet

[0091] 3. Back Support Components

[0092] 4 Pressing components

[0093] 5. Adsorption mechanism

[0094] 5b Adsorption Pad

[0095] 6 Press-in components

[0096] 7. Middle convex part

[0097] 9. Upper convex part

[0098] 10 Lower convex part

[0099] D Crack Origin

[0100] G-plate glass

[0101] G1 First Zone (Valid Area)

[0102] Ga surface of the first region

[0103] The back of the first region of Gb

[0104] G2 Second Region (No region required)

[0105] Surface of the second region of Gx

[0106] The back of Gy's second area

[0107] The region where the Gs scribed lines are formed (the area where the scribed lines are formed)

[0108] Gws curved section (curved section of the area where the scribing line forms)

[0109] Gcs planar portion (the planar portion above the area where the scribed line forms)

[0110] Gds planar portion (the planar portion below the area where the scribing line forms)

[0111] S-shaped scribing lines.

Claims

1. A method for manufacturing a sheet glass, comprising a breaking step, wherein the breaking step is for a sheet glass in a longitudinal orientation in which a first region and a second region are arranged adjacent to each other in the width direction and have scribed lines formed on the surface side of the boundary of these regions, wherein, while the first region is supported from the back side by a back support member, a force toward the back side is applied to the second region, thereby breaking the sheet glass along the scribed lines and cutting out the second region. The method for manufacturing the glass plate is characterized by the following: In the breaking process, by bringing the first region into contact with the back support member, a curved portion with a convex surface along the vertical direction is formed in the area where the scribed line is formed.

2. The method for manufacturing plate glass according to claim 1, wherein, The back support member has a central convex portion for forming a curved portion along the vertical direction at the middle of the vertical direction of the area where the scribed line is formed.

3. The method for manufacturing plate glass according to claim 2, wherein, The central protrusion bends in such a way that its protruding length gradually shortens from the center in the vertical direction toward both ends.

4. The method for manufacturing plate glass according to claim 2 or 3, wherein, The intermediate protrusion is disposed at a position that does not overlap with the retaining member holding the upper end of the first region in the vertical direction.

5. The method for manufacturing plate glass according to any one of claims 1 to 3, wherein, In the breaking process, the pressing member disposed on the surface side of the first region presses the first region toward the back support member.

6. The method for manufacturing plate glass according to claim 5, wherein, The pressing member has an upper protrusion for forming a planar portion at the upper end of the area where the scribed line is formed.

7. The method for manufacturing plate glass according to claim 6, wherein, The upper protrusion is disposed at a position that overlaps with the retaining member holding the upper end of the first region in the vertical direction.

8. The method for manufacturing plate glass according to claim 6 or 7, wherein, The back support member has a central convex portion for forming a curved portion along the vertical direction at the middle of the vertical direction of the area where the scribed line is formed. The upper protrusion is positioned at a location that does not overlap with the middle protrusion in the vertical direction.

9. The method for manufacturing plate glass according to claim 6 or 7, wherein, The pressing member has a lower convex portion for forming a planar portion at the lower end of the area where the scribed line is formed.

10. The method for manufacturing plate glass according to claim 9, wherein, The back support member has a central convex portion for forming a curved portion along the vertical direction at the middle of the vertical direction of the area where the scribed line is formed, which has a surface side convexity. The lower protrusion is positioned at a location that does not overlap with the middle protrusion in the vertical direction.

11. An apparatus for manufacturing sheet glass, comprising a breaking device configured to, for a sheet glass in a longitudinal orientation in which first and second regions are arranged adjacent to each other in the width direction and have scribed lines formed on the surface side of the boundary of these regions, while the first region is supported from the back side by a back support member, apply a force toward the back side to the second region, thereby breaking the sheet glass along the scribed lines and cutting out the second region. The apparatus for manufacturing the plate glass is characterized in that, The breaking device is configured to form a curved portion along the vertical direction with a surface side convexity in the area where the scribed line is formed by contacting the first region with the back support member.

12. A type of plate glass, which is a rectangular plate glass having two first sides extending along a first direction and two second sides extending along a direction different from the first direction. The glass pane is characterized in that... It has multiple stripes extending along the first direction on the surface and / or back side. A crack origin is provided for each of the first edges within a range of more than 25% and less than 75% of the total length of the first edge from one end toward the other. The crack origin is the starting point of crack propagation at the time of fracture. The face corresponding to the first edge is the cut-off end face. The origin of the crack is formed on the cut end face, and not on the surface or the back side.

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