JP2014001130A - Cutting method of belt-like glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem peculiar to online-cutting of belt-like glass (glass ribbon) using a laser beam.SOLUTION: In a cutting method of belt-like glass 10, an interval between a scribe position and a division position is set so that at least one scribe line 11a exists in the belt-like glass 10 conveyed between the scribe position and the division position over a period after the belt-like glass 10 starts to be displaced from a reference conveying surface 60a until it is divided at a scribe line 11x and returned to the reference conveying surface 60a. The scribe line 11a existing in the belt-like glass 10 between the scribe position and the division position relaxes vibration of the belt-like glass 10 generated at the time of cutting.

Description

  The present invention relates to a method for cutting strip glass (glass ribbon).

  The cutting of the plate glass (glass plate) is usually performed using a cutter. When mechanical stress is applied to the scribe line on the glass surface formed by the cutter, the plate glass is divided along the scribe line.

  It has been proposed to apply cutting using a cutter to a sheet glass production line. The cutting performed on the production line is sometimes referred to as “online cutting” to distinguish it from the cutting of the glass sheet taken out of the manufacturing line (cutting outside the manufacturing line is called “offline cutting”). In on-line cutting, a strip-shaped glass that is formed into a predetermined thickness in a forming apparatus and flows on a production line is a cutting target. The band-shaped glass is unloaded from a forming apparatus (for example, a float bath), and while being conveyed on the production line, a scribe line is formed at least in the width direction at a predetermined position, and further, a predetermined scribe line is formed along the scribe line on the downstream side. Divided into plate glass (glass plate) of size. In one example, a scribing line is formed by using a cutter, and a mechanical stress is applied to the scribing line by bending the band-shaped glass by moving a region where the scribe line is formed by a moving roller in the thickness direction. Is divided along the scribe line.

  In online cutting, the strip glass may be naturally separated at the scribe line upstream of the position in the transport direction from the position where the strip glass is to be divided along the scribe line (dividing position) due to vibration caused by the conveyance. . This phenomenon should be avoided because the glass tends to be damaged (especially an edge) when the glass plate formed by dividing the band glass is compared with the time when the band glass is conveyed. This phenomenon is more likely to occur as the distance between the position where the scribe line is formed (scribe position) and the dividing position becomes larger. Therefore, the distance between the scribe position and the divided position is usually between the scribe position and the divided position. Is set small enough that no scribe line exists.

  Further, off-line cutting using a laser beam has also been proposed. In this method, a method of extending the initial crack on the surface of the sheet glass by laser light irradiation and refrigerant injection is employed. When a coolant is sprayed onto a region heated by laser light irradiation and rapidly cooled, tensile stress is generated in the region. When this tensile stress is generated near the tip of the crack, the crack extends. When the surface where the laser light is irradiated and the region where the coolant is blown are scanned in this order in the direction in which the crack is to be extended, a scribe line is formed in the plate glass. Thereafter, mechanical stress is applied to the scribe line in the same manner as described above, and the plate glass is divided along the scribe line (see, for example, Patent Document 1). Advantages of a cutting method using laser light include that even a very thin glass can be cut without any problem, and that the smoothness of the cut surface of the glass is excellent.

JP 2008-142979 A

  When cutting using laser light is applied to online cutting, the depth of the scribe line may not be constant, and the smoothness of the cut surface may deteriorate instead. In online cutting, the strip glass vibrates with conveyance, and therefore the position in the thickness direction of the strip glass may be out of the position where it can be efficiently heated by the laser beam (out of the depth of focus) at the scribe position. Because.

  The above problem can be solved by designing the optical system of the laser light so that the position in the thickness direction of the strip glass at the scribe position is within the focal depth of the laser light, taking into account the amplitude of vibration accompanying the conveyance. Seems like. However, according to the study by the present inventors, the above problem may not be solved even if the laser light optical system is designed in this way. This is because the vibration of the band-shaped glass generated at the time of the division at the division position propagates to the scribe position. That is, a large pulse-like vibration generated at the time of division propagates to the scribe position, and the region scanned by the laser beam in the belt-like glass moves greatly in a pulse shape in the thickness direction. As a result, the depth of the scribe line may become unstable or the formation of the scribe line may be interrupted in the middle.

  It is also conceivable to design an optical system of laser light in consideration of pulse-like vibration generated at the time of division. However, according to the study by the present inventors, the amplitude of the vibration generated at the time of the division is larger than the amplitude of the vibration caused by the conveyance. . Furthermore, since it is necessary to ensure a long optical path, the apparatus must be enlarged and the refrigerant must be injected from a distant position. Therefore, it is desirable to apply another solution in order to solve the problem caused by the vibration generated at the time of division.

  In online cutting using a cutter, a scribe line is formed in the belt-like glass while suppressing the belt-like glass. Therefore, the displacement of the belt-like glass at the scribe position due to the vibration derived from the conveyance and division does not matter.

  In view of the above, an object of the present invention is to improve a method for cutting a strip glass using a laser beam so as to solve a problem specific to online cutting using a laser beam.

The present invention
The initial cracks formed in the band glass are removed from the forming apparatus by supplying a laser beam and a coolant to the band glass while conveying the band glass along the reference conveyance surface in the conveyance direction. A laser scribing step for forming a scribe line in the strip glass by extending in the width direction of
A region that straddles the scribe line at a dividing position that is separated from the scribe position where the scribe line is formed at a predetermined distance away from the scribe position where the scribe line is formed while conveying the glass strip formed with the scribe line. A glass cutting step of displacing the belt-like glass in the scribe line by displacing the belt-like glass from the reference transport surface,
In the glass cutting step, the strip glass is transported between the scribing position and the cutting position over a period from when it starts to be displaced from the reference transport surface until it is split at the scribe line and returns to the reference transport surface. The predetermined interval is determined so that at least one scribe line is present in the belt-shaped glass.
A method for cutting a strip glass is provided.

  The scribe line existing in the strip glass conveyed between the scribe position and the dividing position alleviates the vibration of the strip glass generated at the time of cutting. Therefore, according to the present invention, it is possible to irradiate the strip glass with the laser light in a state where the vibration of the strip glass at the scribe position is relaxed.

It is a top view of the strip glass for demonstrating embodiment of this invention. It is II-II sectional drawing of FIG. FIG. 3 is a partially enlarged view near the head of FIG. 2. It is a top view of the strip glass which shows the area | region where a crack expand | extends. It is an enlarged view of a scribe line. It is a figure for demonstrating the division | segmentation process of a strip glass. It is the elements on larger scale of each scribe line. It is a figure which shows the end surface of the glass plate divided | segmented by supplying a laser beam and a refrigerant | coolant to the strip-shaped glass in the inclined state. It is a figure which shows the end surface of the glass plate divided | segmented by supplying a laser beam and a refrigerant | coolant to the strip glass in a horizontal state. It is a top view of the strip glass for demonstrating reference embodiment A1. It is II-II sectional drawing of FIG. FIG. 12 is a partially enlarged view near the head of FIG. 11. It is a top view of the strip glass which shows the area | region where a crack expand | extends. It is a figure for showing an example of a glass parting step. It is a top view of the strip glass for demonstrating reference embodiment A2. It is a figure which shows a mode that an initial stage crack expands in experiment A1. It is a graph which shows the relationship between the thickness of plate glass, and the moving speed of a conveyance table when a scribe line is formed. It is a graph which shows the relationship between the conveyance speed of the strip | belt-shaped glass assumed, and the movement speed of a conveyance table when a scribe line is formed. It is a top view of the strip glass for demonstrating reference embodiment B1. It is a figure for showing an example of a mode that the position of the thickness direction of strip glass changes. It is II-II sectional drawing of FIG. It is the elements on larger scale near the head of FIG. It is a figure for demonstrating a mode that a laser beam and a refrigerant | coolant are supplied to the surface of a strip glass. It is a top view of the strip glass which shows the area | region where a crack expand | extends. It is a figure for demonstrating the shape of the laser beam after passing an optical system. It is a figure for showing an example of a glass parting step. It is a figure for demonstrating a mode that a laser beam and a refrigerant | coolant are supplied to the surface of a strip glass. It is a figure which shows a mode that an initial stage crack expands in experiment B1. It is a graph which shows the relationship between the height of an optical system and a nozzle, and the moving speed of a conveyance table when a scribe line is formed. It is a figure which shows a mode that a laser beam and a refrigerant | coolant are supplied to plate-like glass in the experiment in offline. It is a figure which shows a mode that a laser beam and a refrigerant | coolant are supplied to plate-like glass in the experiment in offline. It is a figure which shows a mode that a laser beam and a refrigerant | coolant are supplied to plate-like glass in the experiment in offline. It is a top view of the strip glass for demonstrating reference embodiment C1. It is II-II sectional drawing of FIG. FIG. 35 is a partially enlarged view of the vicinity of the head of FIG. 34. It is a top view of the strip glass which shows the area | region where a crack expand | extends. It is a figure for demonstrating a Gaussian type energy density profile. It is a figure for demonstrating a ring type energy density profile. It is a figure for demonstrating an energy density profile of a top hat type. It is a figure for showing an example of a glass parting step. It is a top view of the strip glass for demonstrating reference embodiment C2. It is a figure for showing an example of the glass cutting step in reference embodiment C2. It is a figure which shows a mode that an initial stage crack expands in experiment C1. It is a photograph which shows the cross section of the acrylic board heated with the laser beam in experiment C1. It is a graph which shows the relationship between the height of an optical system and a nozzle, and the moving speed of a conveyance table when a scribe line is formed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a state in which a band-like glass (glass ribbon) 10 that is unloaded from a glass forming apparatus and is transported along a reference transport surface that is a horizontal surface is observed from above. The strip glass 10 is formed to a predetermined thickness in a glass forming apparatus (not shown; for example, float bath) installed on the upstream side in the transport direction 40 (upstream side of the region shown in FIG. 1). Are transported at a constant speed. The belt-shaped glass 10 is transported by a transport roller 21 that supports the belt-shaped glass 10 from below. In the present embodiment, the conveyance surface constituted by the conveyance rollers 21 is referred to as a reference conveyance surface. In addition, when the strip | belt-shaped glass 10 is thin, it is preferable to make the pitch of the conveyance roller 21 fine. Further, a conveyance belt may be used instead of the conveyance roller 21.

  A scribe line 11 is formed on the belt-like glass 10 by a scribe line forming head (hereinafter simply referred to as “head”) 51 that traverses the glass strip 10. The scribe line 11 is formed so as to extend in parallel to the width direction 41 of the strip glass 10 orthogonal to the transport direction 40 and to maintain a predetermined interval in the transport direction 40. The band-shaped glass 10 is divided at the scribe line 11 by the cutting device (moving roller 25) arranged on the downstream side in the transport direction 40 to become a glass plate 100.

  In order to form the scribe line 11 parallel to the width direction 41 of the glass strip 10, the head 51 runs obliquely with respect to the width direction 41. The oblique traveling direction 42 and the width direction 41 of the head 51 form an angle θ that is determined depending on the conveyance speed of the belt-like glass 10 and the traveling speed of the head 51. The head 51 travels at a constant speed by being guided by a guide (not shown) that crosses the upper portion of the glass strip 10 in parallel with the oblique traveling direction 42. For convenience, the line on which the head 51 travels is shown in FIG.

  1 along the head travel line 50 is shown in FIG. 2, and a partially enlarged view of FIG. 2 is shown in FIG. The head 51 includes an optical system 70 for condensing laser light on the strip glass 10 and an injection nozzle 80 for locally cooling the strip glass 10 by ejecting a coolant. The head 51 further includes a cutter 19 that is a crack forming device that forms an initial crack in the belt-like glass 10.

  The cutter 19 is typically a wheel cutter, but there is no particular limitation on the type thereof as long as it can form a stretchable crack in the strip glass 10. The cutter 19 plays a role of forming an initial crack, which is a starting point of the scribe line 11, in the strip glass 10. The initial crack is formed at the end of the strip glass 10 (in the case of the strip glass 10 shown in FIG. 1, the right end in the drawing) or in the vicinity thereof.

  The cutter 19 is pressed against the surface (upper surface) of the strip glass 10 by a cutter pressing device (not shown) when the initial crack is formed. Since the support 22 supports the glass strip 10 at a position along the head travel line 50, a reaction force is applied from the cutter 19 to the glass strip 10 by this pressing. However, this pressure is released after the formation of the initial crack, and as a result, as shown in FIG. 3, the cutter 19 is typically not in contact with the strip glass 10.

  The initial crack extension for forming the scribe line 11 is performed by the laser beam 17 and the coolant 18 supplied from the head 51. In other words, if heating by the laser beam 17 and rapid cooling by the refrigerant 18 are successively applied to the end of the crack, a tensile stress is generated on the glass surface in the vicinity of the crack, and the crack extends due to this tensile stress. The head 51 advances on the head travel line 50 (to the left in the illustrated form) while extending the crack. In the present embodiment, the head travel line 50 corresponds to the scribe position.

  As shown in FIG. 4, as the head 51 travels, the belt-shaped glass 10 is irradiated with the laser beam 17 via the optical system 70, and the coolant 18 is supplied from the injection nozzle 80. The region 28 proceeds on the head travel line 50 in this order. In other words, these regions travel on the head travel line 50 while the cooled region 28 follows the irradiated region 27. The head 51 maintains the relative positional relationship between the laser beam condensing device (optical system 70) that forms the irradiated region 27 and the cooling device (jet nozzle 80) that forms the cooled region 28. The role to move is left. As the head 51 travels, a scribe line 11 as shown in FIG. 5 is formed.

Returning to FIG. 3, the laser light irradiation system and the refrigerant supply system will be briefly described. However, these systems can be used without any particular limitation. The laser beam 17 is condensed from the laser beam generator 71 to the irradiated region 27 of the strip glass 10 via the laser beam expanding device 72 and the condensing device (optical system 70) in the head 51. The optical system 70 includes mirrors and other optical elements 73, 74, and 75. As the laser beam 17, a CO ₂ laser, a YAG laser, or the like can be used. The refrigerant 18 is supplied from a refrigerant supply device (not shown) to the area to be cooled 28 via an injection nozzle 80 provided in the head 51. For example, air, nitrogen, helium, or water may be used as the refrigerant.

  As shown in FIGS. 6A to 6C, the band-like glass 10 on which the scribe line 11 is formed is along the scribe line 11 x (the scribe line 11 on the most downstream side in the conveyance direction) on the downstream side in the conveyance direction 40. Divided. Specifically, when the scribe line 11x of the strip glass 10 approaches, the moving roller 25 lifts the strip glass 10 in the thickness direction (FIGS. 6A and 6B). The strip glass 10 is cleaved along the cracks constituting the scribe line 11x by the stress generated by the weight of the lifted strip glass 10, and the downstream side thereof is divided into the glass plate 100. More specifically, the moving roller 25 lifts the belt-like glass 10 so that the amount of displacement of the portion in contact with the moving roller 25 is maximized, and advances the division at the scribe line 11x. After the division is completed, the moving roller 25 is pulled down to prepare for the next division (FIG. 6C).

  In order to apply stress to the scribe line 11x, the moving roller 25 has the back surface of the glass strip 10 on the back surface in the region straddling the scribe line 11x, that is, both the upstream side (left side in the figure) and the downstream side (right side in the figure). While being supported, it is lifted upward and displaced from the reference transport surface (FIG. 6B). Thereafter, as the moving roller 25 descends, the downstream end 10e of the strip glass 10 once moved upward returns to the lower side (FIG. 6C). In the present embodiment, the position where the moving roller 25 is provided corresponds to the dividing position.

  In this embodiment, the cutting at the scribe line 11 is caused to proceed by the stress generated by its own weight. However, when the moving roller 25 is raised, the strip glass 10 is moved upstream or downstream in the conveying direction 40 of the moving roller 25. The cutting may be advanced by pressing the surface from above. If it does in this way, even if it is a case where the thin and light strip glass 10 is parted, it is easy to ensure the stress required for parting.

  In the present embodiment, in the glass cutting step, the strip glass 10 starts to be displaced from the reference conveyance surface (conveyance height 60a) and then is divided at the scribe line 11x (reaches the division height 60b) until it returns to the reference conveyance surface. The interval between the scribe position and the dividing position is determined so that the scribe line 11 exists in the belt-shaped glass 10 being conveyed between the scribe position and the dividing position over the period. The cracks constituting the scribe line 11 can absorb vibrations generated during the dividing process due to fluctuations in the width thereof. Therefore, according to the configuration of the present embodiment, the vibration of the strip glass 10 at the scribe position is reduced.

  In the example shown in FIGS. 6A to 6C, two scribe lines 11b are formed on the belt-like glass 10 being conveyed along the reference conveyance surface (conveyance height 60a) between the scribe position and the dividing position. 11c exists, thereby effectively mitigating vibration of the glass strip 10 at the scribe position.

  Of the two scribe lines 11b and 11c existing in the belt-like glass 10 conveyed along the conveyance height 60a between the scribe position and the dividing position, the vibration is effectively mitigated by the above configuration. This is because the width of the cracks constituting the scribe line 11c located on the upstream side in the transport direction is difficult to narrow when the moving roller 25 is raised. This point will be described with reference to FIGS. 7A to 7C which are partially enlarged views of FIG. The width of the crack constituting the scribe line 11a adjacent to the scribe line 11x on the upstream side in the transport direction is narrowed when the moving roller 25 is raised (FIG. 7A). This is because the strip glass 10 is lifted on the downstream side of the scribe line 11a in the conveying direction, and the strip glass 10 is bent. In the scribe line 11a in this state, when the band-like glass 10 is displaced upward (in the direction in which the bending is eliminated) in the scribe line 11a due to vibration, the width of the crack is widened, so that the vibration suppressing action is exhibited and the vibration is increased. Is prevented. The width of the crack constituting the scribe line 11b adjacent to the scribe line 11a on the upstream side in the conveying direction is also reduced when the moving roller 25 is raised (FIG. 7B). This is because the scribe line 11b itself exists on the belt-shaped glass 10 being transported at the transport height 60a, but the strip-shaped glass 10 is lifted from the transport height 60a between the scribe line 11a and the scribe line 11b. On the other hand, the width of the scribe line 11c adjacent to the scribe line 11b on the upstream side in the transport direction is hardly affected even when the moving roller 25 is raised. As described above, since the width of the crack constituting the scribe line 11c is maintained even when the moving roller 25 is raised, the scribe line 11c causes cracks when the strip glass 10 is displaced upward in the scribe line 11c due to vibration. Not only does the width increase, but the width of the crack is reduced when it is displaced downward, whereby the vibration suppressing action is more effectively exhibited and the increase in vibration is more effectively prevented.

  Even when the number of the scribe lines 11 in the belt-like glass 10 being conveyed at the conveyance height 60a between the scribe position and the dividing position is more than two, the same effect as described above can be obtained.

  According to the study by the present inventors, in the on-line cutting using a laser beam, the phenomenon that the strip glass naturally separates along the scribe line hardly occurs. That is, in online cutting using laser light, the restriction on the upper limit of the interval between the dividing position and the scribe position is relaxed. This is likely due to the fact that when a scribe line is formed using a laser beam, horizontal cracks are less likely to be formed in the belt-like glass than when a scribe line is formed using a cutter.

  However, when the number of the scribe lines 11 in the belt-like glass 10 conveyed between the scribe position and the dividing position is excessively large, that is, when the interval between the scribe position and the dividing position is excessively large, laser light is used. Even if the scribe line is formed, the glass plate 100 may be formed by being naturally divided before the band-like glass 10 reaches the dividing position due to vibration accompanying conveyance. Therefore, the upper limit of the number of the scribe lines 11 in the belt-like glass 10 conveyed between the scribe position and the dividing position may be set to 20, for example, preferably 10, and more preferably 5.

  Moreover, in this embodiment, as shown to Fig.6 (a)-(c), until the strip glass 10 begins to move upward from conveyance height 60a in a dividing position, it is divided and returns to conveyance height 60a. Over the period, only the lower surface of the glass strip 10 is supported between the scribe position and the split position. Accordingly, during this period, the glass strip 10 is not pressed from the upper surface, and the surface thereof is not damaged.

  Further, as shown in FIG. 8 (a), the scribe line 11 formed by irradiating the belt-shaped glass 10 in an inclined state with the laser light 17 and injecting the refrigerant 18 is perpendicular to the glass surface. Don't be. The end surface of the glass plate 100 formed by dividing the strip glass 10 by the scribe line 11 that runs obliquely from the surface to the inside does not become flat but has a bent shape. This is because the stress that is divided by the scribe line 11 is applied perpendicularly to the surface of the glass (see FIG. 8B), and the crack is elongated while being bent in the middle. On the other hand, in this embodiment, since the scribe position and the dividing position are sufficiently separated from each other, the glass strip 10 at the scribe position is not lifted upward and tilted with the movement at the dividing position. That is, the strip glass is moved to the reference transport surface at the scribe position over a period from when the strip glass 10 starts to move upward from the transport height 60a to the transport height 60a and returns to the transport height 60a. Since the state along is maintained, the glass strip 10 at the scribe position is surely leveled when the laser beam 17 is irradiated and when the refrigerant 18 is injected (FIG. 9A). Therefore, it becomes easy to form the scribe line 11 perpendicular to the surface of the glass, and the end surface of the glass plate 100 can be easily flattened (FIG. 9B). Thus, according to this embodiment, the quality of the end surface of the glass plate 100 is easy to be ensured.

  In addition, the thickness of the strip glass 10 is not particularly limited, but is, for example, 0.1 mm to 5 mm. In particular, when the thickness is 0.1 mm to 1.1 mm, the influence of vibration on the cut surface of the glass is increased, so the effect of applying the present invention is also increased.

  The distance between the scribe position and the dividing position is not particularly limited, but is, for example, 2 m to 10 m, and for example, 2 m to 5 m.

  When the scribe line 11 is formed in a direction (width direction 41) crossing the strip glass 10, the moving speed of the head 51 needs to be set high. Therefore, since the influence of vibration on the formation of the scribe line 11 is increased, the effect of interposing the scribe line 11 between the scribe position and the dividing position is increased.

(Reference Embodiment A1)
By the way, an apparatus disclosed in Patent Document X (Japanese Patent Publication No. 2010-526014) includes a carriage (head) that moves along a linear slide member that is attached so as to cross the transport path of the belt-like glass. Yes. This head irradiates the strip glass with laser light while traversing the strip glass, and continuously supplies the coolant to the region irradiated with the laser light. Thus, a scribe line is formed along the width direction of the strip glass.

In the linear slide member of Patent Document X, the direction in which the linear slide member extends is set to a direction that forms a predetermined angle θ (angle α) with the width direction of the strip glass. The angle θ is such that the scribe line extends in the width direction of the strip glass (so that the transport direction component V _hx of the strip glass at the head moving speed V _h matches the transport speed V _g of the strip glass). Are adjusted together with the transport speed V _g of the head and the moving speed V _{h of the} head.

  There are various uses of the glass plate to be sampled, and each user is required to provide a glass plate having a thickness corresponding to each application. From the viewpoint of meeting the above requirements while suppressing the capital investment on the production line, it is preferable to sample the glass plates of each thickness with a single cutting device. However, it is not always easy to form a scribe line in each thickness of glass strip with a single cutting device.

  According to the study by the present inventors, the amount of heat to be given to the strip glass by the laser beam varies depending on the thickness of the strip glass. Therefore, in order to form a scribe line in each thickness of strip glass with a single cutting device, adjustment is required to give the strip glass a heat quantity corresponding to the thickness. In order to adjust the amount of heat given to the strip glass, it is conceivable to adjust the output of the laser beam. However, according to the study by the present inventors, it is difficult to form a scribe line in each thickness of glass strip only by adjusting the output of the laser beam.

Next, the present inventors examined adjusting the amount of heat given to the strip glass by adjusting the width direction component V _hy of the strip glass at the moving speed V _h of the head. As a result of the investigation, it was found that the width direction component V _hy has a range suitable for forming a scribe line, and that this range varies depending on the thickness of the strip glass. From this viewpoint, it is conceivable to adjust the angle θ and the moving speed V _{h of the} head for each thickness of the strip glass. However, such adjustment, particularly the adjustment of the angle θ, is complicated. In particular, in a production line that employs the float method, the range of the thickness of the strip glass to be cut is wide, and the complexity becomes significant.

  In view of the above circumstances, the present inventors disclose a cutting method in which a scribe line can be formed on each glass strip with a simple configuration in which the number of settable angles θ is limited to two or less. .

  Hereinafter, Reference Embodiment A1 will be described with reference to the drawings. In the following description, the same member is denoted by the same reference numeral in each drawing, and the description may be omitted.

  FIG. 10 shows a state in which a strip glass (glass ribbon) 110 carried out from the glass forming apparatus and conveyed in the horizontal direction is observed from above. The band-shaped glass 110 is formed to a predetermined thickness in a glass forming apparatus (not shown) installed on the upstream side in the transport direction 140 (upstream side of the region shown in FIG. It is being conveyed by.

Specifically, the strip glass 110 is a strip glass in the float process, and is molded in a float bath. In the float process, the conveyance speed V _g of the strip glass 110 is determined in accordance with the thickness of the strip glass 110 to be formed. The range of the thickness of the band-shaped glass 110 that is the object of the present embodiment is a range of T _min or more and T _max or less over 0.4 mm, for example, 0.28 to 1.1 mm.

  Moreover, the strip | belt-shaped glass 110 of this embodiment is soda-lime glass, and displays each mass% and has each component of the following range.

SiO ₂ : 65-80%
Al ₂ O ₃ : 0 to 5%
MgO: 1-10%
CaO: 5 to 15%
Na ₂ O: 10 to 18%
K ₂ O: 0 to 5%
B ₂ O _3: 0~5%
MgO + CaO: 6-15%
Na ₂ O + K ₂ O: 10 to 20%

  The belt-shaped glass 110 is transported by a transport roller 121 that supports the belt-shaped glass 110 from below. In addition, when the strip | belt-shaped glass 110 is thin, it is preferable to make the pitch of the conveyance roller 121 fine. Further, instead of the transport roller 121, a transport belt may be used.

  A scribe line 111 is formed on the belt-like glass 110 by a scribe line forming head (hereinafter simply referred to as “head”) 151 or a scribe line forming head (hereinafter simply referred to as “head”) 251 traversing the glass strip 110. The scribe line 111 is formed so as to extend in parallel to the width direction 141 of the strip glass 110 orthogonal to the transport direction 140 and to maintain a predetermined interval in the transport direction 140. The band-shaped glass 110 is divided at the scribe line 111 by the dividing device (moving roller 125) disposed on the downstream side in the transport direction 140 to become the glass plate 200.

In order to form the scribe line 111 parallel to the width direction 141 of the strip glass 110, the head 151 and the head 251 run obliquely with respect to the width direction 141. The oblique traveling direction 142 and the width direction 141 of the head 151 form an angle θ1 determined depending on the transport speed V _g of the belt-like glass 110 and the traveling speed V _h1 of the head 151, and the oblique traveling direction 242 and the width direction. 141 forms an angle θ2 that is determined depending on the conveyance speed V _g of the belt-like glass 110 and the traveling speed V _h2 of the head 251. The oblique traveling direction 142 is a direction determined so that the scribe line 111 can be formed on the belt-like glass 110 having a thickness T _min , and the oblique traveling direction 242 is a direction determined so that θ2 is less than θ1. It is. In the present embodiment, the oblique traveling direction 142 and the oblique traveling direction 242 are set by a transverse direction setting step (described later).

  The head 151 is guided by a guide (not shown) that traverses the upper portion of the strip glass 110 in parallel to the skew travel direction 142 and travels at a constant speed. The head 251 is parallel to the skew travel direction 242 and travels at the strip glass. The vehicle travels at a constant speed while being guided by a guide (not shown) that crosses over 110. For convenience, the line on which the head 151 travels is shown as a head travel line 150 and the line on which the head 251 travels is shown as a head travel line 250 in FIG. The head 151 and the corresponding guide constitute a crack extension device. The head 251 and the corresponding guide also constitute a crack extension device. In this embodiment, there are two crack extension devices, but the number of crack extension devices may be one. In the case where the number of crack extension devices is one, for example, by providing one end of the guide so as to be pivotable, the head traveling direction is selectively selected from the oblique traveling direction 142 and the oblique traveling direction 242. It can be set.

  FIG. 11 is a cross-sectional view of FIG. 10 along the head travel line 150, and FIG. 12 is a partially enlarged view of FIG. 11 (the same is true of the cross-sectional view of FIG. 10 along the head travel line 250). The head 151 and the head 251 include an optical system 170 for condensing the laser light on the strip glass 110, and an injection nozzle 180 for locally cooling the strip glass 110 by jetting a coolant. The head 151 and the head 251 further include a cutter 119 that is a crack forming device that forms an initial crack in the belt-like glass 110.

  The cutter 119 is typically a wheel cutter, but there is no particular limitation on the type of the cutter 119 as long as it can form a stretchable crack in the strip glass 110. The cutter 119 plays a role of forming an initial crack serving as a starting point of the scribe line 111 in the strip glass 110. The initial crack is formed at or near the end of the strip glass 110 (in the case of the strip glass 110 shown in FIG. 10, the right end in the figure).

  The cutter 119 is pressed against the surface (upper surface) of the strip glass 110 by a cutter pressing device (not shown) when the initial crack is formed. The support body 122 supports the glass strip 110 at a position along the head travel line 150 and the support body 222 supports the glass strip 110 at a position along the head travel line 250. Power is added. However, this pressure is released after the formation of the initial crack, and as a result, as shown in FIG. 12, the cutter 119 is typically not in contact with the strip glass 110.

  The initial crack extension for forming the scribe line 111 is performed by the laser beam 117 and the coolant 118 supplied from the head 151 or the head 251. That is, if heating by the laser beam 117 and rapid cooling by the refrigerant 118 are applied successively at the end of the crack, a tensile stress is generated on the glass surface in the vicinity of the crack, and the crack extends due to this tensile stress. The head 151 advances on the head travel line 150 (in the illustrated form, to the left in the figure) while extending the crack, and the head 251 also performs the head travel line 250 while extending the crack in the same manner as the head 151. Go up (crack extension step). In the present embodiment, a crack that is formed by extending an initial crack and that can cut the glass strip 110 along the crack in the glass cutting step is referred to as a scribe line 111.

  As shown in FIG. 13, as the head 151 travels, the belt-shaped glass 110 is irradiated with the laser beam 117 via the optical system 170, and the coolant 118 is supplied from the injection nozzle 180. The region 128 proceeds on the head travel line 150 in this order. In other words, the region to be cooled 128 follows the irradiated region 127 while these regions travel on the head travel line 150. The head 151 maintains the relative positional relationship between the laser beam condensing device (optical system 170) that forms the irradiated region 127 and the cooling device (jet nozzle 180) that forms the cooled region 128. The role to move is left. The role played by the head 251 is the same.

Returning to FIG. 12, the laser light irradiation system and the refrigerant supply system will be briefly described. However, these systems can be used without any particular limitation. The laser beam 117 is condensed from the laser beam generator 171 to the irradiated region 127 of the belt-like glass 110 via the laser beam expanding device 172 and the condensing device (optical system 170) in the head 151 (head 251). The The optical system 170 includes mirrors and other optical elements 173, 174, and 175. As the laser beam 117, a CO ₂ laser, a YAG laser, or the like can be used. The refrigerant 118 is supplied from a refrigerant supply device (not shown) to the cooled region 128 via the injection nozzle 180 provided in the head 151 (head 251). For example, air, nitrogen, helium, or water may be used as the refrigerant.

  Note that the output of the laser beam is not particularly limited, but is typically 30 W or more and 60 W or less. When the output of the laser beam is excessively large, the strip glass 110 may be completely divided or an unintended crack (for example, a crack extending in a direction other than a desired direction) may occur. On the other hand, if it is too small, it is difficult to extend the initial crack.

  The length of the irradiated region 127 is, for example, 15 mm or more and 30 mm or less. Further, the width of the irradiated region 127 is, for example, not less than 0.1 mm and not more than 3.0 mm.

  The strip glass 110 on which the scribe line 111 is formed is divided along the scribe line 111 on the downstream side in the transport direction 140 (glass cutting step). As shown in FIGS. 14A and 14B, when the scribe line 111 of the strip glass 110 approaches, the moving roller 125 lifts the strip glass 110 in the thickness direction. Cracks constituting the scribe line 111 are extended by the stress generated by the weight of the raised glass strip 110, and the glass strip 110 is cleaved. More specifically, the moving roller 125, which is a glass cutting device, lifts the strip glass 110 so that the amount of displacement of the portion in contact with the moving roller 125 is maximized, and advances the cutting along the scribe line 111. As shown in FIG. 14C, after the division is completed, the moving roller 125 is pulled down to prepare for the next division.

  In order to apply stress to the scribe line 111, the moving roller 125 moves upward while supporting the back surface of the glass strip 110 on both the upstream side (left side in the figure) and the downstream side (right side in the figure) across the scribe line 111. Lifted up (FIG. 14B). As the moving roller 125 subsequently descends, the downstream end 110e of the strip glass 110 once moved upward returns to the lower side (FIG. 14C).

  In the present embodiment, the cutting at the scribe line 111 is advanced by the stress generated by its own weight. However, when the moving roller 125 is raised, the strip glass 110 is moved upstream or downstream in the conveying direction 140 of the moving roller 125. The cutting may be advanced by pressing the surface from above. In this way, even when the thin and light strip glass 110 is divided, it is easy to ensure the stress required for the division.

  In this embodiment, in the crack extension step, when the thickness of the strip glass 110 is less than 0.4 mm, the strip 151 is moved from the head 151 (crack stretcher) that moves in the oblique traveling direction 142 (first transverse direction). When a laser beam and a coolant are supplied to the glass 110 and the thickness of the belt-like glass 110 is 0.4 mm or more, from the head 251 (crack stretching device) that moves in the oblique running direction 242 (second transverse direction). A laser beam and a coolant are supplied to the strip glass 110 to form a scribe line 111 on the strip glass 110. Then, in the glass cutting step, the strip glass 110 is cut along the scribe line 111. In the present embodiment, the oblique traveling direction 142 and the oblique traveling direction 242 are set in the transverse direction setting step that is performed before the crack extension step. Hereinafter, the transverse direction setting step will be specifically described.

  The transverse direction setting step includes a specific sub-step A1, a specific sub-step B1, a determination sub-step C1, and a determination sub-step C2. In this embodiment, these substeps are performed in this order. However, the specific substep A1 may be performed after the specific substep B1.

In the specifying sub-step A1, an upper limit value V _hy1MAX of the width direction component V _hy1 of the moving speed V _h1 of the head 151 capable of forming the scribe line 111 on the strip glass 110 having a thickness of T _min is specified. The specific sub-step A1 irradiates the plate glass with the laser beam while moving the laser beam at a relative speed V _R1 relative to the plate glass having a thickness of T _min , for example. In an off-line experiment in which a scribe line is formed on glass, the upper limit value of the relative speed V _{R1 at which} the scribe line can be formed may be measured.

In the specifying sub-step B1, the lower limit value V _hy1MIN of the width direction component V _hy1 of the moving speed V _h1 of the head 151 capable of forming the scribe line 111 on the strip glass 110 having a thickness of T _min is specified. Similar to the specific sub-step A1, the specific sub-step B1, for example, moves the laser light to the plate glass while moving the laser light relative to the plate glass having a thickness of T _{min at} a relative speed V _R1. In an off-line experiment in which irradiation is performed and a scribe line is formed on the sheet glass, the lower limit of the relative speed V _{R1 at which} the scribe line can be formed may be measured.

In decision sub-step C1, conveying thickness of the ribbon of T _min speed V _g1, the upper limit value V _Hy1MAX and the lower limit value _{V hy1MIN, arctan {(V g1} ) / (V hy1MAX)} ≦ θ1 ≦ arctan {(V _The angle θ1 is determined so as to satisfy _g1 ) / ( _Vhy1MIN )}. In the present embodiment, since the molded glass ribbon 110 by the float process, the thickness of the conveying speed V _g1 of the ribbon 110 of T _min is determined in accordance with the thickness T _min.

Further, in the present embodiment, θ1 is determined to be a value within a range satisfying arctan {(V _g1 ) / (V _hy1MAX )} ≦ θ1 ≦ arctan {(V _g1 ) / (V _hy1MAX × K)}. Here, K is, for example, 0.6, 0.7, 0.8, or 0.9.

In the determination substep C2, the angle θ2 is determined so as to satisfy θ2 <arctan {(V _g1 ) / (V _hy1MAX )}.

In the determination sub-step C2, it is preferable to determine θ2 so that θ2 is prevented from becoming too small. For this purpose, for example, the plate glass is irradiated with the laser light while moving the laser light at a relative speed V _R2 relative to the plate glass having a thickness of 0.4 mm. moving in an off-line experiment of forming a scribe line, the said scribe line was measured the upper limit of formable relative speed V _R2 the thickness can form a scribe line 111 on the ribbon 110 of 0.4mm head 251 The upper limit value V _hy2MAX of the width direction component V _hy2 of the speed V _h2 is specified, and from the conveyance speed V _g2 and the upper limit value V _hy2MAX of the strip glass having a thickness of 0.4 mm, θ2 ≧ arctan {(V _g2 ) / (V _hy2MAX )} may be determined so as to satisfy.

In order to be able to form the scribe line 111 on the strip-shaped glass 110 of each thickness, the angle θ between the width direction 141 and the oblique running direction needs to be not less than each lower limit and not more than each upper limit. . As will be understood from the following discussion, if the angle θ is set so that the scribe line 111 can be formed on the strip glass 110 having a thickness of T _min , the scribe line is formed on the strip glass having a thickness of T _{min to} T _max. 111 can be formed. That is, according to the cutting method of this embodiment, the scribe line 111 can be reliably formed on the strip-shaped glass 110 of each thickness by a single cutting device.

By the way, the band-like glass 110 on which the scribe line 111 is formed may be naturally divided by the vibration accompanying the conveyance before the glass dividing step is performed. From the viewpoint of preventing this, avoid forming the scribe line 111 excessively deep, in other words, lower the angle θ1 so that the width direction component V _hy1 of the moving speed V _h1 of the head 151 can be set higher. It is preferable to set. That is, it is determined from the above viewpoint that θ1 is determined to be a value satisfying arctan {(V _g1 ) / (V _hy1MAX )} ≦ θ1 ≦ arctan {(V _g1 ) / (V _hy1MAX × K)}. It is advantageous. Note that setting θ1 small is also advantageous in that it is difficult to cause a situation in which the degree of freedom in designing the apparatus is reduced (for example, it is easy to narrow the pitch of the conveying rollers 121).

  In addition, when cutting the strip glass using a cutter, since the influence of the width direction component of the strip glass on the movement speed of the cutter on the formation of the scribe line is limited, in cutting the strip glass using the cutter, From the viewpoint of increasing the degree of design freedom of the apparatus, the angle θ is often set small. Considering this point, setting the angle θ1 to be low is a design change when using a cutting device that cuts the glass ribbon using a cutter and is modified to cut the glass ribbon using a laser beam. This is advantageous in that the number of necessary parts can be reduced.

  In the present embodiment, considering that the lower limit value of the angle θ when the thickness is 0.4 mm or more is smaller than the lower limit value of the angle θ when the thickness is less than 0.4 mm (details will be described later), The angle θ2 set as the angle θ when the thickness is 0.4 mm or more is set smaller than the minimum value that can be taken by the angle θ1 set as the angle θ when the thickness is less than 0.4 mm. This also conforms to the above viewpoint of preventing the natural division of the strip glass 110.

(Reference embodiment A2)
FIG. 15 shows a state in which a strip-shaped glass (glass ribbon) 110 that is unloaded from a glass forming apparatus (not shown) and transported in the horizontal direction is observed from above, as in FIG. Since each member has already been described above with reference to FIG. 10, the description thereof is omitted here.

  As shown in FIG. 15, in the reference embodiment A2, there is only a crack stretching device having a head 151 as the crack stretching device. That is, the oblique traveling direction (transverse direction) is only the oblique traveling direction 142. The oblique traveling direction 142 is determined by the specific sub-step A1, the specific sub-step B1, and the determination sub-step C1 described in the reference embodiment A1.

  According to this embodiment, the scribe line 111 can be reliably formed on the strip-shaped glass 110 having each thickness. Further, in the present embodiment, only the crack stretching device having the head 151 exists as the crack stretching device, which is more advantageous than the reference embodiment A1 from the viewpoint of design freedom of the device. This embodiment is particularly suitable when the band-like glass is less vibrated and the risk of natural separation is small.

Hereinafter, an experiment conducted for confirming the relationship between the thickness of the strip glass 110 and the upper limit value and the lower limit value of the width direction component V _hy will be described with reference to FIG.

(Experiment A1)
A soda-lime glass plate having a thickness of 0.28 mm, a short side length of 100 mm, and a long side length of 200 mm as a plate-like glass 410 and indicated by mass% and having the following components was prepared.

SiO ₂ : 71.9%
Al ₂ O ₃ : 1.7%
MgO: 4.0%
CaO: 8.0%
Na ₂ O: 13.5%
K ₂ O: 0.9%

  The plate glass 410 was fixed to the transfer table 490 so that the direction along the long side of the plate glass 410 coincided with the transfer direction 442 of the transfer table 490.

  An initial crack 461 was formed in the sheet glass 410 with the transfer table 490 being stationary. Specifically, an initial crack 461 having a length of 10 mm extending from the one point on one short side 410a of the plate glass 410 toward the short side 410b was formed. The initial crack 461 was formed using a sintered diamond cutter wheel (outer diameter φ2.5 mm, thickness 1.0 mm, inner diameter φ1.1 mm, blade edge angle 135 degrees).

  Next, while moving the transfer table 490, the plate-like glass 410 was irradiated with laser light, and water (refrigerant) was further injected. Specifically, first, the irradiated region 427 and the cooled region 428 are initially set at positions ahead of the short side 410a in the transport direction 442, and the major axis of the initial crack 461 and the major axis of the irradiated region 427 are the same. Then, the position of the transport table 490 was initially set so that no gap was formed between the two long axes. Next, the laser beam condensing device and the cooling device were adjusted so that the irradiated region 427 had a length of 24 mm and a width of 1 mm, and the cooled region 428 was in contact with one end of the irradiated region 427 in the length direction. (FIG. 16A). Next, while maintaining the positions of the irradiated region 427 and the cooled region 428 fixed, the conveying table 490 is moved 120 mm / min in the conveying direction 442 until these positions are downstream of the short side 410b in the conveying direction 442. It was moved at a speed of s (FIGS. 16B and 16C). The depth of the scribe line (crack 462) formed at this time was examined.

Specifically, a 30 W laser beam output from a CO ₂ laser oscillator (ULC-100 manufactured by UNIVERSAL LASER SYSTEMS) is refracted and reflected by using two axicon lenses, a cylindrical lens, and a mirror to be irradiated region 427. It was set. Moreover, the to-be-cooled area | region 428 was set by injecting the water of 1.5 ml / min of injection quantity from a nozzle (Everloy minimist 04-10-13).

  Next, the same experiment was repeated by sequentially changing the moving speed of the transfer table 490. Further, the same experiment (Experiment A1) was performed by sequentially changing the output of the laser beam. The results of Experiment A1 are shown in Table 1. In Table 1, the numerical values other than the moving speed and the output indicate the depth (μm) of the crack (vertical crack) 462 constituting the formed scribe line (for example, Table 1 shows the movement of the transfer table 490). This indicates that a scribe line having a depth of 70 μm was formed when the speed was 216 mm / s and the laser beam output was 30 W). F indicates that the plate-like glass 410 is completely divided, and N indicates that the initial crack 461 does not extend at all.

(Experiment A2)
A similar experiment (Experiment A2) was performed using a plate-like glass 410 having a thickness of 0.33 mm. The results of Experiment A2 are shown in Table 2.

(Experiment A3)
A similar experiment (Experiment A3) was performed using a plate-like glass 410 having a thickness of 0.4 mm. The results of Experiment A3 are shown in Table 3.

(Experiment A4)
A similar experiment (Experiment A4) was performed using a sheet glass 410 having a thickness of 0.7 mm. The results of Experiment A4 are shown in Table 4.

(Experiment A5)
A similar experiment (Experiment A5) was performed using a plate-like glass 410 having a thickness of 1.1 mm. The results of Experiment A5 are shown in Table 5.

  The results of Experiments A1 to A5 indicate that there are a minimum value and a maximum value for the moving speed of the transfer table 490 when a scribe line is formed. The minimum value exists because when the moving speed of the transfer table 490 is excessively low, the amount of heat per unit area supplied to the sheet glass 410 becomes excessive, and the sheet glass is completely divided, This is because a crack that does not occur (for example, a crack extending in a direction other than the desired direction) may occur. On the other hand, the maximum value exists when the moving speed of the transfer table 490 is excessively high, the amount of heat per unit area supplied to the sheet glass 410 is too small, and the stress necessary for the extension of the scribe line is present. This is because it does not occur.

  Further, from the results of Experiments A1 to A5, it is understood that the conditions for forming the scribe line differ depending on the thickness of the plate glass 410. Table 6 and FIG. 17 show the relationship between the thickness of the plate-like glass 410 and the moving speed (minimum value and maximum value) of the transfer table 490 when a scribe line is formed when the laser beam output is 30 to 60 W. Indicates. In addition, the straight line in FIG. 17 shows the moving speed of the conveyance table 490 when a scribe line is formed on the plate-like glass 410 of each thickness.

  As shown in Table 6 and FIG. 17, the maximum value of the moving speed of the transfer table 490 that can form a scribe line does not monotonously increase or monotonously decrease with respect to the thickness of the sheet glass 410. More specifically, in the range where the thickness of the plate glass 410 is 0.4 mm or less, the maximum moving speed of the transfer table 490 capable of forming a scribe line increases as the plate glass 410 becomes thicker. In the range where the thickness of the glass sheet 410 is 0.4 mm or more, the maximum value of the moving speed of the transfer table 490 capable of forming a scribe line decreases as the glass sheet 410 becomes thicker. That is, the maximum value of the moving speed of the transfer table 490 capable of forming a scribe line becomes a peak when the thickness of the plate glass 410 is 0.4 mm, and decreases as the thickness is separated from 0.4 mm.

  This phenomenon is explained as follows. That is, in order to form the scribe line, it is necessary to generate a certain amount of stress in the sheet glass, and for this purpose, the rate of temperature change (° C./mm) between the front and back surfaces of the sheet glass. Need to be high to some extent. Even if the thickness of the glass sheet is changed within a predetermined thickness range and the laser beam is irradiated to the glass sheet of each thickness, the surface temperature and the back surface temperature of the glass sheet of each thickness (That is, there is no significant difference in the temperature difference between the front and back surfaces of each thickness of glass sheet). Therefore, the thicker the plate-like glass, the smaller the temperature change rate (° C./mm) between the front surface and the back surface, and it becomes difficult to form a scribe line. It is considered that this influence appears dominantly in the sheet glass having a thickness range of 0.4 mm or more. On the other hand, in a sheet glass having a predetermined thickness or less, when the surface of the sheet glass is heated with a laser beam, the heat of the surface tends to reach the back surface immediately, and this tendency is such that the sheet glass becomes thinner. Become prominent. That is, the thinner the glass sheet, the smaller the temperature difference between the front surface and the back surface, and the lower the temperature change rate (° C./mm) between the front surface and the back surface, making it difficult to form a scribe line. This influence is considered to be dominant in the sheet glass having a thickness range of 0.4 mm or less.

As shown in Table 6 and FIG. 17, in the sheet glass 410 having a thickness range of less than 0.4 mm, the conveyance when the scribe line 111 is generally formed as the sheet glass 410 becomes thinner. The maximum value of the moving speed of the table 490 decreases. On the other hand, in the float process, the transport speed V _g of the strip glass 110 (that is, the transport direction component V _hx of the moving speed V _h of the head 151) is increased as the strip glass 110 to be formed becomes thinner. Considering these relationships, in the band-like glass 110 having a thickness range of less than 0.4 mm, the upper limit value of the width direction component V _hy of the moving speed V _h of the head 151 when the scribe line 111 is appropriately formed. the ratio of the conveyance speed V _g for _{V hyMAX (V g / V hyMAX} ) and arctangent of the ratio _{(θ = arctan (V g /} V hyMAX)) becomes larger as the ribbon 110 is thinner (see FIG. 18 ). That is, the angle θ based on each upper limit value V _hyMAX of each width direction component V _hy in the case where the scribe line 111 is formed on the strip glass 110 of less than 0.4 mm is assumed to be the thinnest strip that is assumed to be less than 0.4 mm. When the scribe line 111 is formed on the glass 110, the angle θ is equal to or less than the upper limit value V _hyMAX of the width direction component V _hy . Therefore, when the scribe line 111 is formed on the strip glass 110 having a thickness range of less than 0.4 mm in online cutting of the strip glass 110 formed by the float process, the thickness of the strip glass 110 is assumed to be the maximum. If the angle θ is set so small that the width direction component V _hy becomes an upper limit value at a thin value, each width direction component when forming the scribe line 111 on the strip glass 110 having a thickness of less than 0.4 mm. It is _understood that V _hy is surely within the respective upper limit values V _hyMAX . Further, in consideration of FIG. 18, according to the angle θ set in this way (approximately θ1 _MIN or so), the scribe lines are formed on the glass strips 110 of various thicknesses including the glass ribbon 110 having a thickness of 0.4 mm or more. It can be seen that 111 can be reliably formed.

Moreover, as shown in Table 6 and FIG. 17, in the sheet glass 410, generally, as the sheet glass 410 becomes thinner, the minimum value of the moving speed of the transport table 490 when the scribe line 111 is formed. Will increase. On the other hand, in the float process, the conveyance speed V _g of the strip glass 110 is increased as the strip glass 110 to be formed becomes thinner. In view of these relationships, in the glass ribbon 110, the ratio of the conveying speed V _g with respect to the lower limit value V _HyMIN the width direction component V _hy the moving velocity V _h of the head 151 when the scribe lines 111 are properly formed ( V _g / V _hyMIN ) and the arc tangent (θ = arctan (V _g / V _hyMIN )) of this ratio are substantially constant. That is, the angle (θ = arctan (V _g / V _hyMIN )) based on the lower limit value V _hyMIN of the width direction component V _hy when the scribe line 111 is formed on the belt-like glass 110 is the thinnest belt glass assumed. When the scribe line 111 is formed at 110, the angle θ substantially coincides with the lower limit value V _hyMIN of the width direction component V _hy . Therefore, when the scribe line 111 is formed on the strip glass 110 in online cutting of the strip glass 110 formed by the float process, the width direction component V _hy is obtained when the strip glass 110 has the thinnest thickness expected. If the angle θ is set so that becomes the lower limit value, it is understood that each width direction component V _hy when the scribe line 111 is formed on the strip-shaped glass 110 of each thickness is approximately near the lower limit value. Further, if the relationship between the thickness of the strip glass 110 to be formed and the conveyance speed V _g of the strip glass 110 is considered in detail, according to the angle θ thus set (approximately θ1 _MAX ), each width direction It is _understood that the component V _hy is _{equal to} or greater than each lower limit value V _hyMIN and near each lower limit value (see FIG. 18).

Moreover, as shown in Table 6 and FIG. 17, in the plate-like glass 410 having a thickness range of 0.4 mm or more, the thicker the plate-like glass 410 is, the more the scribe line is formed. The maximum value of the moving speed decreases. On the other hand, in the float process, generally, the thicker the strip glass 110 to be formed, the lower the transport speed V _g of the strip glass 110 (that is, the transport direction component V _hx of the moving speed V _h of the head 251). Considering these relationships, in the band-shaped glass 110 having a thickness range of 0.4 mm or more, the upper limit value of the width direction component V _hy of the moving speed V _h of the head 151 when the scribe line 111 is appropriately formed. the ratio of the conveyance speed V _g for _{V hyMAX (V g / V hyMAX} ) is approximately constant even when thick ribbon 110. That is, the angle (θ = arctan (V _g / V _hyMAX )) based on the upper limit value V _hyMAX of the width direction component V _hy when the scribe line 111 is formed on the strip glass 110 _exceeding 0.4 mm is 0.4 mm. When the scribe line 111 is formed on the belt-like glass 110, the angle θ substantially coincides with the upper limit value V _hyMAX of the width direction component V _hy . Therefore, when the scribe line 111 is formed on the strip glass 110 having a thickness range of 0.4 mm or more in online cutting of the strip glass 110 formed by the float process, the width is obtained when the strip glass 110 is 0.4 mm. If the angle θ is set so that the direction component V _hy becomes the upper limit value, each width direction component V _hy when the scribe line 111 is formed on the strip-shaped glass 110 having a thickness of 0.4 mm or more is substantially set to each upper limit value. It is understood that it will be near. Further, if the relationship between the thickness of the strip glass 110 to be formed and the conveyance speed V _g of the strip glass 110 is considered in detail, according to the angle θ thus set (approximately θ2 _MIN ), each width direction It is _understood that the component V _hy is within each upper limit value V _hyMAX and near each upper limit value (see FIG. 18).

  By referring to the reference embodiments A1 and A2 together, the following invention can be derived.

(Reference Invention A1)
Strip glass that is unloaded from the float bath and transported in a predetermined transport direction, where the maximum thickness is assumed to be T _max , the minimum value is T _min , and T _min <0.4 mm <T _max The belt-shaped glass is cut using a crack stretching device that forms a scribe line extending in the width direction perpendicular to the transport direction by supplying laser light and a coolant to the belt-shaped glass while traversing the belt-shaped glass. A method of cutting glass,
When the thickness of the glass strip is less than 0.4 mm, the crack elongating device should move in a first transverse direction, crossing the glass ribbon, and forming an angle θ1 with the width direction. A first transverse direction and a second transverse direction in which the crack stretcher should move when the thickness of the strip glass is 0.4 mm or more, between the strip glass and the width direction A transverse direction setting step for setting a second transverse direction to form an angle θ2 that is less than the angle θ1;
When the thickness of the strip glass is less than 0.4 mm, it moves in the first transverse direction, and when the thickness of the strip glass is 0.4 mm or more, it moves in the second transverse direction. A crack extension step of forming the scribe line by supplying the laser beam and the coolant from the crack extension device to the strip glass;
A glass cutting step for cutting the strip glass along the scribe line, and
The transverse direction setting step includes:
A specific sub-step A1 for specifying an upper limit value V _hy1MAX of the width direction component of the moving speed of the crack extension device capable of forming the scribe line in the strip glass having a thickness of T _min ;
A specific sub-step B1 for specifying a lower limit value V _hy1MIN of the width direction component of the moving speed of the crack extension device capable of forming the scribe line in the strip glass having a thickness of T _min ;
Thickness of the glass ribbon T _min carrying speed V _g1, the upper limit value V _Hy1MAX and the lower limit value _{V hy1MIN, arctan {(V g1} ) / (V hy1MAX)} ≦ θ1 ≦ arctan {(V g1) / (V _hy1MIN )} to determine the angle θ1 so as to satisfy,
determination sub-step C2 for determining the angle θ2 so as to satisfy θ2 <arctan {(V _g1 ) / (V _hy1MAX )}.
A method for cutting strip glass.

(Reference Invention A2)
Strip glass that is unloaded from the float bath and transported in a predetermined transport direction, where the maximum thickness is assumed to be T _max , the minimum value is T _min , and T _min <0.4 mm <T _max The belt-shaped glass is cut using a crack stretching device that forms a scribe line extending in the width direction perpendicular to the transport direction by supplying laser light and a coolant to the belt-shaped glass while traversing the belt-shaped glass. A method of cutting glass,
A transverse direction setting step for setting a transverse direction in which the crack stretching device is to move, which intersects the glass ribbon and forms an angle θ1 with the width direction;
A crack extension step of forming the scribe line by supplying the laser beam and the coolant to the strip glass from the crack extension device moving in the transverse direction;
A glass cutting step for cutting the strip glass along the scribe line, and
The transverse direction setting step includes:
A specific sub-step A1 for specifying an upper limit value V _hy1MAX of the width direction component of the moving speed of the crack extension device capable of forming the scribe line in the strip glass having a thickness of T _min ;
A specific sub-step B1 for specifying a lower limit value V _hy1MIN of the width direction component of the moving speed of the crack extension device capable of forming the scribe line in the strip glass having a thickness of T _min ;
Thickness of the glass ribbon T _min carrying speed V _g1, the upper limit value V _Hy1MAX and the lower limit value _{V hy1MIN, arctan {(V g1} ) / (V hy1MAX)} ≦ θ1 ≦ arctan {(V g1) / (V _hy1MIN )}, and a determination sub-step C1 for determining the angle θ1.
A method for cutting strip glass.

(Reference Invention A3)
In addition to the reference invention A1 or A2, the decision sub-step C1 _satisfies arctan {(V _g1 ) / (V _hy1MAX )} ≦ θ1 ≦ arctan {(V _g1 ) / (V _hy1MAX × 0.6)}. The method for cutting the strip glass to determine the angle θ1.

(Reference Invention A4)
In addition to any one of the reference inventions A1 to A3, the laser beam is irradiated to the plate glass while moving the laser beam relative to the plate glass having a thickness of T _{min at} a relative speed V _R1. Te, in an off-line experiment of forming a scribe line on the plate-like glass, by measuring the upper limit value of the scribe line can be formed relative velocity V _R1, the cutting process of the glass ribbon to implement the specific sub-step A1.

(Reference Invention A5)
In addition to any one of the reference inventions A1 to A4, the output of the laser light irradiated in the crack extension step is a method for cutting a strip glass that is 30 W or more and 60 W or less.

(Reference Invention A6)
In addition to any one of the reference inventions A1 to A5, in the crack extension step, the length of the irradiated region that is the region irradiated with the laser light in the strip glass is 15 mm or more and 30 mm or less, and the irradiated region The method for cutting the strip glass in which the laser beam is irradiated so that the width of the glass is 0.1 mm or more and 3.0 mm or less.

(Reference Invention A7)
In addition to any one of the reference inventions A1 to A6, T _min is 0.28 mm and T _max is 1.1 mm.

(Reference Invention A8)
In addition to any one of the reference inventions A1 to A7, the strip glass is a soda-lime glass cutting method.

(Reference Invention A9)
In addition to Reference Invention A8, indicated by mass%, the band glass is
SiO ₂ : 65-80%
Al ₂ O ₃ : 0 to 5%
MgO: 1-10%
CaO: 5 to 15%
Na ₂ O: 10 to 18%
K ₂ O: 0 to 5%
B ₂ O _3: 0~5%
MgO + CaO: 6-15%
Na ₂ O + K ₂ O: 10 to 20%
The cutting method of the strip glass which has the component of.

(Reference Embodiment B1)
In the linear slide member of Patent Document X, the moving speed of the head is set together with the conveying speed of the belt-shaped glass and the moving direction of the head so that the scribe line extends in the width direction of the belt-shaped glass.

  By the way, the outer peripheral wall of the injection nozzle for injecting the refrigerant has a predetermined thickness. For this reason, if the coolant is injected with the opening of the injection nozzle directed in the direction perpendicular to the surface of the strip glass, the cooled region is separated from the irradiated region by this thickness, and sufficient tensile stress is generated in the strip glass. Therefore, it may be difficult to form a scribe line. In consideration of this point, the refrigerant is jetted in a direction inclined from the thickness direction of the strip glass.

  When the position in the thickness direction of the strip glass changes due to the vibration of the strip glass, the scribe line may not be formed.

According to the study by the present inventors, there is a range suitable for forming a scribe line in the width direction component of the strip glass at the moving speed of the head (that is, the relative speed V _R between the strip glass and the head). The present inventors considered that a scribe line can be formed more reliably by paying attention to this point.

  Hereinafter, Reference Embodiment B1 will be described with reference to the drawings. In the following description, the same member is denoted by the same reference numeral in each drawing, and the description may be omitted.

  FIG. 19 shows a state in which a strip glass (glass ribbon) 510 carried out from a glass forming apparatus and conveyed along a reference conveyance surface which is a horizontal surface is observed from above. The band-shaped glass 510 is formed to a predetermined thickness in a glass forming apparatus (for example, a float bath) installed on the upstream side in the transport direction 540 (upstream side of the region shown in FIG. 19), and constant in the transport direction 540. Transported at speed. The range of the thickness of the belt-like glass 510 that is the subject of the present embodiment is not particularly limited as long as a scribe line can be formed by laser light, but is, for example, 0.1 to 5 mm.

  The belt-shaped glass 510 is transported by a transport device. Examples of the transport device include a transport roller and a transport belt. In this embodiment, the conveyance device is a conveyance roller 521 that supports the belt-like glass 510 from below, and a conveyance surface constituted by the conveyance rollers 521 is referred to as a reference conveyance surface. In the present embodiment, the maximum value of the absolute value of the fluctuation amount in the thickness direction of the belt-shaped glass assumed when the reference transport surface is used as a reference is described as a width W. The width W is a value that depends on vibration, deflection, and the like of the strip glass 510 (see FIG. 20). When the thickness of the belt-like glass 510 is 0.1 to 5 mm and the transport roller 521 is used as the transport device, the width W (absolute value) is, for example, 10 mm. In addition, when the strip | belt-shaped glass 510 is thin, it is preferable to make the pitch of the conveyance roller 521 fine.

  A scribe line 511 is formed on the belt-like glass 510 by a scribe line forming head (hereinafter simply referred to as “head”) 551 traversing the glass strip 510 (scribe line forming step). The scribe line 511 is formed so as to extend in parallel with the width direction 541 of the belt-like glass 510 orthogonal to the transport direction 540 and to maintain a predetermined interval in the transport direction 540. The band-shaped glass 510 is divided at the scribe line 511 by a cutting device (moving roller 525) disposed on the downstream side in the transport direction 540 to become a glass plate 600 (glass cutting step).

  In order to form a scribe line 511 parallel to the width direction 541 of the belt-like glass 510, the head 551 runs obliquely with respect to the width direction 541. The oblique traveling direction 542 and the width direction 541 of the head 551 form an angle θ that is determined depending on the conveyance speed of the belt-like glass 510 and the traveling speed of the head 551. The head 551 travels at a constant speed by being guided by a guide (not shown) that crosses the upper side of the belt-like glass 510 in parallel with the oblique traveling direction 542. For convenience, a line on which the head 551 travels is shown as a head travel line 550 in FIG. The head 551 and the guide constitute a crack extension device.

  A sectional view of FIG. 19 along the head travel line 550 is shown in FIG. 21, and a partially enlarged view of FIG. 21 is shown in FIG. The head 551 includes an optical system 570 for condensing the laser light on the belt-like glass 510 and an injection nozzle 580 for jetting a coolant to locally cool the belt-like glass 510. A state in which the laser beam and the coolant are supplied to the belt-like glass 510 is shown in FIG. The head 551 further includes a cutter 519 that is a crack forming device that forms an initial crack in the belt-like glass 510.

  The cutter 519 is typically a wheel cutter, but there is no particular limitation on the type of the cutter 519 as long as a stretchable crack can be formed in the belt-like glass 510. The cutter 519 plays a role of forming an initial crack, which is a starting point of the scribe line 511, in the belt-like glass 510. The initial crack is formed at or near the end of the strip glass 510 (in the case of the strip glass 510 shown in FIG. 19, the right end in the figure).

  Extension of the initial crack for forming the scribe line 511 is performed by the laser beam 517 and the refrigerant 518 supplied from the head 551. In other words, if heating by the laser beam 517 and rapid cooling by the refrigerant 518 are applied successively at the end of the crack, a tensile stress is generated on the glass surface 510f in the vicinity of the crack, and the crack extends due to this tensile stress. The head 551 advances on the head travel line 550 (to the left in the illustrated form) while extending the crack. In the present embodiment, a crack that is formed by extending an initial crack and that can cut the glass strip 510 along the crack in the glass cutting step is referred to as a scribe line 511.

  As shown in FIG. 24, as the head 551 travels, the belt-like glass 510 is irradiated with the laser beam 517 via the optical system 570, and the coolant 518 is supplied from the injection nozzle 580. The region 528 proceeds on the head travel line 550 in this order. In other words, the region to be cooled 528 follows the irradiated region 527, and these regions travel on the head travel line 550. The head 551 maintains the relative positional relationship between the laser beam condensing device (optical system 570) that forms the irradiated region 527 and the cooling device (jet nozzle 580) that forms the cooled region 528. The role to move is left.

Returning to FIG. 22, the laser light irradiation system and the refrigerant supply system will be briefly described. However, these systems can be used without any particular limitation. The laser beam 517 is condensed from the laser beam generator 571 to the irradiated region 527 of the belt-like glass 510 via the laser beam expanding device 572 and the condensing device (optical system 570) in the head 551. The optical system 570 includes mirrors and other optical elements 573, 574, and 575. As the laser beam 517, a CO ₂ laser, a YAG laser, or the like can be used. The refrigerant 518 is supplied from a refrigerant supply device (not shown) to the area to be cooled 528 via an injection nozzle 580 provided in the head 551. For example, air, nitrogen, helium, or water may be used as the refrigerant.

  As shown in FIG. 25, the optical elements 573, 574, and 575 are configured such that the laser beam 517 forms a beam waist 517w on the traveling direction side of the laser beam 517 relative to the optical elements 573, 574, and 575. (Note that FIG. 25 shows the optical path of the laser beam 517 when no member is disposed on the traveling direction side of the laser beam 517 relative to the optical elements 573, 574, and 575). In the present embodiment, the laser beam 517w is set so that the beam waist 517w of the laser beam 517 is set at a reference position 562 that is separated from the transport device (transport roller 521) by the thickness t of the belt-like glass 510 on the side opposite the transport device 561. Irradiate light (see FIG. 23). In the present embodiment, an angle φ is formed between the extending direction of the injection nozzle 580 (the opening direction for injecting the refrigerant) and the direction perpendicular to the reference transport surface 561. Accordingly, the coolant 518 can be injected from the upstream side in the width direction 541 to the cooled region 528 along the direction inclined with respect to the thickness direction of the strip glass 510, and the cooled region 528 is separated from the irradiated region 527. Can be prevented. The angle φ is, for example, 0 to 60 °.

  The output of the laser beam is not particularly limited, but is typically 30 W or more and 100 W or less. When the output of the laser beam is excessively large, the strip glass 510 may be completely divided or an unintended crack (for example, a crack extending in a direction other than a desired direction) may occur. On the other hand, if it is too small, it is difficult to extend the initial crack.

  The length of the irradiated region 527 is, for example, not less than 10 mm and not more than 200 mm, and for example, not less than 10 mm and not more than 100 mm. Further, the width of the irradiated region 527 is, for example, not less than 0.1 mm and not more than 3 mm.

  The band-like glass 510 on which the scribe line 511 is formed is divided along the scribe line 511 on the downstream side in the transport direction 540. As shown in FIGS. 26A and 26B, when the scribe line 511 of the belt-like glass 510 approaches, the moving roller 525 lifts the belt-like glass 510 in the thickness direction. Cracks constituting the scribe line 511 extend due to the stress generated by the weight of the raised glass strip 510, and the glass strip 510 is broken. More specifically, the moving roller 525, which is a glass cutting device, lifts the belt-like glass 510 so that the displacement amount of the portion in contact with the moving roller 525 is maximized, and advances the cutting along the scribe line 511. As shown in FIG. 26C, after the division is completed, the moving roller 525 is pulled down to prepare for the next division.

  The moving roller 525 supports the belt-like glass 510 while supporting the back surface thereof on both the upstream side (the left side in the figure) and the downstream side (the right side in the figure) across the scribe line 511 so that stress is applied to the scribe line 511. (Fig. 26 (b)). As the moving roller 525 subsequently descends, the downstream end 510e of the strip glass 510 once moved upward returns to the lower side (FIG. 26 (c)).

  In this embodiment, the cutting at the scribe line 511 is caused to proceed by the stress generated by its own weight. However, when the moving roller 525 is raised, the strip glass 510 is moved upstream or downstream in the conveying direction 540 of the moving roller 525. The cutting may be advanced by pressing the surface 510f from above. In this way, even when the thin and light strip glass 510 is divided, it is easy to ensure the stress required for the division.

In the scribe line forming step of the present embodiment, the irradiated region 527 irradiated with the laser beam 517 and the cooled region 528 injected with the coolant 518 are set on the surface 510f of the belt-like glass 510, and the cooled region 528 is The irradiated region 527 and the cooled region 528 are moved relative to the belt-like glass 510 in a predetermined direction (width direction 541) at a relative speed V _R so as to follow the irradiated region 527, to the cooled region 528. The scribe line 511 is formed by extending the initial crack. Then, in the glass cutting step, the strip glass 510 is cut along the scribe line 511. In the present embodiment, the relative speed V _R is set in a relative speed setting step that is performed before the scribe line forming step. Hereinafter, the relative speed setting step will be specifically described.

  The relative speed setting step includes a first specific substep, a second specific substep, and a determination substep. In this embodiment, these substeps are performed in this order. However, the first specific substep may be performed after the second specific substep.

In the first specific sub-step, when the strip glass 510 is transported in a state where the back surface 510b of the strip glass 510 is in contact with the reference transport surface 561, the irradiated region 527 and the strip glass 510 that can form the scribe line 511 The lower limit value V ₁ of the relative speed is specified. First specific sub-step, for example, while setting the beam waist of the laser beam on the position of the surface of the plate-like glass, while relatively moving at a relative speed V _RP said laser beam to said plate glass and irradiating the laser beam on the surface of the plate-like glass, in an off-line experiment of forming a scribe line on the plate-like glass, was performed by measuring the lower limit of formable relative velocity V _RP said scribe line May be.

In the second specific sub-step, the scribe line 511 can be formed when the back surface 510b of the belt-like glass 510 changes in the width W in the thickness direction from the back surface 510b of the belt-like glass 510 to the front surface 510f when viewed from the reference transport surface 561. The upper limit value V ₂ of the relative speed between the irradiation region 527 and the strip glass 510 is specified. The second specific sub-step is, for example, in a state where the beam waist is set at a position where the width W is moved in the thickness direction of the sheet glass from the surface of the sheet glass toward the back surface as viewed from the position of the surface of the sheet glass. offline experiments while relatively moving at a relative speed V _RP of the laser beam relative to the plate-like glass is irradiated with the laser beam on the surface of the plate-like glass, forming a scribe line on the plate-like glass in may be performed by measuring the upper limit of formable relative velocity V _RP the scribe line.

In the determination substep, the relative speed V _R is determined so as to satisfy V ₁ ≦ V _R ≦ V ₂ .

As understood by consideration of the later, in order to enable a scribe line 511 to the ribbon 510, the relative speed V _R, it is necessary to set within a predetermined range. This predetermined range shifts to a lower side as the surface 510f of the glass strip 510 moves away from the reference position 562 due to vibration or the like. More specifically, this predetermined range is more when the front surface 510f of the belt-like glass 510 changes in the direction from the back surface 510b to the front surface 510f than when it changes in the direction from the front surface 510f to the back surface 510b. There is a tendency to shift to a significantly lower side. In the present embodiment, in consideration of this tendency, the scribe line 511 can be formed even when the front surface 510f of the belt-like glass 510 changes in the width W in the direction from the back surface 510b to the front surface 510f when viewed from the reference position 562. In addition, the upper limit of the range of the relative speed V _R is set to V ₂ . Thus, if the position change is within the width W from the reference position 562 of the surface 510f of the ribbon 510, be varied in any direction in the thickness direction of the ribbon 510, the relative speed V _R is too fast A situation in which the scribe line 511 is not formed can be avoided. Further, the lower limit of the range of the relative speed V _R is set to V ₁ so that the scribe line 511 can be formed even when the surface 510 f of the belt-like glass 510 exists at the reference position 562. Thus, in the case the position change from the reference position 562 of the surface 510f of the ribbon 510 is within a width W, it can avoid a situation where scribe lines 511 relative velocity V _R is too late can not be formed. That is, according to the present embodiment, the scribe line 511 can be reliably formed when the position fluctuation of the surface 510f of the belt-like glass 510 from the reference position 562 is within the width W.

Note that the lower limit of the range of the relative speed V _R is set to a value larger than V _1, which is the minimum value of the relative speed for forming the scribe line 511 when the surface 510f of the strip glass 510 exists at the reference position 562, for example, It may be set to (V ₁ + V ₂ ) / 2. If the relative speed V _R is set in this way, the angle θ formed between the oblique traveling direction 542 and the width direction 541 can be set to a relatively small value, so that the degree of freedom in designing the cutting device is improved. .

  Further, before the relative speed setting step, the maximum value of the absolute value of the amount of variation in the thickness direction of the strip glass 510 when the strip glass 510 is transported by the transport device is measured, and the width W is set as the maximum value. A fluctuation amount evaluation step may be performed. If the variation amount evaluation step is performed, the width W can be accurately specified. However, as the width W, a value determined based on the specifications of the transfer device or the like may be employed, or a value determined by an empirical rule may be employed.

(Reference embodiment B2)
Each member in the reference embodiment B2 has already been described above with reference to FIG.

In the reference embodiment B2, the relative speed setting step is omitted. However, in the reference embodiment B2, the beam waist 517w of the laser beam 517 is from the back surface 510b of the strip glass 510 with respect to the reference position 562 that is separated from the transport device by the thickness t of the strip glass as viewed from the reference transport surface 561. The laser beam 517 is irradiated so as to be separated in the direction toward the surface 510f (that is, on the side opposite to the conveying device) (see FIG. 27). As will be understood from the following discussion, the range of the relative speed V _R at which the scribe line 511 can be formed on the belt-like glass 510 is when the surface 510f of the belt-like glass 510 changes in the direction from the back surface 510b toward the surface 510f. Compared with the case where the surface changes from the front surface 510f toward the back surface 510b, the surface shifts to a significantly lower side (that is, when the surface 510f of the belt-like glass 510 changes from the back surface 510b toward the surface 510f, The range of the relative speed V _R at which the scribe line 511 can be formed on the belt-like glass 510 is shifted asymmetrically when it fluctuates in the direction from 510f toward the back surface 510b). If the laser beam 517 is irradiated with respect to the reference position 562 so that the beam waist 517w of the laser beam 517 is separated from the back surface 510b of the belt-like glass 510 toward the front surface 510f as in the present embodiment, the above asymmetry is achieved. As a result, a situation in which the scribe line 511 is not formed is less likely to occur.

  The interval between the beam waist 517w of the laser beam 517 and the reference position 562 is less likely to occur when the front surface 510f of the belt-like glass 510 changes in the direction from the back surface 510b to the front surface 510f, and the scribe line 511 is not formed. It is preferable to set so that the risk that the scribe line 511 is not formed is not excessively increased when the band-like glass 510 changes in the direction from the front surface 510f toward the back surface 510b. For example, the distance between the beam waist 517w of the laser beam 517 and the reference position 562 may be greater than 0 mm and not greater than 5 mm, and may be, for example, not less than 0.5 mm and not greater than 4 mm.

In the reference embodiment B2, the relative speed setting step is omitted, but the relative speed setting step may be performed. In this case, when it is assumed that the beam waist is set at the reference position 562 in the first specific sub-step, the strip-shaped glass 510 is transported with the back surface 510b of the strip-shaped glass 510 in contact with the reference transport surface 561. When the lower limit V ₁ of the relative velocity between the irradiated region 527 capable of forming the scribe line 511 and the belt-like glass 510 is specified, and it is assumed that the beam waist is set at the reference position 562 in the second specifying substep. Furthermore, when the back surface 510b of the belt-like glass 510 changes in the width W in the thickness direction from the back surface 510b of the belt-like glass 510 toward the front surface 510f when viewed from the reference transport surface 561, the irradiated region 527 capable of forming the scribe line 511 and the belt-like shape. What is necessary is just to identify the upper limit V ₂ of the relative speed with the glass 510.

Hereinafter, the position in the thickness direction of the ribbon 510, the off-line experiments conducted to confirm the relationship between the upper limit and the lower limit of the relative speed V _R, will be described with reference to FIG. 28.

(Experiment B1)
As the plate glass 810, a soda lime glass plate having a thickness of 0.33 mm, a short side length of 100 mm, and a long side length of 200 mm, expressed in mass% and having the following components was prepared.

SiO ₂ : 71.9%
Al ₂ O ₃ : 1.7%
MgO: 4.0%
CaO: 8.0%
Na ₂ O: 13.5%
K ₂ O: 0.9%

  The plate glass 810 was fixed to the transfer table 890 so that the direction along the long side of the plate glass 810 coincided with the transfer direction 842 of the transfer table 890.

  An initial crack 861 was formed in the sheet glass 810 while the transfer table 890 was stationary. Specifically, an initial crack 861 having a length of 10 mm extending from the one point on one short side 810a of the plate glass 810 to the short side 810b was formed. The initial crack 861 was formed using a sintered diamond cutter wheel (outer diameter φ2.5 mm, thickness 1.0 mm, inner diameter φ1.1 mm, blade edge angle 135 degrees).

Next, while moving the transfer table 890, the surface of the plate glass 810 was irradiated with laser light 817 and water (refrigerant) 818 was jetted. Specifically, first, the irradiated region 827 and the cooled region 828 are initially set at positions ahead of the short side 810a in the transport direction 842, and the major axis of the initial crack 861 and the major axis of the irradiated region 827 are equal. Then, the position of the transfer table 890 was initially set so that the distance Δx between the two long axes was 0 μm. Next, the irradiated region 827 has a length of 24 mm and a width of 1 mm, a beam waist 817 w of the laser light 817 is formed on the surface of the plate glass 810, and the cooled region 828 is the irradiated region 827. The laser beam condensing device and the cooling device were adjusted so as to be in contact with one end in the length direction (FIG. 28A). Next, while maintaining the positions of the irradiated region 827 and the cooled region 828 fixed, the transport table 890 is moved to 384 mm / second in the transport direction 842 until these positions are downstream of the short side 810b in the transport direction 842. It was moved at a speed of s (relative speed V _RP ) (FIGS. _{28B and 28C} ). The depth of the scribe line (crack 862) formed at this time was examined.

Specifically, a 60 W laser beam outputted from a CO ₂ laser oscillator (ULC-100 manufactured by UNIVERSAL LASER SYSTEMS) is refracted and reflected using two axicon lenses, a cylindrical lens (depth of focus F = 5 mm) and a mirror. The irradiated region 827 was set by reflection (hereinafter, a CO ₂ laser oscillator, two axicon lenses, a cylindrical lens, and a mirror may be collectively referred to as an optical system). Moreover, the to-be-cooled area | region 828 was set by injecting the water of the injection amount 5.0 ml / min from a nozzle (Everloy minimist 04-10-13). The nozzles were installed so as to open in a direction inclined by φ = 20 ° in the direction from the upstream side to the downstream side in the conveyance direction 842 when viewed from the direction perpendicular to the main surface of the conveyance table 890. Further, the nozzles were arranged so that a gap of 10.5 mm was formed between the main surface of the transfer table 890.

  Next, the moving speed of the transfer table 890 was sequentially changed, and the same experiment was repeated. The same experiment was performed by sequentially moving the optical system and the nozzle in a direction perpendicular to the main surface of the transfer table 890 (by sequentially changing the height of the optical system and the nozzle). The results are shown in Table 7. In Table 7, a height of 0 mm indicates a state in which a space of 10.5 mm is formed between the main surface of the transfer table 890 and the nozzle, and a height of positive indicates that the optical system and A state in which the nozzle is moving away from the sheet glass 810 and a negative height indicates a state in which the optical system and the nozzle are approaching the sheet glass 810. The numerical values other than the moving speed and the height in Table 7 indicate the depth (μm) of the crack (vertical crack) 862 constituting the formed scribe line (for example, Table 7 shows the transfer table 890). This indicates that a scribe line having a depth of 120 μm was formed when the moving speed was 192 mm / s and the height was −3.8 mm). It should be noted that the parentheses attached to the numerical values indicate that although a crack having a predetermined depth was formed, it was impossible to divide the sheet glass 810 along the formed crack (that is, formation) The cracks made are not scribe lines sufficient to perform the cutting step as specified in the present invention). N indicates that the initial crack 861 did not expand at all. F indicates that the glass sheet 810 is completely divided.

  The result of Experiment B1 is a transfer table 890 in the case where a scribe line (a crack formed by extending the initial crack 861 that can sever the glass sheet 810 along itself, hereinafter the same) is formed. It can be seen that there is a minimum value and a maximum value in the moving speed of. The minimum value exists because when the moving speed of the transfer table 890 is excessively low, the amount of heat per unit area supplied to the plate glass 810 becomes excessive, and the plate glass 810 is completely divided, This is because unintended cracks (for example, horizontal cracks) may occur. On the other hand, the maximum value exists when the moving speed of the transfer table 890 is excessively high, the amount of heat per unit area supplied to the sheet glass 810 becomes too small, and the stress necessary for the extension of the scribe line is present. This is because it does not occur. In Table 7, the reason why the sheet glass 810 could not be divided in the cases where the numerical values are parenthesized is not clear, but the amount of heat per unit area supplied to the sheet glass 810 becomes excessive, and the refrigerant 818 As a result of the elongation of the crack before reaching, there is a possibility that the smoothness of the cross section of the crack becomes insufficient, or the elongation direction of the crack is slightly deviated from the predetermined direction.

  Further, from the result of Experiment B1, it is understood that the conditions for forming the scribe line differ depending on the height of the optical system and the nozzle. Table 8 and FIG. 29 show the relationship between the height of the optical system and the nozzle and the moving speed (minimum value and maximum value) of the transfer table 890 when a scribe line is formed.

  As shown in Table 8 and FIG. 29, the minimum value and the maximum value of the moving speed of the transfer table 890 that can form a scribe line tend to decrease as the height of the optical system and the nozzle moves away from 0 mm. This is because in Experiment B1, when the height is 0 mm, the laser beam is irradiated so that the beam waist 817w of the laser beam 817 is formed on the surface of the plate glass 810.

  More specifically, when the height is reduced from 0 mm, the reduction rate of the minimum value and the maximum value is larger than when the height is increased from 0 mm. This phenomenon is explained as follows. That is, when the height of the optical system and the nozzle is 0 mm, the cooling region 828 is in contact with one end in the length direction of the irradiated region 827 (FIG. 30). On the other hand, when it becomes high from 0 mm, the overlapping area | region 829 where the to-be-cooled area | region 828 and the to-be-irradiated area | region 827 overlapped will arise (FIG. 31). When the overlapping region 829 occurs, the amount of heat that the laser beam 817 gives to the plate glass 810 decreases, so that the stress generated in the plate glass 810 decreases and it becomes difficult to form a scribe line. On the other hand, when it is lowered from 0 mm, a gap 830 is generated between the cooled region 828 and the irradiated region 827 (FIG. 32). When the gap 830 is generated, a time blank is generated between the time when the plate glass 810 is heated by the laser light 817 and until it is cooled by the refrigerant 818. Therefore, the stress generated in the plate glass 810 is reduced, and the scribe is performed. Lines are difficult to form. When the gap 830 is generated, the amount of decrease in stress is larger than when the overlap region 829 is generated. Therefore, when the height is reduced from 0 mm, the minimum value and the maximum value are increased as compared with the case where the height is increased from 0 mm. It is thought that the rate of decrease in the value has increased.

From the results shown in Table 8 and FIG. 29, when the belt-like glass 510 being conveyed fluctuates toward the front surface 510f to which the laser beam 517 and the refrigerant 518 are supplied, the scribe line 511 is more than when fluctuated toward the back surface 510b. It can be said that the situation where no is formed is likely to occur. Considering this, when the beam waist 517w of the laser beam 517 is set slightly on the irradiation side of the laser beam 517 from the reference position 562, the band-shaped glass 510 changes to the front surface 510f side and the back surface 510b side. As a result, it can be said that it is difficult to invite a situation in which the scribe line 511 is not formed. Further, by setting the relative speed V _R in accordance with the case where the maximum amount of variation ribbon 510 is assumed on the surface 510f side, even if the same level fluctuation on the back surface 510b side, avoid a situation in which the scribe lines 511 are not formed I can say that.

  By referring to the reference embodiments B1 and B2 together, the following invention can be derived.

(Reference Invention B1)
In the state where the absolute value of the amount of variation in the thickness direction of the strip glass when the strip glass unloaded from the forming device is based on the reference transport surface determined by the transport device is equal to or less than the width W, It is a cutting method of a strip-shaped glass, which is cut while being transported in the direction along the transport device,
On the surface of the belt-shaped glass, an irradiated region to be irradiated with laser light and a cooled region to which a coolant is jetted are set, and the irradiated region and the irradiated region so that the cooled region follows the irradiated region A scribe line forming step for forming a scribe line by extending an initial crack to the cooled region while moving the cooled region relative to the belt-shaped glass in a predetermined direction at a relative speed V _R ;
A glass cutting step for cutting the strip glass along the scribe line;
A relative speed setting step for setting a relative speed V _R before the scribe line forming step;
In the scribe line forming step, I) the laser beam so that a beam waist of the laser beam is set at a reference position separated from the reference conveying surface by a thickness t of the strip glass on the side opposite to the conveying device. II) Injecting the refrigerant along a direction inclined with respect to the thickness direction from the upstream side in the predetermined direction to the cooled region,
The relative speed setting step includes:
A lower limit value V _{1 of} a relative speed between the irradiated region and the belt-shaped glass where the scribe line can be formed when the belt-shaped glass is transported in a state where the back surface of the belt-shaped glass is in contact with the reference transport surface. A first identification sub-step for identifying
When the back surface of the belt-shaped glass has a width W variation in the thickness direction from the back surface of the belt-shaped glass toward the surface as viewed from the reference transport surface, the irradiated region that can form the scribe line and the belt-shaped glass A second specifying sub-step for specifying an upper limit value V ₂ of the relative speed;
A determination substep for determining a relative speed V _R so as to satisfy V ₁ ≦ V _R ≦ V ₂ .
A method for cutting strip glass.

(Reference Invention B2)
In addition to the reference invention B1, in the determining sub-step, the method for cutting the strip glass, wherein the relative speed V _R is determined so as to satisfy (V ₁ + V ₂ ) / 2 ≦ V _R ≦ V ₂ .

(Reference Invention B3)
In addition to the reference invention B1 or B2, before the relative speed setting step, when transporting the strip glass by the transport device, the maximum value of the absolute value of the variation amount in the thickness direction of the strip glass, A strip glass cutting method comprising a fluctuation amount evaluating step in which the width W is the maximum value.

(Reference Invention B4)
In addition to any one of the reference inventions B1 to B3, in the scribe line forming step, a method for cutting the strip glass in which the length of the irradiated region is 10 mm or more and 200 mm or less.

(Reference Invention B5)
In the state where the absolute value of the amount of variation in the thickness direction of the strip glass when the strip glass unloaded from the forming device is based on the reference transport surface determined by the transport device is equal to or less than the width W, It is a cutting method of a strip-shaped glass, which is cut while being transported in the direction along the transport device,
On the surface of the belt-shaped glass, an irradiated region to be irradiated with laser light and a cooled region to which a coolant is jetted are set, and the irradiated region and the irradiated region so that the cooled region follows the irradiated region A scribe line forming step for forming a scribe line by extending an initial crack to the cooled region while moving the cooled region relative to the belt-shaped glass in a predetermined direction at a relative speed V _R ;
A glass cutting step for cutting the strip glass along the scribe line;
A relative speed setting step for setting a relative speed V _R before the scribe line forming step;
In the scribe line forming step, I) a beam waist of the laser beam from the back surface of the belt-shaped glass with respect to a reference position separated from the transport device by the thickness t of the belt-shaped glass as viewed from the reference transport surface. Irradiating the laser beam so as to be separated in a direction toward the surface, and II) jetting the refrigerant along a direction inclined with respect to the thickness direction from the upstream side in the predetermined direction to the cooled region,
The relative speed setting step includes:
Assuming that the beam waist is set at the reference position, the scribe line can be formed when the strip glass is transported in a state where the back surface of the strip glass is in contact with the reference transport surface. A first specifying substep for specifying a lower limit value V ₁ of a relative speed between the irradiated region and the belt-like glass;
Assuming that the beam waist is set at the reference position, when the back surface of the strip glass has a width W variation in the thickness direction from the back surface of the strip glass toward the surface when viewed from the reference transport surface, A second specifying sub-step for specifying an upper limit value V ₂ of a relative speed between the irradiated region capable of forming a scribe line and the strip glass;
A determination substep for determining a relative speed V _R so as to satisfy V ₁ ≦ V _R ≦ V ₂ .
A method for cutting strip glass.

(Reference Invention B6)
In addition to the reference invention B5, in the determination sub-step, the method for cutting the strip glass, wherein the relative speed V _R is determined so as to satisfy (V ₁ + V ₂ ) / 2 ≦ V _R ≦ V ₂ .

(Reference Invention B7)
In addition to the reference invention B5 or B6, before the relative speed setting step, the maximum value of the absolute value of the variation amount in the thickness direction of the strip glass when the strip glass is transported by the transport device, A strip glass cutting method comprising a fluctuation amount evaluating step in which the width W is the maximum value.

(Reference Invention B8)
In addition to any one of the reference inventions B5 to B7, in the scribe line forming step, a method for cutting a strip-shaped glass in which an interval between the beam waist of the laser beam and the reference position is larger than 0 mm and not larger than 5 mm.

(Reference Invention B9)
In addition to any one of the reference inventions B5 to B8, in the scribe line forming step, a method for cutting the strip glass in which the length of the irradiated region is 10 mm or more and 200 mm or less.

(Reference Invention B10)
A strip glass cutting method for cutting the strip glass carried out of the molding apparatus while transporting the strip glass using the transport device along a reference transport surface determined by the transport device,
On the surface of the belt-shaped glass, an irradiated region to be irradiated with laser light and a cooled region to which a coolant is jetted are set, and the irradiated region and the irradiated region so that the cooled region follows the irradiated region A scribe line forming step for forming a scribe line by extending an initial crack to the cooled region while moving the cooled region relative to the strip glass in a predetermined direction;
A glass cutting step for cutting the strip glass along the scribe line, and
In the scribe line forming step, I) a beam waist of the laser beam from the back surface of the belt-shaped glass with respect to a reference position separated from the transport device by the thickness t of the belt-shaped glass as viewed from the reference transport surface. The laser beam is irradiated so as to be separated in a direction toward the surface, and II) the refrigerant along a direction inclined with respect to the thickness direction of the strip glass from the upstream side in the predetermined direction to the cooled region. Inject,
A method for cutting strip glass.

(Reference Invention B11)
In addition to the reference invention B10, in the scribe line forming step, a method for cutting a strip glass in which an interval between the beam waist of the laser beam and the reference position is greater than 0 mm and not greater than 5 mm.

(Reference Invention B12)
In addition to the reference invention B10 or B11, in the scribe line forming step, the length of the irradiated region is 10 mm or more and 200 mm or less.

(Reference Embodiment C1)

  By the way, when cutting using laser light is applied to online cutting, the depth of the scribe line may not be constant, and the smoothness of the cut surface may be deteriorated, or the formation of the scribe line may be interrupted in the middle. . In online cutting, the strip glass vibrates as it is conveyed, so that the position in the thickness direction of the strip glass deviates from the position where it can be efficiently heated by the laser beam at the scribe position, and a sufficient amount of heat is given to the strip glass. It is because it becomes impossible. Cutting failure due to lack of heat can occur even when a cutting method is adopted in which the mechanical stress is not applied by forming the scribe line deep in the thickness direction of the glass.

  Various studies have been made on laser light suitable for off-line cutting of glass. However, a laser beam suitable for on-line cutting of glass strip has not been sufficiently studied. The present inventors examined an energy density profile of laser light suitable for on-line cutting of strip glass. According to the study by the present inventors, when laser light having a steep energy density profile is applied to on-line cutting of a glass ribbon, the depth of the scribe line is not constant, and the smoothness of the cut surface is deteriorated, or the scribe line is deteriorated. The problem that the formation of the line is interrupted becomes apparent. The details of this reason need to wait for future analysis, but the laser beam having a steep energy density profile due to the difference in the amount of heat given to each part of the glass ribbon due to vibration of the glass ribbon as it is conveyed It is thought that it is expanding due to the adoption of light. In the off-line cutting of glass, the glass does not vibrate, so the problems associated with the use of laser light having a steep energy density profile are small. That is, the present invention solves the above-mentioned problems unique to online disconnection.

  Hereinafter, reference embodiment C1 will be described with reference to the drawings. In the following description, the same member is denoted by the same reference numeral in each drawing, and the description may be omitted.

  FIG. 33 shows a state in which a strip-shaped glass (glass ribbon) 910 that is unloaded from the glass forming apparatus and is transported along a reference transport surface that is a horizontal surface is observed from above. The band-shaped glass 910 is formed to a predetermined thickness in a glass forming apparatus (for example, a float bath) installed on the upstream side in the transport direction 940 (upstream side of the region shown in FIG. 33), and constant in the transport direction 940. Transported at speed.

  The strip glass 910 is transported by a transport roller 921 that supports the strip glass 910 from below. In the present embodiment, a conveyance surface constituted by the conveyance rollers 921 is referred to as a reference conveyance surface. Note that when the belt-like glass 910 is thin, it is preferable to make the pitch of the transport rollers 921 fine. Further, a conveyance belt may be used instead of the conveyance roller 921.

  A scribe line 911 is formed on the band-shaped glass 910 by a scribe line forming head (hereinafter simply referred to as “head”) 951 traversing the glass strip 910 (scribe line forming step). The scribe line 911 is formed along a transverse line extending in the transverse direction across the strip glass 910. The scribe line 911 is formed so as to extend in parallel to the width direction 941 of the strip glass 910 orthogonal to the transport direction 940 and to maintain a predetermined interval in the transport direction 940. The band-shaped glass 910 is divided at the scribe line 911 by the dividing device (moving roller 925) disposed on the downstream side in the transport direction 940 to become the glass plate 1000 (glass cutting step).

  In order to form a scribe line 911 parallel to the width direction 941 of the band-shaped glass 910, the head 951 runs obliquely with respect to the width direction 941. The oblique traveling direction 942 and the width direction 941 of the head 951 form an angle θ that is determined depending on the conveyance speed of the strip glass 910 and the traveling speed of the head 951. The head 951 is guided at a constant speed by being guided by a guide (not shown) that traverses the upper portion of the strip glass 910 in parallel with the oblique traveling direction 942. For convenience, a line on which the head 951 travels is shown as a head travel line 950 in FIG. The head 951 and the guide constitute a crack extension device.

  33 is a cross-sectional view of FIG. 33 along the head travel line 950, and FIG. 35 is a partially enlarged view of FIG. The head 951 includes an optical system 970 for condensing laser light on the belt-shaped glass 910 and an injection nozzle 980 for locally cooling the belt-shaped glass 910 by spraying a coolant. The head 951 further includes a cutter 919 that is a crack forming device that forms an initial crack in the belt-like glass 910.

  The cutter 919 is typically a wheel cutter, but there is no particular limitation on the type thereof as long as a stretchable crack can be formed in the strip glass 910. The cutter 919 plays a role of forming an initial crack serving as a starting point of the scribe line 911 in the strip glass 910. The initial crack is formed at or near the end of the strip-shaped glass 910 (in the case of the strip-shaped glass 910 shown in FIG. 33, the right end in the figure).

  The initial crack extension for forming the scribe line 911 is performed by the laser beam 917 and the coolant 918 supplied from the head 951. In other words, when heating by the laser beam 917 and rapid cooling by the refrigerant 918 are successively applied so as to overlap with the end of the crack, tensile stress is generated on the glass surface in the vicinity of the crack (surface 910f of the strip glass 910). Cracks extend due to stress. The head 951 advances on the head travel line 950 (to the left in the illustrated form) while extending the crack. In the present embodiment, a crack that is formed by extending an initial crack and is capable of dividing the strip glass 910 along the crack in the glass dividing step is referred to as a scribe line 911.

  As shown in FIG. 36, as the head 951 travels, the belt-shaped glass 910 is irradiated with the laser light 917 via the optical system 970, and the coolant 918 is supplied from the injection nozzle 980. The region 928 proceeds along the head travel line 950 in this order. In other words, the cooled region 928 follows the irradiated region 927, and these regions travel along the head travel line 950. The head 951 maintains the relative positional relationship between the laser beam condensing device (optical system 970) that forms the irradiated region 927 and the cooling device (jet nozzle 980) that forms the cooled region 928. The role to move is left. In the present embodiment, the irradiation step of irradiating the laser beam 917 so that the irradiated region 927 of the laser beam 917 on the surface 910f of the strip glass 910 moves from one end side to the other end side of the transverse line in this way. And a cooling step of supplying the coolant 918 to the cooled region 928 that follows the irradiated region 927 in the crossing line. The irradiation step and the cooling step in the present embodiment constitute a scribe line forming step.

Returning to FIG. 35, the laser light irradiation system and the refrigerant supply system will be briefly described. However, these systems can be used without any particular limitation. The laser beam 917 is condensed from the laser beam generator 971 to the irradiated region 927 of the strip glass 910 via the laser beam expanding device 972 and the optical system 970 which is a condensing device in the head 951. The optical system 970 includes optical elements 973, 974, and 975. The laser beam expanding device 972 is configured by, for example, an expander. The optical element 973 is, for example, a pair of axicon lenses, the optical element 974 is a mirror, and the optical element 975 is, for example, a cylindrical lens. As the laser light 917, a CO ₂ laser, a YAG laser, or the like can be used.

  In the present embodiment, the emitted light is emitted from the laser beam generator 971 fixed outside the conveyance path of the strip glass 910. The emitted light is refracted so as to travel along the reference transport surface 961 by an expander 972 fixed outside the transport path of the belt-shaped glass 910, and after passing through a pair of axicon lenses 973, a mirror 974 included in the head 951 and It is converted into a laser beam 917 traveling toward the strip glass 910 by the cylindrical lens 975. The outgoing light immediately after passing through the expander 972 has a Gaussian energy density profile (FIG. 37). Next, it is converted to have a ring-type energy density profile by a pair of axicon lenses 973 (FIG. 38). After being converted into the laser light 917 by the mirror 974 and the cylindrical lens 975, it has a top hat type energy density profile (FIG. 39).

  The refrigerant 918 is supplied from a refrigerant supply device (not shown) to the cooled region 928 via an injection nozzle 980 provided in the head 951. For example, air, nitrogen, helium, or water may be used as the refrigerant. In this embodiment, as shown in FIG. 35, an angle φ is formed between the extending direction of the injection nozzle 980 (the opening direction for injecting the refrigerant) and the direction perpendicular to the reference transport surface 961. Yes. Accordingly, the refrigerant 918 can be injected from the upstream side in the width direction 941 to the cooled region 928 along the direction inclined with respect to the thickness direction of the strip glass 910, and the cooled region 928 is separated from the irradiated region 927. Can be prevented. The angle φ is, for example, 0 to 60 °.

  In the example shown in FIG. 33, the flat (elliptical) shape of the laser light 917 at the reference position 962 that is apart from the back surface 910b of the strip glass 910 by the thickness t of the strip glass 910 in the thickness direction from the back surface 910b of the strip glass 910 as viewed from the reference transport surface 961. The laser beam 917 is irradiated so that the long axis direction 9171 of the cross section coincides with the width direction 941. Thereby, since the major axis direction of the irradiated region 927 coincides with the width direction 941, the amount of heat in the strip glass 910 (the crossing line; the portion where the scribe line 911 is to be formed) can be efficiently given heat. Can do. However, if the laser beam 917 at the reference position 962 has a top-hat type energy density profile that spreads along a transverse line, the major axis direction 9171 may not coincide with the width direction 941. In the present embodiment, “the laser beam 917 at the reference position 962 spreads along the transverse line” means that the cross-sectional shape of the laser beam 917 at the reference position 962 is that of the head 951 when viewed from the belt-like glass 910 being conveyed. It means spreading in a direction parallel to the moving direction.

In this embodiment, the top hat type energy density profile is a flat having an energy density of 0.8 W _max or more when the peak value of the energy density (W / m ² ) at the reference position 962 is W _max. The portion 917f extends to an area that occupies at least half of the whole. According to such a top-hat type energy density profile, even if the belt-like glass 910 vibrates or locally swells during conveyance, the amount of heat supplied to each point on the head travel line 950 is uniform. The scribe line 911 can be formed stably. From the viewpoint of making the formation of the scribe line 911 more stable, the energy density profile of the top hat type excludes at least one-sixth region (both ends 917e in FIG. 39) of the flat portions 917f at both ends 917 in the transverse direction. It is preferable to extend to a region occupying 2/3. In the case where the float method is employed, since the vibration accompanying the conveyance is likely to occur, the effect that the scribe line 911 can be stably formed is particularly effective.

  In the present embodiment, a position where the energy density is 5% of the peak value is handled as both ends of the energy density profile, and a region sandwiched between both ends is handled as constituting the entire energy density profile. Both end portions 917e are portions existing on both end sides of the energy density profile, and the flat portion 917f is a portion sandwiched between both end portions 917e. In the present embodiment, as energy density at each point in the transverse direction (major axis direction 9171) of the laser beam 917 at the reference position 962, energy in a direction (minor axis direction 917s) orthogonal to the transverse direction of each point. The average value of the density is adopted, and the “peak value of the energy density at the reference position 962” indicates the maximum value of the average value. In the top hat type energy density profile of the present embodiment, there is a point where the flat portion 917f has the maximum energy density, and at both end portions 917e sandwiching the flat portion 917f, the energy density decreases as the distance from the center increases.

  In the present embodiment, the length of the flat portion 917f along the crossing line (long axis direction 9171) is 10 to 150 mm, and preferably 20 to 100 mm.

  In the present embodiment, since the emitted light emitted from the laser light generator 971 is converted into the laser light 917 by the pair of axicon lenses and cylindrical lenses, the energy loss at the time of this conversion is small. Considering that energy loss is relatively large when adjusting the energy density profile of laser light using a DOE (diffractive optical element) or the like, the optical system in this embodiment is advantageous from the viewpoint of energy efficiency. You can say that. In addition, the adoption of a pair of axicon lenses and cylindrical lenses means that even if the surface 910f of the strip glass 910 is separated from the reference position 962 by vibration (even if the surface 910f is separated from the focal point of the laser light 917), the flat portion 917f is formed. It is also advantageous in that it is easily maintained.

  In the present embodiment, the laser beam 917 is maintained so that the energy density profile of the laser beam 917 is maintained over a period (a period in which the head 951 crosses the strip glass 910) moving from one end side to the other end side of the transverse line. Irradiate 917. Therefore, the scribe line 911 can be stably formed over a wide area of the head travel line 950. Specifically, in this embodiment, by using the expander 972, the emitted light emitted from the laser light generator 971 is adjusted to parallel light, and the energy density profile of the laser light 917 is maintained.

  In the cooling step in the present embodiment, the thickness direction from the front surface 910f of the strip glass 910 toward the back surface 910b is such that the flat portion 917f of the laser light 917 at the reference position 962 and the refrigerant 918 at the reference position 962 are adjacent to each other. In contrast, the refrigerant 918 is injected along a direction inclined from the upstream side to the downstream side in the transverse direction. As a result, the portion of the irradiated region 927 where the amount of heat supplied is large is rapidly cooled, so that the scribe line 911 is more easily formed.

  Since there is no portion where the energy density protrudes in the above-mentioned top hat type energy density profile, there is a low possibility that a portion that is excessively heated locally in the irradiated region 927 is generated. Therefore, in order to avoid a situation where the initial crack is not extended due to insufficient heat, even if the laser beam output is set to a large value, the glass strip is completely divided due to excessive heat, or unintended cracks (for example, other than the desired direction) There is a low risk that cracks extending in the direction of For this reason, compared with the case where it has an energy density profile of a general Gaussian type or the like, the output of the laser beam can be set higher, and thereby the width direction component of the moving speed of the head can be increased. The output of the laser beam 917 is 30 to 300 W, for example.

  Considering that the phenomenon that the strip glass is completely divided or an unintentional crack is generated due to an excessive amount of heat is likely to appear when the strip glass 910 is thin, the thickness of the strip glass 910 is, for example, 0.1 to 5 mm. In this case, it can be said that the laser beam having the above-mentioned top hat type energy density profile is particularly effective.

  The band-shaped glass 910 on which the scribe line 911 is formed is divided along the scribe line 911 on the downstream side in the transport direction 940. As shown in FIGS. 40A and 40B, when the scribe line 911 of the strip glass 910 approaches, the moving roller 925 lifts the strip glass 910 in the thickness direction. Cracks constituting the scribe line 911 extend due to the stress generated by the weight of the raised glass strip 910, and the glass strip 910 is cut. More specifically, the moving roller 925, which is a glass cutting device, lifts the glass strip 910 so that the amount of displacement of the portion in contact with the moving roller 925 is maximized, and advances the cutting along the scribe line 911. As shown in FIG. 40C, after the division is completed, the moving roller 925 is pulled down to prepare for the next division.

  The moving roller 925 supports the glass strip 910 on the back surface 910b on both the upstream side (left side in the figure) and the downstream side (right side in the figure) across the scribe line 911 so that stress is applied to the scribe line 911. It is lifted upward (FIG. 40 (b)). As the moving roller 925 subsequently descends, the downstream end 910e of the strip glass 910 once moved upward returns to the lower side (FIG. 40C).

  In this embodiment, the cutting at the scribe line 911 is caused to proceed by the stress generated by its own weight. However, when the moving roller 925 is lifted, the strip glass 910 is moved upstream or downstream in the conveying direction 940 of the moving roller 925. The cutting may be advanced by pressing the surface 910f from above. In this way, even when the thin and light strip glass 910 is divided, it is easy to ensure the stress required for the division.

(Reference Embodiment C2)
In the reference embodiment C1, the formation of the scribe line 911 traversing the strip glass 910 has been described. However, the technique described in the reference embodiment C1 is also applicable to the case where the scribe line is formed in parallel with the transport direction 940 of the strip glass 910. Applicable.

  FIG. 41 shows a state in which a strip-shaped glass (glass ribbon) 910 that is unloaded from a glass forming apparatus (not shown) and transported along a reference transport surface 961 that is a horizontal surface is observed from above, as in FIG. 33 and the like. Yes.

  Heads 953a and 953b are arranged above the strip glass 910. Each head 953a, 953b includes the same member as the head 951. As described above, after forming an initial crack with a cutter, a laser beam and a coolant are sequentially supplied to the strip glass 910 to scribe lines 915a, 915b is formed. However, each of the heads 953a and 953b is fixed at a predetermined position on the strip glass 910. For this reason, the heads 953a and 953b move along the length direction of the band-shaped glass 910 relative to the band-shaped glass 910 along with the movement of the band-shaped glass 910 in the transport direction 940. 915a and 915b are formed. The scribe lines 915a and 915b are formed on lines (longitudinal belts) 945a and 945b that pass through the irradiated region to which the laser light is irradiated and the cooled region to which the coolant is supplied and extend in parallel with the transport direction 940. That is, in the present embodiment, the irradiation step of irradiating the laser beam from the fixed position so that the irradiated region and the cooled region of the laser beam on the surface of the belt-like glass 910 are set on the vertical lines (lines 945a and 945b). And a cooling step of supplying the coolant to the cooled region following the irradiated region in the longitudinal line.

  The reference embodiment C2 can be applied to the removal of the side edge of the band-shaped glass 910 that may be called an ear. Moreover, since the width dimension of the glass plate which should be manufactured is small compared with the width dimension of the strip glass 910, it can apply preferably also when the strip glass 910 should be divided along the length direction. In the example shown in FIGS. 42 (a) and 42 (b), the edge portion (side end portion) 902 of the belt-like glass 910 is removed, and the center portion 901 formed to a predetermined thickness has a width on the downstream side in the transport direction. Divided in the direction 941 and sampled as a sheet glass. When the thickness of the sheet glass to be formed is thin, the difference between the thickness of the ear portion 902 and the thickness of the central portion 901 tends to be remarkable as shown in the figure.

  As shown in FIG. 42B, the division along the length direction can also be performed by lifting the strip glass 910 on the left and right sides in the figure across the scribe lines 915a and 915b. In the illustrated form, the belt-shaped glass 910 is lifted by the moving roller 929, and stress is applied to the scribe lines 915a and 915b. However, the division of the strip-shaped glass 910 is not limited to the form shown in FIG. 42B. For example, the center portion 901 is not displaced in the thickness direction of the strip-shaped glass 910, and only the ear portion 902 is moved in the glass thickness direction. It can also be implemented by pushing down.

  In addition, after forming the scribe line 911 which crosses, you may form the scribe lines 915a and 915b which run vertically in the strip | belt-shaped glass 910, and you may form a scribe line in the reverse order. The step of dividing the strip glass 910 may be performed collectively after forming all the scribe lines to be formed, or may be performed alternately with the scribe line forming step of forming the scribe lines. For example, the scribing lines 915a and 915b are formed on the band-shaped glass 910, the band-shaped glass 910 is divided by these lines to exclude the ear part 902, and then the scline line 911 is formed on the center part 901 as a product. It is good also as dividing by a line.

  In the present embodiment, the laser beam 917 at the reference position 962 separated from the back surface 910b of the belt-like glass 910 by the thickness t of the belt-like glass 910 in the thickness direction from the back surface 910b of the belt-like glass 910 as viewed from the reference transport surface 961 is a vertical line (line 945a, The laser beam 917 is irradiated so as to have a top-hat type energy density profile extending along 945b). In the example shown in FIG. 41 and the like, the laser beam is irradiated so that the long axis direction of the cross section of the laser beam at the reference position 962 matches the transport direction 940, and the long axis direction of the irradiated region is matched with the transport direction 940. Thus, heat is efficiently applied to a portion (longitudinal line; portions where the scribe lines 915a and 915b are to be formed) to which heat is to be applied in the strip glass 910.

In the present embodiment, the top hat type energy density profile has at least the entire flat portion 917f having an energy density of 0.8 W _max or more when the peak value of the energy density at the reference position 962 is W _max . It extends to an area occupying 1/2. Accordingly, the amount of heat supplied to each point on the lines 945a and 945b is likely to be uniform, and the scribe lines 915a and 915b can be stably formed. From the viewpoint of making the formation of the scribe line 911 more stable, the top hat type energy density profile is extended to an area that occupies 2/3 of the flat portion 917f excluding at least 1/6 of each area at both ends in the transport direction. Also good.

  The length along the vertical line (long axis direction) of the flat portion 917f is 10 to 150 mm, preferably 20 to 100 mm. Moreover, the output of a laser beam is 30-300W, for example. The thickness of the strip glass 910 is, for example, 0.1 to 5 mm.

  Further, upstream from the downstream side in the transport direction 940 with respect to the thickness direction from the front surface 910f of the strip glass 910 to the back surface 910b so that the flat portion of the laser beam at the reference position 962 and the refrigerant at the reference position 962 are adjacent to each other. You may inject a refrigerant | coolant along the direction inclined to the side.

  Hereinafter, an off-line experiment conducted to confirm that it is advantageous that the laser beam has the above-described energy density profile when the glass strip vibrates during conveyance will be described with reference to FIG. .

(Experiment C1)
As the plate glass 1210, a soda lime glass plate having a thickness of 0.33 mm, a short side length of 100 mm, and a long side length of 200 mm, expressed in mass% and having the following components was prepared.

SiO ₂ : 71.9%
Al ₂ O ₃ : 1.7%
MgO: 4.0%
CaO: 8.0%
Na ₂ O: 13.5%
K ₂ O: 0.9%

  The plate glass 1210 was fixed to the transfer table 1290 so that the direction along the long side of the plate glass 1210 coincided with the transfer direction 1242 of the transfer table 1290.

  An initial crack 1261 was formed in the sheet glass 1210 with the transfer table 1290 stationary. Specifically, an initial crack 1261 having a length of 10 mm is formed, starting from a position 50 mm away from one short side 1210a of the glass sheet 1210 in the direction of the other short side 1210b and extending toward the short side 1210b. did. The initial crack 1261 was formed using a sintered diamond cutter wheel (outer diameter φ2.5 mm, thickness 1.0 mm, inner diameter φ1.1 mm, blade edge angle 135 degrees).

Next, while moving the transfer table 1290, the surface of the plate glass 1210 was irradiated with laser light, and water (refrigerant) was jetted. Specifically, first, the irradiated region 1227 and the cooled region 1228 are initially set at positions ahead of the short side 1210a in the transport direction 1242, and the major axis of the initial crack 1261 and the major axis of the irradiated region 1227 are the same. Then, the position of the transfer table 1290 was initially set so that no gap was formed between the two long axes. Next, the irradiated region 1227 has a length of 24 mm and a width of 0.2 mm (dimension at the beam waist (focal point)), and a laser beam beam waist is formed on the surface of the sheet glass 1210. The laser beam condensing device and the cooling device were adjusted so that the cooled region 1228 was in contact with one end in the length direction of the irradiated region 1227 (FIG. 43A). Next, while maintaining the positions of the irradiated region 1227 and the cooled region 1228 fixed, the transfer table 1290 is moved in the transfer direction 1242 to 384 mm / mm until these positions are downstream of the short side 1210b in the transfer direction 1242. It was moved at a speed of s (relative speed V _RP ) (FIGS. 43B and 43C). The depth of the scribe line (crack 1262) formed at this time was examined.

Specifically, a 60 W laser beam outputted from a CO ₂ laser oscillator (ULC-100 manufactured by UNIVERSAL LASER SYSTEMS) is refracted and reflected using two axicon lenses, a cylindrical lens (depth of focus F = 5 mm) and a mirror. The irradiated region 1227 was set by reflection (hereinafter, a CO ₂ laser oscillator, two axicon lenses, a cylindrical lens, and a mirror may be collectively referred to as an optical system). FIG. 44 shows a top hat type energy density profile possessed by laser light irradiated onto the sheet glass 1210 via this optical system. FIG. 44 is a photograph of a cross section of the acrylic plate after irradiating the acrylic plate with a thickness of 5 mm with this laser beam. From this photograph, it is understood that the length of the flat portion is 24 mm and the length of both end portions is 2 mm. Moreover, the to-be-cooled area | region 1228 was set by injecting the water of 1.5 ml / min of injection quantity from a nozzle (Everloy minimist 04-10-13). The nozzles were installed so as to open in a direction inclined by φ = 10 ° in the direction from the downstream side to the upstream side in the transport direction 1242 when viewed from the direction perpendicular to the main surface of the transport table 1290. In addition, the nozzles were arranged so that an interval of 5.5 mm was formed between the main surface of the transfer table 1290.

  Next, the moving speed of the transfer table 1290 was sequentially changed, and the same experiment was repeated. Further, the same experiment was performed by sequentially moving the optical system and the nozzle in a direction perpendicular to the main surface of the transfer table 1290 (by sequentially changing the height of the optical system and the nozzle). The results are shown in Table 9. In Table 9, a height of 0 mm indicates a state in which a gap of 5.5 mm is formed between the main surface of the transfer table 1290 and the nozzle, and a height of positive indicates that the optical system and A state in which the nozzle is moving away from the glass sheet 1210 is shown, and a negative height indicates a state in which the optical system and the nozzle are approaching the glass sheet 1210. The numerical values other than the moving speed and the height in Table 9 indicate the depth (μm) of the crack (vertical crack) 1262 constituting the formed scribe line (for example, Table 9 shows the transfer table 1290). This indicates that a scribe line having a depth of 120 μm was formed when the moving speed was 192 mm / s and the height was −3.8 mm). It should be noted that the parentheses in the numerical values indicate that although a crack was formed, it was impossible to divide the sheet glass 1210 along the formed crack (that is, the formed crack was It is not a scribe line sufficient to carry out the dividing step as specified in the invention. N indicates that the initial crack 1261 did not expand at all. F indicates that the sheet glass 1210 is completely divided.

  The result of Experiment C1 is a conveyance table 1290 in the case where a scribe line (a crack formed by extending the initial crack 1261 that can cut the glass sheet 1210 along itself, the same applies hereinafter) is formed. It can be seen that there is a minimum value and a maximum value in the moving speed of. The minimum value exists when the moving speed of the transfer table 1290 is excessively slow, the amount of heat per unit area supplied to the sheet glass 1210 becomes excessive, and the sheet glass 1210 is completely divided, This is because unintended cracks (for example, horizontal cracks) may occur. On the other hand, the maximum value exists when the moving speed of the transfer table 1290 is excessively high, the amount of heat per unit area supplied to the sheet glass 1210 is too small, and the stress necessary for the extension of the scribe line is present. This is because it does not occur. In Table 9, the reason why the sheet glass 1210 could not be divided in the case where the numerical values are parenthesized is not clear, but the amount of heat per unit area supplied to the sheet glass 1210 is excessive, and the refrigerant is As a result of the crack extending before reaching, the smoothness of the cross section of the crack may be insufficient, or the extension direction of the crack may be slightly deviated from the predetermined direction.

  Further, from the result of Experiment C1, it is understood that the conditions for forming the scribe line differ depending on the height of the optical system and the nozzle. Specifically, the minimum value and the maximum value of the moving speed of the transfer table 1290 capable of forming a scribe line tend to decrease as the height of the optical system and the nozzle moves away from 0 mm. This is because, in Experiment C1, when the height is 0 mm, the laser beam is irradiated so that the beam waist of the laser beam is formed on the surface of the sheet glass 1210, and in this case, the cooling region 1228 is the irradiated region. This is because the refrigerant is injected so as to come into contact with one end of the length direction 1227. Table 10 shows the relationship between the height of the optical system and the nozzle and the moving speed (minimum value and maximum value) of the transfer table 1290 when the scribe line is formed. The relationship is indicated by a solid line in FIG.

(Experiment C2)
In Experiment C2, the optical system was changed so that laser light having a ring-shaped energy density profile was formed. As a result, a laser beam having a ring-type energy density profile was formed. Otherwise, the experiment was performed in the same manner as Experiment C1. The results are shown in Table 11. In Table 11, “A” indicates that the initial crack 1261 has expanded. Table 12 shows the relationship between the height of the optical system and nozzles and the moving speed (minimum value and maximum value) of the transport table 1290 when a scribe line is formed. The relationship is shown by the dotted line in FIG.

  From FIG. 45, the height of the optical system and the nozzle are set within a certain range in order to make it possible to form a scribe line both in the case of using the optical system of Experiment C1 and in the case of using the optical system of Experiment C2. It is understood that there is a need. 45, it is understood that the width of this range is wider when the optical system of Experiment C1 is used than when the optical system of Experiment C2 is used. That is, from Experiment C1 and Experiment C2, when the scribe line 911 is formed using laser light in online cutting in which the strip glass 910 vibrates during conveyance, the laser light 917 having the above-mentioned top hat type energy density profile is used. It can be said that it is advantageous to use it.

  Further, it can be seen that when the optical system of Experiment C1 is employed, the output of the laser beam can be easily increased while preventing the generation of cracks, compared with the case of employing the optical system of Experiment 2.

  By referring to the reference embodiments C1 and C2 together, the following invention can be derived.

(Reference Invention C1)
By irradiating the strip-shaped glass unloaded from the forming apparatus and being transported in a predetermined transport direction along the reference transport surface, the strip-shaped glass is moved along a transverse line extending in the transverse direction of the strip-shaped glass. A method for cutting a strip glass,
An irradiation step of irradiating the laser beam so that the irradiated region of the laser beam on the surface of the belt-shaped glass moves from one end side to the other end side of the transverse line;
A cooling step of supplying a refrigerant to a cooled region following the irradiated region in the crossing line, and
The top hat type energy density in which the laser beam at the reference position separated by the thickness t of the strip glass in the thickness direction from the back surface to the front surface of the strip glass as viewed from the reference transport surface spreads along the transverse line. Have a profile,
In the top hat type energy density profile, when the peak value of the energy density at the reference position is W _max , a flat portion having an energy density of 0.8 W _max or more occupies at least a half of the whole. It ’s something that expands,
In the irradiation step, the laser beam is irradiated so that the energy density profile of the laser beam is maintained over a period in which the irradiated region moves from one end side to the other end side of the transverse line.
A method for cutting strip glass.

(Reference Invention C2)
In addition to the reference invention 1, the energy density profile of the top hat type is a band-shaped glass in which the flat portion extends to an area occupying 2/3 excluding each 1/6 area at both ends in the transverse direction. Cutting method.

(Reference Invention C3)
In addition to the reference invention C1 or C2, the length of the flat portion along the crossing line is 10 to 150 mm.

(Reference Invention C4)
In addition to any one of the reference inventions C1 to C3, in the cooling step, the flat portion of the laser light at the reference position and the refrigerant at the reference position are adjacent to each other from the surface of the strip glass. A method for cutting strip glass in which the refrigerant is injected along a direction inclined from the upstream side to the downstream side in the transverse direction with respect to the thickness direction toward the back surface.

(Reference Invention C5)
In addition to any one of the reference inventions C1 to C4, a method for cutting a strip glass, wherein the strip glass has a thickness of 0.1 mm to 5 mm.

(Reference Invention C6)
Cutting the glass strip along a longitudinal line extending in the transport direction by irradiating the laser beam onto the glass strip that is unloaded from the molding apparatus and transported in a predetermined transport direction along the reference transport surface; A method for cutting strip glass,
An irradiation step of irradiating the laser beam from a fixed position so that an irradiation region of the laser beam on the surface of the belt-shaped glass is set on the longitudinal line;
A cooling step of supplying a coolant to a cooled region following the irradiated region in the longitudinal line,
The top-hat type energy density in which the laser beam at the reference position separated by the thickness t of the strip glass in the thickness direction from the back surface to the front surface of the strip glass as viewed from the reference transport surface spreads along the vertical line. Have a profile,
In the top hat type energy density profile, when the peak value of the energy density at the reference position is W _max , a flat portion having an energy density of 0.8 W _max or more occupies at least a half of the whole. It is something that expands
A method for cutting strip glass.

(Reference Invention C7)
In addition to Reference Invention C6, the energy density profile of the top hat type is a band-shaped glass in which the flat portion extends to an area that occupies 2/3 excluding at least 1/6 of each end of the transport direction. Cutting method.

(Reference Invention C8)
In addition to the reference invention C6 or C7, the length along the longitudinal line of the flat portion is a cutting method of the strip glass having a length of 10 to 150 mm.

(Reference Invention C9)
In addition to any one of the reference inventions C6 to C8, in the cooling step, from the surface of the strip glass, the flat portion of the laser light at the reference position and the refrigerant at the reference position are adjacent to each other. A method for cutting strip glass in which the refrigerant is injected along a direction inclined from the downstream side to the upstream side in the transport direction with respect to the thickness direction toward the back surface.

(Reference Invention C10)
In addition to any one of Reference Inventions C6 to C9, a method for cutting strip glass, wherein the strip glass has a thickness of 0.1 mm to 5 mm.

DESCRIPTION OF SYMBOLS 10 Strip glass 10e Downstream end 11, 11a, 11b, 11c, 11d, 11x of strip glass 17 Scribe line 17 Laser beam 18 Refrigerant 19 Cutter 21 Transport roller 22 Support body 25 Moving roller 27 Irradiated area 28 Cooled area 40 (Strip glass) ) Transport direction 41 (Strip-shaped glass) Width direction 42 Skew travel direction 50 Head travel line 51 Head 60a Transport height 60b Dividing height 70 Optical system 71 Laser light generator 72 Laser beam expansion device 73, 74, 75 Optics Element 80 Injection nozzle (cooling device)
DESCRIPTION OF SYMBOLS 100 Glass plate 110 Strip glass 110e Downstream end 111 of strip glass 117 Scribe line 117 Laser beam 118 Refrigerant 119 Cutter 121 Transport roller 122,222 Support body 125 Moving roller 127,427 Irradiated area 128,428 Cooled area 140 ) Conveying direction 141 Width direction 142, 242 (Strip glass) Slant running direction 150, 250, Head running line 151, 251 Head 170 Optical system 171 Laser light generator 172 Laser beam expander 173, 174, 175 Optical element 180 Injection nozzle (cooling device)
200 Glass plate 461 Initial crack 462 Crack 410a, 410b Short side 442 Conveying direction 490 (conveying table) Conveying table 510 Band-shaped glass (glass ribbon)
510b Back surface 510e (Strip glass) Downstream end 510f of strip glass 511 Scribe line 517, 817 Laser beam 517w, 817w Beam waist 518.818 Refrigerant 519 Cutter 521 Transport roller 525 Moving roller 527, 827 Irradiated Areas 528 and 828 Cooled area 540 (Strip glass) transport direction 541 (Strip glass) width direction 542 Skew travel direction 550 Head travel line 551 Head 561 Reference transport surface 562 Reference position 570 Optical system 571 Laser light generator 572 Laser beam expanding device 573, 574, 575 Optical element 580 Injection nozzle (cooling device)
600 glass plate 810 plate glass 810a, 810b short side 829 overlap region 830 gap 842 (direction of conveyance table) conveyance direction 861 initial crack 862 crack 890 conveyance table 901 (portion of glass) central portion 902 (edge of band-like glass) side edge Or ear 910 Band glass (glass ribbon)
910b Back surface 910e of strip glass 910f Downstream end 910f of strip glass 911, 915a, 915b Scribe line 917 Laser beam 917e Both ends 917f Flat portion 917l Long axis direction 917s Short axis direction 918 Refrigerant 919 Cutter 921 Transport Roller 925, 929 Moving roller 927, 1227 Irradiated area 928, 1228 Cooled area 940 Transport direction 941 (for strip glass) Width direction 942 Skew travel direction 945 a, 945 b Longitudinal belt 950 Head travel line 951 953a, 953b Head 961 Reference transport surface 962 Reference position 970 Optical system 971 Laser light generator 972 Laser beam expander 973, 974, 975 Optical element 980 Injection nozzle (cooling device)
1000 Glass plate 1210 Sheet glass 1210a, 1210b Short side 1242 Transport direction 1261 (for transport table) Initial crack 1262 Crack 1290 Transport table

Claims (6)

The initial cracks formed in the band glass are removed from the forming apparatus by supplying a laser beam and a coolant to the band glass while conveying the band glass along the reference conveyance surface in the conveyance direction. A laser scribing step for forming a scribe line in the strip glass by extending in the width direction of
A region that straddles the scribe line at a dividing position that is separated from the scribe position where the scribe line is formed at a predetermined distance away from the scribe position where the scribe line is formed while conveying the glass strip formed with the scribe line. A glass cutting step of displacing the belt-like glass in the scribe line by displacing the belt-like glass from the reference transport surface,
In the glass cutting step, the strip glass is transported between the scribing position and the cutting position over a period from when it starts to be displaced from the reference transport surface until it is split at the scribe line and returns to the reference transport surface. The predetermined interval is determined so that at least one scribe line is present in the belt-shaped glass.
A method for cutting strip glass.   The predetermined interval is determined such that at least two of the scribe lines are present in the band-shaped glass being conveyed along the reference conveyance surface between the scribe position and the dividing position over the period. Item 2. A method for cutting strip glass according to Item 1.   The said predetermined space | interval is defined so that the said scribe line may exist in the said strip shaped glass currently conveyed between the said scribe position and the said dividing position over the said period. A method for cutting strip glass. The reference transport surface is a horizontal surface;
The cutting method of the strip glass as described in any one of Claims 1-3 which supports only the lower surface of the strip glass between the said scribe position and the said cutting position over the said period.   The strip glass cutting method according to any one of claims 1 to 4, wherein an interval between the scribe position and the dividing position is set to 2 m to 5 m.   The cutting method of the strip glass as described in any one of Claims 1-5 whose thickness of the said strip glass is 0.1 mm-1.1 mm.