CN117500764A - Method for producing plate glass, device for producing plate glass, and plate glass - Google Patents

Abstract

A method for manufacturing a sheet glass, comprising a breaking step of breaking a sheet glass (G) in a vertical position along a scribe line (S), wherein the first region (G1) and the second region (G2) are arranged adjacently in the width direction of the sheet glass (G), the scribe line (S) is formed on the boundary portion between the first region (G1) and the second region (G2) and on the sides of the surfaces (G1 a, G2 a) of the sheet glass (G), and in the breaking step, the first region (G1) is supported by a back support member (3) from the back surface (G1 b) side of the sheet glass and the second region (G2) is held by an adsorption mechanism (6) from the back surface (G2 b) side in a state in which a force directed to the back surface (G2 b) side acts on the second region (G2), thereby cutting the second region (G2), and a crack is stretched with the end of the scribe line (S) as a starting point. This can improve the quality of the breakage.

Description

Method for producing plate glass, device for producing plate glass, and plate glass

Technical Field

The present invention relates to a method for producing plate glass, an apparatus for producing plate glass, and an improvement of plate glass.

Background

As is well known, a sheet glass is used as a substrate or a cover in a display (e.g., a liquid crystal display, a plasma display, an organic EL display, etc.) and organic EL illumination. In manufacturing such a sheet glass, a step of sequentially cutting out a sheet glass of a predetermined length from a glass ribbon, a step of removing unnecessary regions along the edges of the sheet glass, and the like are performed. In these steps, after the glass ribbon and the sheet glass form the scribe line, they are broken along the scribe line.

As a specific example of a method for obtaining a sheet glass by breaking, a method disclosed in patent document 1 is given. In the method disclosed in this document, a scribe line is formed on the surface side of the sheet glass at the boundary portion between the first region and the second region which are adjacently arranged in the width direction of the sheet glass. The second region is pressed into the rear surface side by the rolling elements while the first region is being supported from the rear surface side by the rear surface support member. Thereby, bending stress is applied to the sheet glass and broken along the scribe line, cutting the second region. The breakage at this time is performed by supporting the sheet glass in a vertical posture.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2017-226549

Disclosure of Invention

Problems to be solved by the invention

When bending stress is applied to the sheet glass by the method described in patent document 1, uneven bending stress is applied to the scribe line. In the sheet glass, warpage inevitably occurs in the shape of the longitudinal section, and the shape and size of the warpage vary for each sheet glass. This warpage becomes particularly remarkable when the thickness of the sheet glass is 500 μm or less. When such a sheet glass is broken by the method described in patent document 1, the position of the starting point of a crack extending at the time of breaking is changed due to the change in the shape of the warp of the sheet glass, and the crack may extend from the middle portion of the scribe line. In this case, there are problems such as misalignment of the breaking position, breakage of the plate glass, occurrence of breakage (improper breakage of the broken end face), or excessive occurrence of glass frit, and deterioration of the broken quality.

The invention aims to improve the breaking quality of plate glass.

Means for solving the problems

In order to solve the above-described problems, the present invention provides a method for producing a sheet glass, comprising a breaking step of breaking a sheet glass in a vertical posture along a scribe line, wherein a first region and a second region are arranged adjacent to each other in a width direction of the sheet glass, the scribe line is formed on a boundary portion between the first region and the second region and on a front surface side of the sheet glass, and in the breaking step, a force is applied to the second region toward the rear surface side while the first region is supported by a rear surface support member from the rear surface side of the sheet glass and the second region is sucked and held from the rear surface side by a suction mechanism, thereby cutting the second region, and a crack is stretched with an end portion of the scribe line as a starting point. By extending the crack starting from the crack at the end of the score line, breakage, chipping, excessive glass frit generation, and the like of the sheet glass can be suppressed, and the quality of breakage can be improved.

In the above configuration, it is preferable that the suction means includes a plurality of suction members arranged along the scribe line, and in the breaking step, the suction members suction and hold the second region from the back surface side so that a height position of the second region as the starting point protrudes toward the front surface side. In the breaking step of the present invention, since a large bending stress acts on the end portion of the scribe line protruding toward the front surface side of the sheet glass, the crack reliably extends from the end portion of the scribe line, and the quality of breaking can be reliably improved.

In the above configuration, it is preferable that the glass sheet is held at an upper end portion by a holding mechanism, the scribe line extends in a vertical direction, and suction is started sequentially from the suction member located on an upper side among the plurality of suction members. When a plate glass having warpage is simultaneously suctioned by a plurality of suction members, the plate glass is suctioned and held in a state including warpage, and the vertical cross-sectional shape of the suctioned and held plate glass is liable to deviate. On the other hand, when suction is started in order from the suction member located on the upper side, warpage is corrected during suction, and the sectional shape of the suction-held sheet glass is stabilized. Therefore, the quality of the breakage can be improved more reliably.

In the above-described configuration, it is preferable that the suction member on the end portion side protruding toward the front surface side of the plurality of suction members has a suction pressure lower than that of the other suction members. Here, the adsorption pressure is a value obtained by subtracting the pressure inside the adsorption member from the atmospheric pressure. The suction member (for example, suction pad) is flexible, and therefore deforms so as to be drawn in the direction of the suction member when the sheet glass is sucked. The suction member having a low suction pressure is pulled into the suction member side by a smaller amount than the suction member having a high suction pressure, and the sheet glass protrudes toward the front surface side. Thus, the end portion of the scribe line is projected toward the surface side by making the suction pressure of the suction member located on the upper side or the lower side low.

In the above-described configuration, in the breaking step, it is preferable that the first region is brought into contact with the back surface support member so that a height position of the first region as the starting point protrudes toward the front surface side. According to this structure, the crack is propagated starting from the crack at the end of the score line, so that breakage, chipping, excessive generation of glass frit, and the like of the sheet glass can be suppressed, and the quality of breakage can be improved.

The present invention provides a sheet glass manufacturing apparatus including a breaking device for breaking a sheet glass in a vertical posture along a scribe line, wherein a first region and a second region are arranged adjacent to each other in a width direction of the sheet glass, the scribe line is formed on a boundary portion between the first region and the second region and on a surface side of the sheet glass, the breaking device including: a back support member that supports the first region from a back side contact of the sheet glass; an adsorption mechanism that adsorbs and holds the second region from the back surface side; and a pressing member that applies a force to the second region toward the back surface side, wherein the breaking device is configured to propagate a crack starting from an end of the scribe line. According to this structure, the same operational effects as those of the above-described manufacturing method having substantially the same structure as the manufacturing apparatus can be obtained.

The sheet glass of the present invention has two first end faces extending in the drawing direction and two second end faces extending in the width direction intersecting the drawing direction, and has a rectangular shape, and is characterized in that at least one of the first end faces is a cut surface formed by breaking, and has a score line, and the breaking start point is located at an end of the score line.

The closer the fracture surface formed by the fracture is to the start point of the fracture, the narrower the rib spacing is. The rib-like lines are arc-like wave patterns formed perpendicularly to the direction of propagation of the crack, and when a tensile stress is applied to a region where a plurality of rib-like lines exist, the crack may progress from the rib-like lines as a starting point, and the sheet glass may be broken.

When manufacturing a display, an organic EL-illuminated substrate, and a cover using a sheet glass, the sheet glass may be transported in a vertical posture. Specifically, the upper portion of the vertical plate glass is held by a chuck mechanism of the conveying device, and the plate glass is conveyed in a suspended state. In such a case of carrying, the sheet glass is liable to swing like a vibrator due to the influence of air resistance, inertial force, and the like. When the swing becomes large, a tensile stress is applied to a portion bent by the swing, and the sheet glass may be broken.

The region of the vertical posture conveyed sheet glass having the same height as the upper end portion of the scribe line mark is held by the chuck mechanism, and therefore the sheet glass is hard to bend even if it swings. In addition, since the region of the sheet glass conveyed in the vertical posture having the same height as the lower end portion of the score line is not held and is free, the sheet glass is hard to bend even if it swings. Therefore, since the starting point of the break is located at the end of the scribe line, the region including the starting point of the break is hard to bend, and it is difficult to apply tensile stress. Thus, the sheet glass having such a structure is hardly broken when being conveyed in the vertical posture.

Effects of the invention

According to the present invention, the crack is extended with the end of the scribe line as the starting point, and the quality of the fracture can be improved.

Drawings

Fig. 1 is a perspective view showing a breaking device included in a device for manufacturing a sheet glass according to a first embodiment of the present invention.

Fig. 2 is a B-B cross-sectional view of fig. 1.

Fig. 3 is a perspective view showing the operation of the breaking device included in the apparatus for manufacturing a sheet glass according to the first embodiment of the present invention.

Fig. 4 is a C-C cross-sectional view of fig. 3.

Fig. 5 (a), (b), and (c) are plan views showing the sequence of breaking a sheet glass using a breaking device included in the apparatus for manufacturing a sheet glass according to the first embodiment of the present invention.

Fig. 6 is a plan view showing a breaking device included in the apparatus for manufacturing a sheet glass according to the first embodiment of the present invention.

Fig. 7 is a perspective view showing the operation of a breaking device included in the apparatus for manufacturing a sheet glass according to the second embodiment of the present invention.

Fig. 8 is a D-D cross-sectional view of fig. 7.

Fig. 9 (a), (b), and (c) are plan views showing the sequence of breaking a sheet glass using a breaking device included in the apparatus for manufacturing a sheet glass according to the second embodiment of the present invention.

Fig. 10 is a perspective view showing the operation of a breaking device included in the apparatus for manufacturing a sheet glass according to the third embodiment of the present invention.

Fig. 11 is an E-E sectional view of fig. 10.

Fig. 12 is an E-E cross-sectional view of fig. 10, and only the sheet glass is shown.

Fig. 13 (a), (b), and (c) are plan views showing the sequence of breaking a sheet glass using a breaking device included in the apparatus for manufacturing a sheet glass according to the third embodiment of the present invention.

Fig. 14 is a perspective view showing the operation of a breaking device included in the apparatus for manufacturing a sheet glass according to the fourth embodiment of the present invention.

Fig. 15 is a cross-sectional view of F-F of fig. 14.

Fig. 16 is a F-F cross-sectional view of fig. 14, and only the sheet glass is shown.

Fig. 17 (a), (b), and (c) are plan views showing the sequence of breaking a sheet glass using a breaking device included in the apparatus for manufacturing a sheet glass according to the fourth embodiment of the present invention.

Fig. 18 is a perspective view showing a sheet glass according to an embodiment of the present invention.

Fig. 19 is a perspective view showing an end face of a sheet glass according to an embodiment of the present invention.

Fig. 20 is a perspective view showing an end face of a sheet glass according to an embodiment of the present invention.

Detailed Description

Hereinafter, a method for producing a sheet glass, an apparatus for producing a sheet glass, and an embodiment of a sheet glass according to the present invention will be described with reference to the drawings.

(first embodiment)

Fig. 1 shows a breaking device 1 and a sheet glass G included in the apparatus for manufacturing a sheet glass according to the present embodiment. The plate glass G has a first region G1 and a second region G2 adjacently arranged in the width direction. The first region G1 is a region to be a product of the sheet glass G, and the thickness of the sheet glass is uniform throughout the entire region. The second region G2 is a region cut out from the plate glass G and discarded, and has an ear Ge thicker in plate thickness than the first region G1 at a front end portion in the width direction (a front end portion on the left side in the drawing). At the boundary between the first region G1 and the second region G2, the scribe line S is formed on the surfaces G1a, G2a side. In the illustration, the scribe line S does not reach the upper end face and the lower end face of the sheet glass G. The scribe line S may reach the upper end surface and the lower end surface of the sheet glass G. In the following description, for convenience, the first region G1 is referred to as an effective region, and the second region G2 is referred to as an unnecessary region.

The sheet glass G is suspended and supported in a vertical posture so that the scribe line S faces in the up-down direction. The thickness of the plate glass G (plate thickness of the region other than the ear portion Ge) is, for example, 50 to 2000. Mu.m. The sheet glass G is rich in flexibility and the warp in the longitudinal section is remarkable, and the effect of the present invention is increased, so that the thickness of the sheet glass G is preferably 50 to 500 μm, more preferably 50 to 400 μm. The specific shape of the warpage is a shape in which a scribe line S in the surfaces G1a, G2a of the sheet glass G and an arbitrary virtual straight line parallel to the scribe line S are curved. The shape of the warpage varies depending on the manufacturing apparatus, the manufacturing conditions, and the passage of time.

The sheet glass G can be obtained, for example, in the following procedure.

(1) The glass ribbon is formed by overflow downdraw.

(2) The formed glass ribbon is annealed.

(3) The annealed glass ribbon is broken and cut in the width direction to cut out the sheet glass G from the glass ribbon.

When the sheet glass G is obtained from the glass ribbon formed by the overflow downdraw method as described above, the front faces G1a, G2a and the rear faces G1b, G2b are all forged faces, and the surface properties are excellent. In this case, stripe patterns in the form of stripes extending in the up-down direction (draw-plate direction) are formed on the front faces G1a, G2a and the rear faces G1b, G2b of the plate glass G, which are not shown. The upper end surface and the lower end surface of the plate glass G are cut surfaces formed by breaking.

The dimensions of the plate glass G after breaking are, for example, 1800mm×2000mm or more, preferably 2200mm×2500mm or more, more preferably 2600mm×3000mm or more, and still more preferably 2900mm×3300mm or more.

Examples of the composition of the sheet glass G include alkali-free glass, borosilicate glass, soda glass (soda lime glass), high silica glass, and other oxide-based glass containing silica as a main component. The plate glass G may be glass for chemical strengthening, and in this case, aluminosilicate glass can be used.

The breaking device 1 breaks the sheet glass G along the scribe line S in order to remove the unnecessary region G2. Specifically, the breaking device 1 includes: a holding mechanism 2 for holding an upper end portion of the effective region G1; a back surface support member 3 disposed on the back surface G1b side of the active region G1; a pressing member 4 disposed opposite to the back surface support member 3 on the front surface G1a side of the effective area G1; a suction mechanism 6 disposed on the back surface G2b side of the unnecessary area G2; and a press-fitting member 5 disposed opposite to the suction mechanism 6 on the surface G2a side of the unnecessary area G2.

The holding mechanism 2 includes a pair of holding pieces 21 and a driving portion 22 for moving the pair of holding pieces 21 toward and away from each other. The structure of the driving section 22 is not limited to the example of the drawing. The pair of holding pieces 21 hold the upper end portion of the effective area G1 in a closed state by approaching each other, and release the holding of the upper end portion of the effective area G1 in an open state by moving away from each other.

The holding mechanism 2 is slidably held by a rail (not shown) extending in the width direction above the sheet glass G, and functions to carry the sheet glass G in and out of the breaking position. When the sheet glass G is broken at the breaking position, the holding mechanism 2 is stopped while holding the upper end of the holding effective area G1. In this case, the lower end portion of the plate glass G is not held but is free. The holding mechanism 2 holds a plurality of portions (two portions (one portion is not shown in the figure) in the width direction of the upper end portion of the effective region G1 in this embodiment).

The back support member 3 contacts and supports the effective region G1 from the back Gib side at the time of breaking of the sheet glass G. The rear surface support member 3 moves closer to and away from the rear surface Gib of the effective area G1 by operation of a fluid pressure cylinder such as an air cylinder, a driving mechanism (not shown) such as a ball screw mechanism or a robot arm. The back support member 3 is a columnar body or a plate-like body long in the up-down direction. The back surface support member 3 is disposed along the scribe line S, and the separation distance between the back surface support member 3 and the scribe line S in the width direction (separation distance when the back surface support member 3 contacts the effective region G1) is preferably 10 to 30mm, more preferably 10 to 20mm. In the illustrated example, the back support member 3 extends from the upper end face and the lower end face of the effective region G1, but may not extend from the upper end face and the lower end face of the effective region G1.

The pressing member 4 presses the effective region G1 against the back surface support member 3 when the sheet glass G breaks. The pressing member 4 moves closer to and away from the surface G1a of the effective area G1 by operation of a fluid pressure cylinder such as an air cylinder, a driving mechanism (not shown) such as a ball screw mechanism or a robot arm. In this embodiment, the pressing member 4 is a columnar body or a plate-like body that is long in the up-down direction. In the illustrated example, the pressing member 4 extends from the upper end face and the lower end face of the effective area G1, but may not extend from the upper end face and the lower end face of the effective area G1.

Fig. 2 is a cross-sectional view of the B-B position of fig. 1. The suction mechanism 6 includes a holding base 61 long in the vertical direction, and a plurality of suction members 62 attached to the holding base 61. The holding base 61 is rotated and moved (for example, rotated and moved in the direction of arrow a shown in fig. 1) by the operation of a driving mechanism (not shown) such as a robot arm. The suction member 62 is a suction pad for sucking and holding the back surface G2b of the unnecessary area G2 by negative pressure, and is formed of an elastic member such as rubber or resin. The adsorbing members 62 are attached to the holding base 61 in a vertically aligned manner. In the present embodiment, three adsorbing members 62 are attached, but this is not a limitation. Two or more than four adsorbent members 62 may also be used.

The press-fitting member 5 has a flat surface portion 51 that contacts the surface G2a of the unnecessary region G2, and in this embodiment, has a plate shape that is long in the up-down direction. The press-fitting member 5 is rotated and moved (for example, rotated in the direction of arrow a shown in fig. 1) by an operation of a driving mechanism (not shown) such as a robot arm, thereby applying a press-fitting force to the unnecessary area G2 toward the back surface G2 b. In the illustrated example, the press-fit member 5 extends from the upper end surface and the lower end surface of the unnecessary region G2, but may not extend from the upper end surface and the lower end surface of the unnecessary region G2.

Next, a method for manufacturing a sheet glass using the manufacturing apparatus of the first embodiment will be described.

First, in the step upstream of the position shown in fig. 1, the scribing line S is formed on the surface G1a, G2a side of the sheet glass G by pressing by a cutter wheel, irradiation of laser light, or the like in a state where the sheet glass G is suspended and supported by the holding mechanism 2. Specifically, a scribe line S is formed at the boundary between the effective region G1 and the unnecessary region G2 of the sheet glass G. Next, the sheet glass G on which the scribe line S is formed is conveyed in the width direction while being suspended and supported by the holding mechanism 2, so that the sheet glass G reaches the breaking position shown in fig. 1. At this time, the pressing member 4 and the back surface support member 3 are separated from the front surface G1a and the back surface G1b of the effective area G1, respectively, and the pressing member 5 and the suction mechanism 6 are also separated from the front surface G2a and the back surface G2b of the unnecessary area G2, respectively. In this state, warpage occurs in the shape of the longitudinal section in the sheet glass G.

After that, the back support member 3 moves toward the effective area G1, and the pressing member 4 also moves toward the effective area G1. As shown in fig. 3, at the time when the movement of the back support member 3 and the pressing member 4 is completed, the effective area G1 is supported by the back support member 3 in a state sandwiched by the back support member 3 and the pressing member 4. Further, the suction mechanism 6 moves toward the unnecessary area G2, and the suction member 62 contacts the back surface G2b of the unnecessary area G2.

As shown in fig. 4, when the adsorbing member 62 comes into contact with the unnecessary region G2, the adsorbing member 621 located at the uppermost portion starts adsorbing. After the lapse of a predetermined time, the adsorbing member 622 located at the second from the top starts adsorbing. After a predetermined time has elapsed, the adsorbing member 623 located the third from the top starts adsorbing. Here, when the plate glass G having warpage is simultaneously suctioned by the plurality of suction members 621 to 623, warpage is included in the longitudinal sectional shape of the suctioned plate glass G, and the longitudinal sectional shape of the suctioned and held plate glass G is liable to deviate. On the other hand, when the suction members 621 to 623 are sequentially sucked from above as described above, warpage is corrected during suction, and the cross-sectional shape of the suction-held sheet glass G is stabilized. In the present embodiment, three adsorbing members 62 are used, but even in the case where two or more adsorbing members 62 are used, the same effect can be obtained by sequentially adsorbing from the adsorbing member 62 located on the upper side.

The suction pressure when the suction member 62 sucks the plate glass G is set to be lower as the suction member 62 is located at the upper side in the longitudinal direction of the plate glass G. Here, the adsorption pressure is a value obtained by subtracting the pressure inside the adsorption member 62 from the atmospheric pressure. Thus, the region having the same height position as the upper end portion of the scribe line S in the unnecessary region G2 (hereinafter, also referred to as "upper end region G2U of the unnecessary region G2") protrudes toward the surface G2a side than the region having the same height position as the middle portion or the lower end portion of the scribe line S. The protruding amount D2U of the upper end region G2U of the unnecessary region G2 is, for example, 10 to 300mm, preferably 30 to 100mm. This makes it possible to reliably start the breakage of the upper end portion of the scribe line S and to reliably prevent breakage of the sheet glass G during the breakage.

Fig. 5 (a), (b), and (c) are plan views of the breaking device showing the sequence of breaking the sheet glass G after that. Fig. 5 (a) shows an initial stage of the breaking step, in which the unnecessary region G2 has a shape in which the upper end region G2U protrudes toward the surface G2 a. From this state, the press-fit member 5 is moved, and as shown in fig. 5 (a), the press-fit member 5 is brought into contact with the unnecessary region G2. When the movement of the press-in member 5 is continued, the unnecessary area G2 is bent toward the back surface G2b with the back surface support member 3 as a fulcrum, as shown in fig. 5 (b). At this time, the press-fit member 5 rotates with the movement of the press-fit member 5. Accordingly, the suction mechanism 6 rotates while moving in the direction of arrow a. The suction mechanism 6 does not substantially apply a pulling-in force to the unnecessary area G2 toward the back surface G2 b. In this process, bending deformation in the width direction is generated around the scribe line S, and thus bending stress acts on the scribe line S. Further, since the upper end region G2U of the unnecessary region G2 protrudes toward the surface G2a side, the maximum bending stress acts on the upper end portion of the scribe line S. Then, with further movement of the press-fit member 5, at a time when the bending stress acting on the upper end portion of the scribe line S is sufficiently large, the crack extends in the thickness direction and the direction of the scribe line S with the upper end portion of the scribe line S as a starting point. In this way, the crack propagates in the entire scribe line S, and the sheet glass G is broken along the scribe line S as shown in fig. 5 (c). After the unnecessary region G2 is cut out by breaking the sheet glass G, the unnecessary region G2 is conveyed to the retracted position in a state of being gripped by the suction mechanism 6, and thereafter, the gripping by the suction mechanism 6 is released and falls and is recovered.

In the breaking device 1 and the breaking step described above, the unnecessary region G2 at one end in the width direction of the sheet glass G is described as an object, but the unnecessary region G2 is generally formed at each of the two ends in the width direction of the sheet glass G. The sheet glass G is broken to remove the unnecessary region G2, and the following structure is employed. That is, as shown in fig. 6, the widthwise central side region of the plate glass G is an effective region G1 and the widthwise both sides thereof are unnecessary regions G2. Scribe lines S are formed at both boundary portions between the effective region G1 and the unnecessary region G2, respectively. The breaking of the sheet glass G along the two scribe lines S is performed by the breaking device 1 disposed in correspondence with each unnecessary region G2. Each of the breaking devices 1 includes a pressing member 4 and a back surface supporting member 3 disposed on the front surface G1a side and the back surface G1b side of the effective region G1, respectively, and a pressing member 5 and a suction mechanism 6 disposed on the front surface G2a side and the back surface G2b side of the unnecessary region G2, respectively. The pressing member 5 and the suction mechanism 6 are configured to rotate and move in the direction of arrow a at both positions. The detailed construction of the two breaking devices 1 is the same as the breaking device 1 already described. In this case, the breaking by the two breaking devices 1 may be performed simultaneously, or the breaking by the other breaking device 1 may be performed after the breaking by the one breaking device 1 is completed. Alternatively, the sheet glass G may be moved in the width direction after the one unnecessary region G2 is broken and removed by the one breaking device 1 and the other unnecessary region G2 is broken and removed by the other breaking device 1 by disposing the one breaking device 1 at a distance longer than the length in the width direction of the sheet glass G. Alternatively, the breaking device 1 may be provided as one, and after the unnecessary region G2 of one is broken and removed by the breaking device 1, the sheet glass G may be rotated 180 degrees in a plan view, and then the unnecessary region G2 of the other may be broken and removed by the breaking device 1.

(second embodiment)

Hereinafter, a method for manufacturing a sheet glass according to a second embodiment of the present invention will be described. In the description of the second embodiment, the same reference numerals are given to the structures substantially identical to those described in the first embodiment, and overlapping descriptions are omitted, so that only the structures different from those of the first embodiment will be described.

The manufacturing apparatus of the second embodiment has the same configuration as the manufacturing apparatus of the first embodiment, but the suction pressure when the suction member 62 sucks the plate glass G is set so as to be lower as the suction member 62 is located on the lower side in the longitudinal direction of the plate glass G. In this way, in the second embodiment, the crack is stretched with the lower end of the scribe line S as the starting point.

As shown in fig. 7 and 8, the region having the same height position as the lower end portion of the scribe line S (hereinafter, also referred to as "lower end region G2L of the unnecessary region G2") in the unnecessary region G2 protrudes toward the surface G2a side than the region having the same height position as the middle portion or the upper end portion of the scribe line S. The protruding amount D2L of the lower end region G2L of the effective region G2 is preferably 10 to 300mm, more preferably 10 to 100mm.

Fig. 9 (a), (b), and (c) are plan views of the breaking device showing the sequence of breaking the sheet glass G after that. Fig. 9 (a) shows an initial stage of the breaking step, in which the unnecessary region G2 has a shape in which the lower end region G2L protrudes toward the surface G2 a. From this state, the press-in member 5 is moved, and the unnecessary area G2 is bent toward the back surface G2b with the back surface support member 3 as a fulcrum, as shown in fig. 9 (b). In this process, bending deformation in the width direction is generated around the scribe line S, and thus bending stress acts on the scribe line S. Further, since the lower end region G2L of the unnecessary region G2 protrudes toward the surface G2a side, the maximum bending stress acts on the lower end portion of the scribe line S. Then, with further movement of the press-fit member 5, at a time when the bending stress acting on the lower end portion of the scribe line S is sufficiently large, the crack extends in the thickness direction and the direction of the scribe line S with the lower end portion of the scribe line S as a starting point. In this way, the crack propagates in the entire scribe line S, and the sheet glass G is broken along the scribe line S as shown in fig. 9 (c).

(third embodiment)

A method for producing a sheet glass and an apparatus for producing a sheet glass according to a third embodiment of the present invention will be described below. In the description of the third embodiment, the same components as those described in the first and second embodiments are substantially the same as each other, and the same reference numerals are given thereto, so that redundant description is omitted, and only components different from those of the first and second embodiments are described.

Fig. 10 shows a breaking device 1 included in a device for manufacturing sheet glass according to a third embodiment. The breaking device 1 according to the third embodiment is different from the breaking device 1 according to the first embodiment in the configuration of the back surface support member 3 and the pressing member 4 and in the setting of the suction pressure of the suction member 62.

Fig. 11 is a sectional view taken along line E-E of fig. 10. The pressing member 4 has a lower protruding portion 43 at a lower end portion of the opposing portion 42 opposing the surface G1a of the plate glass G (the effective region G1). Specifically, the pressing member 4 has a columnar or plate-like support base 41. A lower convex portion 43 having a curved surface is fixedly provided on the surface portion of the support base 41. The surface of the lower convex portion 43 is smoothly curved so that the length protruding from the support base 41 becomes gradually shorter from the lower side to the upper side. The surface of the lower protruding portion 43 may be an inclined surface.

The lower protruding portion 43 is disposed at a position not overlapping the grip piece 21 gripping the upper end portion of the effective area G1 in the vertical direction. That is, the upper end 43U of the lower protruding portion 43 is located below the lower end 21L of the grip piece 21. The lower convex portion 43 is softer than the plate glass G and the support base 41 and is excellent in elasticity and cushioning properties, and is formed of, for example, a porous resin or a foamed resin typified by a plastic corrugated paper or a PP foam board (registered trademark), FC nylon (registered trademark), or the like. A single cover sheet 44 for covering the support base 41 and the lower protruding portion 43 is attached to the surface thereof. The cover sheet 44 is softer than the lower protruding portion 43, and is formed of, for example, a porous resin or a foamed resin typified by a sponge or a low-resilience sponge.

The back surface support member 3 has an upper convex portion 33 at an upper end portion of the opposing portion 32 opposing the back surface G1b of the plate glass G (effective region G1). More specifically, the back support member 3 has a columnar or plate-like support base 31. An upper convex portion 33 is fixedly provided on the surface of the support substrate 31. The surface of the upper convex portion 33 is smoothly curved so that the length protruding from the support base 31 becomes gradually shorter from the upper side to the lower side. The surface portion of the support substrate 31 may be a curved surface.

The upper protruding portion 33 is disposed at a position overlapping the grip piece 21 gripping the upper end portion of the effective area G1 in the vertical direction. That is, the upper end 33U of the upper protruding portion 33 is located above the upper end 21U of the grip piece 21, and the lower end 33L of the upper protruding portion 33 is located below the lower end 21L of the grip piece 21. The upper protruding portion 33 may be disposed at a position overlapping only a part of the grip piece 21 in the vertical direction. In this embodiment, the upper end 33U of the upper protruding portion 33 protrudes from the upper end of the plate glass G, but may not protrude. The upper convex portion 33 is softer than the plate glass G and the support base 31 and is excellent in elasticity and cushioning properties, and is formed of, for example, a porous resin or a foamed resin typified by a plastic corrugated paper or a PP foam board (registered trademark), FC nylon (registered trademark), or the like. A single cover sheet 34 for covering the support base 31 and the upper protruding portion 33 is attached to the surface thereof. The cover sheet 34 is softer than the upper convex portion 33, and is formed of, for example, a porous resin or a foamed resin typified by a sponge or a low-resilience sponge.

Next, a method for manufacturing a sheet glass using the manufacturing apparatus of the third embodiment will be described.

As in the first embodiment, after the sheet glass G on which the score line S is formed is brought to the breaking position, the back surface support member 3 is moved toward the effective area G1, and the pressing member 4 is also moved toward the effective area G1. As shown in fig. 11, at the time when the movement of the back support member 3 and the pressing member 4 is completed, the effective area G1 is supported by the back support member 3 in a state sandwiched by the back support member 3 and the pressing member 4. As a result, as shown in fig. 12, in the effective region G1, a region having the same height position as the upper end portion of the scribe line S (hereinafter, also referred to as "upper end region G1U of the effective region G1") protrudes toward the surface G1a side than a region having the same height position as the middle portion or the lower end portion of the scribe line S. The protruding amount D1U of the upper end region G1U of the effective region G1 is preferably 10 to 300mm, more preferably 10 to 100mm. Further, the suction mechanism 6 moves toward the unnecessary area G2, and the suction member 62 contacts the back surface G2b of the unnecessary area G2.

As shown in fig. 10, when the adsorbing member 62 contacts the unnecessary area G2, adsorption is performed sequentially from the adsorbing member 62 located on the upper side as in the first embodiment. The adsorption pressures of the plurality of adsorption members 62 are set equal. Therefore, the upper end region G2U of the unnecessary region G2 does not protrude, and the surface G2a of the unnecessary region G2 is substantially parallel to the vertical plane.

Fig. 13 (a), (b), and (c) are plan views of the breaking device showing the sequence of breaking the sheet glass G after that. Fig. 13 (a) shows an initial state of the breaking step, in which the effective region G1 has a shape in which the upper end region G1U protrudes toward the surface G1 a. From this state, the press-in member 5 is moved, and the unnecessary area G2 is bent toward the back surface G2b with the back surface support member 3 as a fulcrum, as shown in fig. 13 (b). In this process, bending deformation in the width direction is generated around the scribe line S, and thus bending stress acts on the scribe line S. Further, since the upper end region G1U of the effective region G1 protrudes toward the surface G1a, the maximum bending stress acts on the upper end portion of the scribe line S. Then, with further movement of the press-fit member 5, at a time when the bending stress acting on the upper end portion of the scribe line S is sufficiently large, the crack extends in the thickness direction and the direction of the scribe line S with the upper end portion of the scribe line S as a starting point. In this way, the crack propagates in the entire scribe line S, and the sheet glass G is broken along the scribe line S as shown in fig. 13 (c).

(fourth embodiment)

A method for producing a sheet glass and an apparatus for producing a sheet glass according to a fourth embodiment of the present invention will be described below. In the description of the fourth embodiment, the same reference numerals are given to the structures substantially identical to those described in the first, second, and third embodiments, and overlapping description is omitted, so that only the structures different from those of the first, second, and third embodiments will be described.

Fig. 14 shows a breaking device 1 included in a device for manufacturing sheet glass according to a fourth embodiment. The breaking device 1 of the fourth embodiment is different from the breaking device 1 of the third embodiment in the structure of the back surface support member 3 and the pressing member 4.

Fig. 15 is a cross-sectional view taken along line F-F of fig. 14. The back surface support member 3 has a lower convex portion 35 at a lower end portion of the opposing portion 32 opposing the back surface G1b of the plate glass G (effective region G1). More specifically, the back support member 3 has a columnar or plate-like support base 31. A lower convex portion 35 having a curved surface is fixedly provided on the surface portion of the support base 31. The lower protruding portion 35 has the same material and shape as the lower protruding portion 43 of the pressing member 4 in the third embodiment.

The pressing member 4 has an upper convex portion 45 at an upper end portion of the opposing portion 42 opposing the surface G1a of the plate glass G (the effective region G1). Specifically, the pressing member 4 has a columnar or plate-like support base 41. An upper convex portion 45 having a curved surface is fixedly provided on the surface portion of the support base 41. The upper convex portion 45 has the same material and shape as those of the upper convex portion 33 of the back surface support member 3 in the third embodiment.

Next, a method for manufacturing a sheet glass using the manufacturing apparatus of the fourth embodiment will be described.

As in the first embodiment, after the sheet glass G on which the score line S is formed is brought to the breaking position, the back surface support member 3 is moved toward the effective area G1, and the pressing member 4 is also moved toward the effective area G1. As shown in fig. 15, at the time when the movement of the back support member 3 and the pressing member 4 is completed, the effective area G1 is supported by the back support member 3 in a state sandwiched by the back support member 3 and the pressing member 4. As a result, as shown in fig. 16, in the effective region G1, a region having the same height position as the lower end portion of the scribe line S (hereinafter, also referred to as "lower end region G1L of the effective region G1") protrudes toward the surface G1a side than a region having the same height position as the middle portion or the upper end portion of the scribe line S. The protruding amount D1L of the lower end region G1L of the effective region G1 is preferably 10 to 300mm, more preferably 10 to 100mm. Further, the suction mechanism 6 moves toward the unnecessary area G2, and the suction member 62 contacts the back surface G2b of the unnecessary area G2.

As shown in fig. 14, when the adsorbing member 62 contacts the unnecessary area G2, adsorption is performed as in the third embodiment.

Fig. 17 (a), (b), and (c) are plan views of the breaking device showing the sequence of breaking the sheet glass G after that. Fig. 17 (a) shows an initial stage of the breaking process, in which the effective region G1 has a shape in which the lower end region G1L protrudes toward the surface G1 a. From this state, the press-in member 5 is moved, and the unnecessary area G2 is bent toward the back surface G2b with the back surface support member 3 as a fulcrum, as shown in fig. 17 (b). In this process, bending deformation in the width direction is generated around the scribe line S, and thus bending stress acts on the scribe line S. Further, since the lower end region G1L of the effective region G1 protrudes toward the surface G1a, the maximum bending stress acts on the upper end portion of the scribe line S. Then, with further movement of the press-fit member 5, at a time when the bending stress acting on the upper end portion of the scribe line S is sufficiently large, the crack extends in the thickness direction and the direction of the scribe line S with the lower end portion of the scribe line S as a starting point. In this way, the crack propagates in the entire scribe line S, and the sheet glass G is broken along the scribe line S as shown in fig. 17 (c).

According to the apparatus for manufacturing a sheet glass as described above, the end portion of the scribe line can be projected to the front side at the time of breaking the sheet glass. This makes it possible to extend the crack starting from the end of the scribe line, thereby improving the quality of the fracture. Further, since the suction is started in order from the suction member located at the upper side, warpage is corrected during suction, and the cross-sectional shape of the suction-held sheet glass can be stabilized.

The reason why the breaking quality can be improved by the present invention, more specifically, the reason why breakage, chipping, excessive generation of glass frit, etc. of the sheet glass can be suppressed is not clear. The inventors conducted a test for breaking 100 glass sheets by stretching a crack using the upper end of the score line as a starting point in the first embodiment. As a result, breakage and breakage of the sheet glass and excessive generation of glass frit were not observed. The dimensions of the sheet glass used in the test were 3500mm×3500mm, and the thickness thereof was 500 μm. For comparison, a test was performed in which the suction pressure was changed so that the center portion of the scribe line protruded to the front side, and the crack was extended from the center portion of the scribe line to break 100 glass sheets. As a result, breakage of 4 glass plates resulted in breakage of 13 glass plates and excessive glass frit resulted in 15 glass plates.

Here, the end of the scribing line S means a range of less than 25% of the length of the scribing line S from the front end of the scribing line S. The starting point of the crack is more preferably located on the front end side in the end of the scribe line S, in other words, in a range of less than 12.5% of the length of the scribe line S from the front end of the scribe line S.

Next, a sheet glass according to an embodiment of the present invention will be described.

As shown in fig. 18, the sheet glass G manufactured by the sheet glass manufacturing apparatus and the sheet glass manufacturing method using the sheet glass manufacturing apparatus according to the embodiment of the present invention has a rectangular shape having two first end faces G4 extending in the drawing direction Z and two second end faces G5 extending in the width direction intersecting the drawing direction Z.

The drawing direction Z of the sheet glass G can be observed as a stripe pattern of a stripe shape by, for example, adjusting the angle of the sheet glass G in a darkroom, and irradiating light from a light source (for example, a xenon lamp) and projecting the transmitted light toward the screen. Thus, even in the state of the plate glass G after the forming, the drawing direction Z at the time of forming can be determined.

At least one first end surface G4 is a cut surface formed by breaking, and has score lines S1 and rib-like patterns RM as shown in fig. 19 and 20. The rib RM is a circular arc-shaped wave pattern formed perpendicularly to the direction of travel of the crack, and shows the direction of extension of the fracture of the crack. Fig. 19 shows a sheet glass G broken by a crack that is a starting point of breaking and that progresses downward at the upper end of the score line S1. Fig. 20 shows a sheet glass G broken by a crack that is generated at the lower end of the score line S1 and serves as a starting point of breaking, and the breaking proceeds upward. The closer to the position of the start point of the crack extending at the time of breaking, the narrower the interval between the adjacent rib-like grains RM. When a tensile stress is applied to a region where a plurality of ribs RM are present, a crack may progress from the rib RM as a starting point, and the sheet glass G may be broken.

When manufacturing a display, an organic EL-illuminated substrate, and a cover using the sheet glass G, the sheet glass G may be conveyed in a vertical posture. Specifically, the upper portion of the vertical plate glass G is held by a chuck mechanism (not shown) of the conveying device, and the plate glass G is conveyed in a suspended state. In such a case of carrying, the plate glass G is liable to swing like a vibrator due to the influence of air resistance, inertial force, and the like. When the swing is large, a tensile stress is applied to a portion bent by the swing, and the sheet glass G may be broken.

Since the region of the sheet glass G conveyed in the vertical posture having the same height as the upper end portion of the scribe line S1 is held by the chuck mechanism, the sheet glass G is hard to bend even if it swings. In addition, since the region of the sheet glass G conveyed in the vertical posture having the same height as the lower end portion of the score line S1 is not held and is free, the sheet glass G is hard to bend even if it swings. Therefore, by the start point of the break being located at the end of the score line S1, the region including the start point of the break is hard to bend, and it is difficult to apply tensile stress. Thus, the effect is obtained that the sheet glass G is hardly broken when conveyed in the vertical posture.

The present invention is not limited to the configuration of the above embodiment, and is not limited to the above-described operational effects. The present invention can be variously modified within a range not departing from the gist of the present invention.

In the above embodiment, the upper end portion of the first region G1 is held by the holding piece 21 of the holding mechanism 2, but may be held by another holding member such as a suction cup instead of this.

In the above embodiment, the second region G2 is set as the unnecessary region having the ear Ge, but the second region G2 may be an unnecessary region having no ear Ge or may be an effective region (an effective region having the same plate thickness as the first region G1) to be a product.

In the above embodiment, the pressing force toward the rear surface G2b is applied to the second region G2 by the pressing member 5 and the suction mechanism 6, but the pulling force toward the rear surface G2b may be applied to the second region G2 by the suction mechanism 6 without using the pressing member 5. The pressing force toward the rear surface G2b is applied to the second region G2 by the pressing member 5 and the suction mechanism 6, but instead of the pressing member, a member that pulls the second region G2 toward the rear surface G2b by a pulling member may be used. Alternatively, the holding member may be moved toward the rear surface 2b side in a state where the upper end portion and the lower end portion of the second region G2 are held by the holding member such as a grip piece, so that a force toward the rear surface G2b side acts on the second region G2.

In the first embodiment, the suction pressure when the unnecessary region G2 is sucked by the suction member 62 is set to be lower as it is located on the upper side in the longitudinal direction of the sheet glass G so that the upper end region G2U protrudes toward the front surface G2a, and in the third embodiment, the effective region G1 is brought into contact with the upper convex portion 33 of the back surface support member 3 and the lower convex portion 43 of the pressing member 4 so that the upper end region G1U protrudes toward the front surface G1a, but the present invention is not limited thereto. The first embodiment may be combined with the third embodiment, and the upper end region G1U, G U may be projected toward the surfaces G1a and G2 a.

In the second embodiment, the suction pressure when the unnecessary region G2 is sucked by the suction member 62 is set to be lower as it is located at the lower side in the longitudinal direction of the sheet glass G so that the lower end region G2L protrudes toward the front surface G2a, and in the fourth embodiment, the effective region G1 is brought into contact with the lower side convex portion 35 of the back surface support member 3 and the upper side convex portion 45 of the pressing member 4 so that the lower end region G1L protrudes toward the front surface G1a, but the present invention is not limited thereto. The second embodiment may be combined with the fourth embodiment such that the lower end regions G1L, G L protrude toward the surfaces G1a and G2 a.

Description of the reference numerals

1. Breaking device

2. Holding mechanism

3. Back support member

6. Adsorption mechanism

62. Adsorption member

G plate glass

G1 First area (effective area)

Surface of G1a first region

Back of G1b first region

G2 Second region (unnecessary region)

Surface of the G2a second region

Back of G2b second region

S-score line

G4 First end surface

G5 Second end face

S1, scribing lines.

Claims (7)

1. A method for producing a sheet glass, comprising a breaking step of breaking a sheet glass in a vertical posture along a scribe line,

the method for manufacturing the plate glass is characterized in that,

the first region and the second region are adjacently arranged in the width direction on the plate glass,

the scribe line is formed at a boundary portion of the first region and the second region and at a surface side of the sheet glass,

in the breaking step, the second region is cut out by applying a force to the second region toward the back surface side in a state in which the first region is supported by a back surface support member from the back surface side contact side of the sheet glass and the second region is sucked and held from the back surface side by a suction mechanism,

and stretching the crack by taking the end part of the scribing line as a starting point.

2. The method for producing a sheet glass according to claim 1, wherein,

the suction mechanism is provided with a plurality of suction members arranged along the scribing line,

in the breaking step, the second region is sucked and held from the back surface side by the suction member, so that a height position as the starting point in the second region protrudes toward the front surface side.

3. The method for producing a sheet glass according to claim 2, wherein,

the upper end of the plate glass is held by a holding mechanism,

the scribing line extends in the up-down direction,

adsorption is started in sequence from the adsorption member located on the upper side among the plurality of adsorption members.

4. A method for producing a sheet glass according to claim 2 or 3, wherein,

the adsorption members of the plurality of adsorption members on the end portion side protruding toward the surface side have lower adsorption pressure than the other adsorption members.

5. The method for producing a sheet glass according to any one of claims 1 to 4, wherein,

in the breaking step, the first region is brought into contact with the back surface support member, so that a height position of the first region as the starting point protrudes toward the front surface side.

6. A device for manufacturing plate glass is provided with a breaking device for breaking plate glass in a vertical posture along a scribing line,

the apparatus for manufacturing a sheet glass is characterized in that,

the first region and the second region are adjacently arranged in the width direction on the plate glass,

the scribe line is formed at a boundary portion of the first region and the second region and at a surface side of the sheet glass,

the breaking device is provided with: a back support member that supports the first region from a back side contact of the sheet glass; an adsorption mechanism that adsorbs and holds the second region from the back surface side; and a pressing member that applies a force to the second region toward the rear surface side,

the breaking device is configured to propagate a crack starting from an end of the scribe line.

7. A sheet glass having two first end faces extending in a drawing direction and two second end faces extending in a width direction intersecting the drawing direction and having a rectangular shape,

the sheet glass is characterized in that,

at least one of the first end faces is a cut-off face formed by breaking and has a scribing line trace,

the starting point of the break is located at the end of the scribe line.