TW201434568A - Method for cutting plate glass - Google Patents

Abstract

The invention includes a fusion cutting process, which cuts a plate glass G in the vicinity of a cutting schedule line X of the plate glass G by laser fusion cutting in parallel with the cutting schedule line X, and forms a tensile stress area W in a position along said cutting schedule line X; and an initial crack forming process, which forms an initial crack C at a point of intersection of the cutting schedule line X and an end part Gs of the plate glass G. Before the fusion cutting process, a processing process is executed to the end part Gs of the plate glass G including the cutting schedule line X, which prevents naturally occurring cutting accompanying tensile stress of laser fusion cutting.

Description

Cutting method of plate glass

The present invention relates to an improved technique for laser fusion cutting using sheet glass as a target for cutting.

As is well known, flat panel display (FPD) or solar cells, other electronic devices used in liquid crystal displays, plasma displays, electroluminescence (EL) displays, organic EL (organic electroluminescence) displays, and the like. In the manufacturing step of the plate glass product, a small area of the plate glass is cut by a large area of the mother glass, or the edge is trimmed along the side of the plate glass.

As a means of cutting the sheet glass in this way, laser fusing has been known to the public. This laser fusing is a method of irradiating a laser along a line to cut extending on a surface of a workpiece to be cut, and fusing by removing a portion melted by heating of the laser. (cutting) the workpiece.

However, this laser blow has the following difficulties. That is, in the progress of the fuse, the portion irradiated with the laser thermally expands due to the heating of the laser, and the peripheral portion thereof is expanded and compressed. Due to this action, the end portion of the workpiece after the fuse is in a state of being twisted and remaining.

In the case where the laser blow is applied to the cutting of the sheet glass, the residual twist-induced cracking of the sheet glass or the like is generated from the viewpoint of adversely affecting the quality of the finally produced sheet glass product. It is necessary to perform the twist removal one by one after the blown plate glass. Therefore, there is a problem that the manufacturing efficiency of the plate glass product after the melting is deteriorated.

Then, as a technique capable of eliminating such a problem of laser fusing, a method disclosed in Patent Document 1 has been proposed. Specifically, in the same document, a method as shown in FIG. 7 is disclosed in which a laser beam is blown in parallel with the predetermined line X in the vicinity of the line to cut X of the sheet glass G, along which the sheet glass G is cut. The position of the predetermined line X is broken, and a tensile stress region W to which tensile stress is applied is sequentially formed, accompanied by the formation of the tensile stress region W, from the sheet glass G containing the start position of the laser fusing. The end portion Gs naturally develops the cut portion CU along the line to cut X, and the end portion Ga (hereinafter referred to as the fuse end portion Ga) formed by the fuse on the sheet glass G is sequentially The ground is separated from the aforementioned sheet glass G.

Advanced technical literature Patent literature

Patent Document 1: Special Table 2012-526721

According to the method disclosed in Patent Document 1, with the development of the cut portion CU (the fuse end Ga is separated by the sheet glass G), since the applied tensile stress is released (the tensile stress region W disappears), Good efficiency to remove the aforementioned residue in the sheet glass G Distorted. As a result, it is possible to eliminate the trouble of performing re-annealing or the like for the purpose of removing the distortion of the sheet glass G after the melting, and it is possible to appropriately eliminate the above-described problem of manufacturing efficiency.

However, even with the methods disclosed in the same document, there are still problems to be solved so far. In other words, the tensile stress region W formed at a position along the line to cut X is from the start position side of the laser fusing parallel to the line to cut X toward the end position side, and the molten glass portion ( It means that the portion where the glass is melted by laser heating is sequentially formed in parallel. Further, the cutting portion CU is developed to follow the tensile stress region W.

At this time, the molten glass portion M and the cut portion CU are in a positional relationship in the vicinity, and sometimes the melted end portion Ga separated by the development of the cut portion CU and the fragment K thereof straddle the molten glass portion M. The case of the irradiation of the laser beam to the sheet glass G is blocked. When such a situation occurs, it is impossible to melt the glass by laser light, and a problem such as a stop in the middle of the fuse is generated, and it is difficult or impossible to stabilize the melting of the sheet glass G.

As described above, the melted end portion Ga separated from the plate glass G is sequentially separated from the sheet glass G by the development of the cut portion CU, and the melted end portion Ga in the middle of the separation is separated therefrom. The end portion Gb (hereinafter referred to as the cut end portion Gb) formed in the sheet glass G collides and rubs, and the cut end portion Gb may be cracked. Therefore, the quality of the cut end portion Gb is lowered, and the result is that the quality of the sheet glass G is lowered.

In view of the foregoing, it is an object of the present invention to provide a glass plate with the implementation The laser of the glass is blown, and when the fusing end is separated from the plate glass, not only the execution of the fusing can be stabilized, but also the improvement technique of the quality of the plate glass after the separation can be avoided.

A method of cutting a sheet glass according to the present invention, which is proposed to achieve the above object, comprising: a fusing step of laser melting the sheet in parallel with the line to cut in the vicinity of a line to cut of the sheet glass a glass, wherein a tensile stress region is formed at a position along the line to cut; and an initial crack forming step of forming an initial crack at an intersection of the line to cut and an end portion of the sheet glass, before performing the fusing step A processing step is performed on an end portion of the sheet glass including the predetermined cutting line, and in the processing step, processing for preventing cutting which is naturally caused by tensile stress due to the laser melting is performed.

According to this method, the processing step is performed before the fusing step is performed, and in the fusing step, when the end portion of the sheet glass is melted, the tensile stress region is sequentially formed along the line to cut. A cutting portion that prevents parallel operation with a molten glass portion (a portion where the glass is melted by heating by laser) (refers to a tensile stress applied in a tensile stress region to cause the sheet glass to be along a line to cut The occurrence of a similar condition that naturally develops. Thereby, in the state in which the cutting portion is not developed at all, the tensile stress region over the entire length of the cutting planned line can be formed. In addition, at the intersection of the cutting line and the end of the sheet glass, the initial crack is used as the starting point, and the melting end of the sheet glass is separated (the development of the cutting portion) is started at the end of the formation of the initial crack. ). The result is that the laser can be blown The separation from the fuse end is performed separately, and the occurrence of a situation in which the melted end portion separated by the development of the cut portion and the debris thereof traverses the molten glass portion and shields the laser beam from the plate glass is prevented. , and can stabilize the frit glass. Further, when the fuse end portion is separated, since the cut portion can be developed at the same time by the tensile stress region formed over the entire length of the cut predetermined line, the melt end portion is separated from the sheet glass at the same time. Further, it is possible to prevent collision and rubbing of the melted end portion and the cut end portion, and to prevent deterioration of the quality of the plate glass after the separation.

In the above method, it is preferable that the processing step is to perform laser cutting, laser fusing, or stress cracking in a direction in which the sheet glass crosses the line to cut. Here, the term "laser cutting" means irradiating a plate glass with a laser, forming a heating portion in the plate glass, and cooling the heating portion by a refrigerant that follows the laser. The thermal stress that occurs is caused by the initial crack formed in the sheet glass as a starting point, and the cut portion is developed to cut the sheet glass, or after the scribe line developed by the cut portion is formed, for example, by applying a bending stress. And the broken state. In addition, the term "laser blowing" means that the plate glass is irradiated with laser light, and the molten glass portion is removed by laser heat to cut the plate glass. In addition, the term "bending stress cracking" means a state in which the plate glass is bent, and the initial crack formed in the plate glass is used as a starting point, and the cut portion is developed and cut by bending stress. kind.

In this way, it is possible to make the end portion of the sheet glass including one end of the planned cutting line which is the initial crack formation position in the case of a crack or the like as much as possible. In a state that does not exist. Therefore, when the laser is blown from the end portion of the sheet glass, the tensile stress region sequentially formed along the line to cut can be more effectively prevented from being parallel to the molten glass portion and treated as a defect. The occurrence of a similar situation in which the cutting portion of the starting point naturally develops.

In the above method, at the time of the aforementioned fusing step, it is preferable to spray an assist gas to the molten glass portion which is melted by the heating of the laser.

In this way, when the laser is blown (fuse step), the molten glass can be smoothly scattered by the pressure of the assist gas. Therefore, the molten glass portion can be removed at a high speed, and the time required for the laser fusing can be shortened. As a result, the manufacturing efficiency of the sheet glass can be improved. Further, it can be found that the value of the tensile stress applied to the tensile stress region can be made larger by the injection assisting gas.

In the above method, the initial crack forming step may be performed by causing the opposite ends of the two sheets of glass melted through the fusing step to collide or slide each other.

In this manner, due to the collision or sliding of the opposite ends of the two sheets of glass, in both of the two sheets of glass, initial cracks are formed at the intersection of the cut line and the end portion of the sheet glass, and the initial crack is formed. As the starting point, the cutting portion is developed at the same time from one end to the other end of the cutting planned line, so that the separation of the fusing end portions of the sheet glass can be simultaneously performed between the two sheets of glass after the melting, and further can be performed. The manufacturing efficiency of the lifting plate glass. Further, in this state, collision or sliding of the opposing fuse end portion can be promoted in the following modes (i) and (ii). (i) The gas is ejected to the surface on the laser incident side of the opposite fusing end portion or the surface on the exit side. (ii) making the melt The broken two sheets of glass pass through an area where vibrations up and down or ultrasonic vibrations occur.

In the above method, it is preferable that the value of the compressive stress applied to the compressive stress region formed adjacent to the tensile stress region is 20 MPa or more and 1 Gpa or less by the fusing step.

In this way, it is possible to avoid breakage of the sheet glass by applying a compressive stress in the region of the compressive stress. In addition, when the cutting portion having the initial crack as the starting point is developed along the line to cut, the cutting portion can be prevented from moving out of the cutting line. In other words, if the value of the compressive stress applied in the region of the compressive stress exceeds 1 GPa, the tensile stress applied in the tensile stress region becomes excessively large, and the development speed of the cut portion becomes excessive and becomes easy. The cut-off line is detached. On the other hand, when the value of the compressive stress is less than 20 MPa, the tensile stress becomes too small, and it becomes difficult to develop the cut portion itself, and there is a risk that the melted end portion cannot be separated from the sheet glass. Further, the value of the compressive stress is more preferably 50 MPa or more and 1 MPa or less. In this manner, the value of the tensile stress is set to a more appropriate range, and the cut portion developed by the tensile stress can be obtained. The pace of development has further turned into a suitable rate of development.

In the above method, it is preferable that the thickness of the sheet glass is 500 μm or less.

In this manner, the separation from the fusing end portion of the sheet glass can be easily performed by the thickness of the thin sheet glass and the tensile stress region formed by the melting (fusing step) of the sheet glass.

In the above method, preferably after the execution of the aforementioned processing steps, Before the execution of the fusing step, the end portion of the sheet glass including the cut line to be cut is subjected to a heat treatment step of heating to a freezing point or higher.

In this way, it is then possible to remove as much as possible the defects occurring at the end of the sheet glass at the time of performing the processing step or after the execution of the fusing step. Therefore, it is possible to more effectively prevent the tensile stress region from being sequentially formed along the line to cut when the laser is blown from the end portion of the sheet glass, in parallel with the molten glass portion and with the defect as The occurrence of a similar situation in which the cutting portion of the starting point naturally develops.

As described above, according to the present invention, when the fusing end portion is separated from the plate glass by the laser fusing of the plate glass, the execution of the fusing can be stabilized, and the deterioration of the quality of the plate glass can be avoided.

G‧‧‧ plate glass

Gs‧‧ End of the plate glass containing the starting position of the laser blow

Ge‧‧‧End of the plate glass containing the end position of the laser blow

X‧‧‧ cut-off line

Xs‧‧‧ cut off the intersection of the planned line and the end of the plate glass

Xe‧‧‧ cut off the intersection of the planned line and the end of the plate glass

XX‧‧‧ path

S‧‧‧The starting position of the laser fuse

E‧‧‧End of the laser blow

H‧‧‧Heating Department

I‧‧‧The Ministry of Cooling

1‧‧‧Laser illuminator

L‧‧‧Laser

2‧‧‧Cooling water jet

F‧‧‧Cooling water

3‧‧‧Auxiliary gas injection nozzle

A‧‧‧Auxiliary gas

M‧‧‧Metal Glass Division

The fuse end of the Ga‧‧‧ plate glass

Cut-off end of Gb‧‧‧ plate glass

V‧‧‧Compressive stress region

W‧‧‧ tensile stress region

D‧‧‧ slag

C‧‧‧ initial crack

CU‧‧‧cutting department

K‧‧‧Shard

Fig. 1 is a plan view showing a method of cutting a sheet glass according to an embodiment of the present invention.

Fig. 2a is a longitudinal sectional front view showing a method of cutting a sheet glass according to an embodiment of the present invention.

Fig. 2b is a longitudinal front view showing a method of cutting a sheet glass according to an embodiment of the present invention.

Fig. 2c is a longitudinal front view showing a method of cutting a sheet glass according to an embodiment of the present invention.

Fig. 3a is a longitudinal sectional front view showing a method of cutting a sheet glass according to an embodiment of the present invention.

Fig. 3b is a plan view showing a method of cutting a sheet glass according to an embodiment of the present invention.

Fig. 4a is a plan view showing a method of cutting a sheet glass according to an embodiment of the present invention.

Fig. 4b is a plan view showing a method of cutting a sheet glass according to an embodiment of the present invention.

Fig. 5 is a longitudinal sectional front view showing a method of cutting a sheet glass according to an embodiment of the present invention.

Fig. 6a is a plan view showing a method of cutting a sheet glass according to an embodiment of the present invention.

Fig. 6b is a plan view showing a method of cutting a sheet glass according to an embodiment of the present invention.

Fig. 6c is a plan view showing a method of cutting a sheet glass according to an embodiment of the present invention.

Fig. 6d is a plan view showing a method of cutting a sheet glass according to an embodiment of the present invention.

Fig. 7 is a plan view showing a conventional method of cutting a sheet glass.

Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. Further, in the present embodiment, the thickness of the sheet glass to be cut is preferably 500 μm or less, more preferably 300 μm or less, still more preferably 200 μm or less, and most preferably 100 μm or less. .

Fig. 1 is a plan view showing a method of cutting a sheet glass according to an embodiment of the present invention. In the present embodiment, first, the same as the sheet glass G is performed in the same figure. The processing steps shown. More specifically, the two paths XX orthogonal to the two planned cutting lines X extending in the longitudinal direction of the sheet glass G (one end side of the cutting planned line X, and the other end side path XX) The heating unit H heated by the irradiation of the laser light L and the cooling unit 1 that cools a part of the heating unit H by the cooling water F that is the refrigerant that follows the laser light L are sequentially formed.

Then, the thermal stress generated by the temperature difference between the heating portion H and the cooling portion I is at the end portion of the sheet glass G in the width direction (direction orthogonal to the longitudinal direction) (in the same figure, The left end portion of the two end portions in which the predetermined line X is extended in parallel is developed with the preliminary crack formed in advance as a starting point, and the plate glass G is cut by the laser. Therefore, the start position S of the laser fusing (fuse step) described below, the end position E, and the end portions Gs and Ge of the sheet glass G including the intersections Xs and Xe of the cut line X and the path XX are formed in the cutting schedule. One end side and the other end side of the line X. The end portions Gs and Ge formed on the one end side and the other end side can be in a state in which defects such as micro cracks are not present as much as possible.

Here, the above-described processing steps (laser cutting) can be performed by, for example, a device as shown in Fig. 2a. As shown in the figure, the device is irradiated with a laser beam L along the path XX extending in the plate glass G in the width direction of the plate glass G (as in the same figure, perpendicular to the paper surface). The laser illuminator 1 and the cooling water ejector 2 that moves along the laser illuminator 1 while ejecting the cooling water F as a refrigerant.

Further, as a processing step of forming the end portions Gs and Ge of the sheet glass G in which defects are not present as much as possible, in addition to the aforementioned laser cutting, the foregoing may be The plate glass G performs laser fusing or bending stress cracking. Further, a cut line may be formed in the sheet glass G, and after the sheet glass G is broken, an end portion Gs or Ge in which defects are not present as possible may be formed by performing an etching process or the like.

The laser blow can be performed, for example, using a device as shown in Figure 2b. As shown in the figure, the device is moved by one side in the width direction of the sheet glass G (in the same figure, in the direction perpendicular to the plane of the paper), while the laser beam L is irradiated along the path XX extending on the sheet glass G. The laser illuminator 1 and the auxiliary gas injection nozzle 3 which sprays the auxiliary gas A to the molten glass portion M which is melted by the irradiation of the laser light L to scatter the molten glass portion M. The auxiliary gas injection nozzle 3 moves in parallel with the laser illuminator 1 and assumes an inclined posture with respect to the front and back surfaces of the sheet glass G. However, it is also possible that the auxiliary gas injector 3 is not necessarily provided.

For example, bending stress cracking can be performed using the device as shown in Fig. 2c. As shown in the same figure, the apparatus is provided with a retainer that bends the sheet glass G in the longitudinal direction (in the horizontal direction in the same drawing) and can maintain the bending stress, and is omitted in the drawing; An initial crack former, which is omitted from the drawing, forms an initial crack C at the intersection of the end of the glass G and the path XX. Then, the cut portion having the initial crack C as a starting point is formed such that the sheet glass G develops in the thickness direction and the sheet glass G is cut along the path XX.

The end portions Gs and Ge formed on the sheet glass G by the execution of the processing step may be heated to a freezing point or higher as a heat treatment step before the execution of the fusing step described below. In this way, it is possible to be as far as possible before the execution of the laser blow (fuse step) The removal of defects occurring at the ends Gs, Ge of the sheet glass G at the time of performing the processing steps or after that. Further, the heat treatment step is not necessarily performed on both the end portions Gs and Ge, and may be performed only on the end portion Gs.

When the heat treatment step is completed, as a fusing step, as shown in Figs. 3a and 3b, the end portion Gs from the start position S containing the laser fusing is directed toward the end Ge containing the end position E and the laser fusing plate glass G . In addition, this laser blow can be performed using a device having the same configuration as the device shown in Fig. 2b.

Thus, by the execution of the laser fusing (fusing step), the portion irradiated by the laser L is not only thermally expanded by the heating of the laser L but also expanded at the peripheral portion thereof. Therefore, in the opposite fusing end portion Ga of the blown sheet glass G, the compressive stress region V to which the compressive stress is applied and the tensile stress applied as the reaction of the compressive stress are formed adjacent to each other in the width direction of the sheet glass G. Stress area W.

At this time, before the fusing step, by performing the processing step and the heat treatment step, the start position S of the laser fusing or the intersection Xs of the end portion Gs of the sheet glass G and the line to cut X is in a state where the defect is removed as much as possible. under. Therefore, in the fusing step, when the laser beam is blown from the end portion Gs, it is possible to prevent the molten glass portion (by laser) by the tensile stress region W sequentially formed along the cutting planned line X. a portion where the glass is melted and the portion where the glass is melted is parallel, and a cut portion having a defect existing at the end portion Gs is used as a starting point (a tensile stress is applied to the tensile stress region W to cause the sheet glass G to follow a line to cut A similar condition that naturally develops when X is cut off. Therefore, the tensile stress region W over the entire length of the cutting planned line X can be formed in a state where the cutting portion is not developed at all.

Here, in the fusing step, the distance from the focus of the laser beam L to the cutting planned line X is preferably 0.5 to 5 mm. Further, the injection pressure of the assist gas A is preferably 0.01 to 1.0 MPa. Further, the angle formed by the ejection direction of the assist gas A and the front and back surfaces of the sheet glass G is preferably 0 to 60°, more preferably 0 to 30°.

The tensile stress applied to the tensile stress region W is maximized in the width direction in the region at a position close to the fuse end Ga. Further, in the tensile stress region W and the compressive stress region V, the development of the wide region is difficult, and it is difficult to directly measure the value of the applied tensile stress. Therefore, in the case where it is determined that the value of the tensile stress of the fuse end portion Ga should be applied, it is adjacent to the tensile stress region W, and the fuse end portion Ga is present in a limited manner, and it is easy to directly measure the application. The value of the compressive stress in the compressive stress region V is determined in place of the tensile stress. In addition, this tensile stress is proportional to the compressive stress.

The value of the compressive stress to be applied to the compressive stress region V is preferably 20 MPa or more and 1 GPa or less. More preferably, it is 50 MPa or more and 1 GPa or less. In this manner, by the compressive stress applied to the compressive stress region V, it is possible to prevent breakage of the sheet glass G, and at the same time, it is possible to prevent the cut portion CU described below from developing along the line to cut X, at the time of self-cutting The line X develops in a state of escape.

Further, when the laser blow (fuse step) is performed, the following effects can be obtained by spraying the assist gas A. That is, by the pressure of the assist gas A, the molten glass can be smoothly scattered, and the molten glass portion can be removed at high speed. Thereby, the plate glass G can be lifted by shortening the time required for the laser fusing. Manufacturing efficiency.

Further, it is found that the injection assisting gas A injection gives a tensile stress larger than the value of the tensile stress applied to the tensile stress region W. In addition, as shown in FIG. 3a, the molten glass which is scattered by the pressure of the assist gas A at the time of the fuse is likely to adhere to the fuse end Ga as the slag D (dross).

When the fusing step is completed, as an initial crack forming step, a crack is cut by a diamond tip, sandpaper, or the like, or by an ultrashort pulse laser operation, as shown in FIG. 4a, at a predetermined line X and The intersection point Xs of the end portion Gs of the plate glass forms an initial crack C. The cut portion CU having the initial crack C as a starting point develops at the same time by the tensile stress applied to the tensile stress region W over the entire length of the line to cut X.

In the tensile stress region W which has already been formed, the initial crack C is developed, and the cut portion CU having the initial crack C as a starting point is developed, and the separation of the fuse end Ga from the sheet glass G is started. Therefore, the progress of the laser fusing and the separation of the fusing end portion Ga can be performed separately, as shown in FIG. 4b, even when the cutting portion CU is developed, the fusing end portion separated by the development of the cutting portion CU Ga or its fragment K does not straddle the molten glass portion and shields the laser beam L from the sheet glass G, and can stabilize the melting of the sheet glass.

Further, when the fuse end portion Ga is separated, the cut portion CU is developed at the same time by the tensile stress region W formed over the entire length of the cut planned line X, since the fuse end portion Ga can be self-applied The glass is separated at the same time, and the cut end Ga is prevented from being cut by the separation of the melted end Ga from the sheet glass G. The broken end portion Gb collides and rubs, and the deterioration of the quality of the sheet glass G can be avoided.

Further, by setting the value of the compressive stress applied to the compressive stress region V within the above-described range of values, the cut portion CU can be developed in an appropriate state. In other words, when the value of the compressive stress applied to the compressive stress region V exceeds 1 GPa, the tensile stress applied to the tensile stress region W becomes excessively large, and the development speed of the cut portion CU becomes excessively high, so that the cut is made. The broken portion CU is easily detached from the cut line X. On the other hand, when the value of the compressive stress is less than 20 MPa, the tensile stress becomes too small, and it becomes difficult to develop the cut portion CU itself, and there is a risk that the melted end portion Ga cannot be separated from the sheet glass.

Further, the fuse end portion Ga is sequentially separated from the sheet glass G, and when the separation of the fuse end portion Ga is completed, the cutting of the sheet glass G is completed. At this time, as shown in FIG. 4b, the compressive stress and the tensile stress applied to the fusing end portion Ga are released along with the separation of the fusing end portion Ga (development of the cutting portion CU), and can be removed more efficiently. The distortion generated by the sheet glass G causes the compressive stress region V and the tensile stress region W to disappear sequentially. As a result, as shown in FIG. 5, in the cut end portion Gb after the end of the cutting, it is possible to prevent the distortion from remaining as much as possible, and it is possible to omit the annealing of the sheet glass G after the cutting is completed again to remove the distortion. trouble.

Further, the initial crack C may be formed not at the intersection Xs of the planned cutting line X and the end portion Gs of the sheet glass G as shown in FIG. 4a, but at the intersection Xe between the planned cutting line X and the end Ge. Further, in the case where such an initial crack C is formed, as shown in FIGS. 6a and 6b, the initial crack forming step can be performed before the fusing step is performed after the processing step is performed. In this case, at the end As shown in FIG. 6c, the cut portion CU from which the initial crack C formed by Ge is used as the starting point is from the tensile stress region W formed by the end portion Gs side of the fusing step toward the end portion Ge side until reaching the end portion Ge. That is, at the beginning of the formation of the tensile stress region W over the entire length of the cutting planned line X, as shown in Fig. 6d, it has been developed since then. Further, for the same reason, the initial crack forming step can be performed in the middle of performing the fusing step.

In addition, according to the cutting method of the sheet glass described above, the molten glass which is scattered at the time of the laser melting is separated from the melted end portion Ga which is easy to adhere, and the sheet glass G after the cutting is completed can be suppressed. In particular, the occurrence of a similar situation in which the slag D remains in the cut end portion Gb gives a secondary effect. Further, by separating the melted end portion Ga by the tensile tension, it is possible to avoid occurrence of defects at the cut end portion Gb as much as possible.

Here, the method of cutting the sheet glass of the present invention is not limited to the one described in the above embodiment. For example, in the above-described embodiment, the processing step is performed on the path along both the one end side and the other end side along the line to cut (in the above embodiment, the laser cut, the laser blow, or the bend) The state of the stress cracking, but it is also possible to perform the fusing step (laser fusing) by performing the fusing step (laser fusing) only on the one end side and using the end portion of the plate glass formed by the processing step as the starting position. Even in this case, the effect of the cutting method of the sheet glass of the present invention can be obtained. Further, in the above-described embodiment, the path existing on one end side and the other end side of the line to cut is orthogonal to the line to cut, but the invention is not limited thereto, and at least the The path intersects the cut line Aspect.

Further, in the above-described embodiment, the laser cutting, the laser fusing, or the bending stress cracking is performed on the sheet glass as a processing step. In other words, the end portion including the start position of the laser blow is formed by cutting the plate glass. However, in addition to these, it is possible to perform etching as an etching step on the end portion including the start position of the laser fuse without being cut. Even in this case, it is possible to prevent the cutting from occurring naturally due to the tensile stress.

Further, in the case where the processing step of cutting the sheet glass such as the etching described above is performed, the initial crack forming step may be performed before the processing step is performed, unlike the above-described embodiment. In this case, if an initial crack is formed at the intersection of the end portion of the sheet glass at the end position including the laser blow and the line to cut, the stretching is sequentially formed when the fusing step is performed after the execution of the processing step. In the stress region, the end portion of the sheet glass that has reached the end position of the laser fusing, that is, the first stretch stress region that extends over the entire length of the line to be cut is formed, and the development of the cut portion is started. Further, in this case, for the same reason, the initial crack forming step may be performed earlier than the execution of the fusing step after the execution of the processing step, but may be performed in the middle of the fusing step.

Further, in the above-described embodiment, the initial cracks are formed by the cracks being formed by the diamond tips or the like after the melted two sheets of glass, but the two sheets of glass after the melting may be opposed. The end portion collides or slides as an aspect of performing the initial crack forming step. In this way, it is caused by the opposite direction of the two plates of glass. In the collision between the ends of the two sheets of glass, the initial crack is formed at the intersection of the cut line and the end of the sheet glass, and the cut portion is the self-cutting schedule. The one end of the wire develops at the same time until the other end, and the separation of the melted end portion of the plate glass can be simultaneously performed between the two plates after the fusing, and the manufacturing efficiency of the plate glass can be further improved.

Hereinafter, a configuration of an apparatus for forming initial cracks by colliding or sliding the opposing fuse ends of the two plate glasses after the fuses will be exemplified. The configuration for colliding the fuse end portion is, for example, a support table for a pair of sheet glass extending in parallel with the line to cut and having the line to cut therebetween interposed therebetween, so as to be able to approach and move away from each other. Composition. According to this configuration, it is possible to cause the opposing melted end portion after the blow to collide with the approach of the two support tables. Further, as a configuration for sliding the fuse end portion, the two support tables can be moved toward each other in the opposite direction to each other in the direction parallel to the direction in which the fuse end portion extends, as long as they can approach each other or move away from each other. According to such a configuration, the opposing fuse end portions after the fuse can be brought into contact with each other in the opposite direction, and can be moved and slid in the opposite directions. Further, in the above-described embodiment, in the case of the configuration as the injection assisting gas, the blown plate glass or the fusing end portion thereof can be vibrated, and the collision or the sliding of the opposite end portions can be promoted by the vibration.

Further, the initial crack forming step may be a part of the slag which is scattered at the time of melting, and is attached to the intersection of the line to cut and the end of the sheet glass as an execution state. In this case, for example, the condition for melting the slag to be easily scattered is known in advance, and when the end position of the sheet glass is blown, the strip is broken. The fuse is executed under the piece. In this manner, a part of the scattered slag adheres to the intersection of the cut line and the end of the sheet glass, and an initial crack is formed by thermal shock or physical impact at that time.

Further, the initial crack forming step can also be carried out as follows. That is, the fusing end portion at the end position of the laser fusing is welded by the heat at the time of fusing, and after the fusing portion is formed, the fusing end portions are pulled apart, and the welded portion is broken, whereby the planned line can be cut and The intersection of the plate glass forms an initial crack.

Further, in the above-described embodiment, the configuration of the apparatus that can perform the processing step for the laser fusing is that the auxiliary gas injection nozzle is provided in an inclined posture on the front and back surfaces of the plate glass, but the auxiliary gas injection nozzle may be provided. The gas jet nozzle is disposed in a vertical posture with respect to the front and back surfaces of the plate glass.

Further, the method for cutting the sheet glass of the present invention can be applied, for example, to continuously cutting a glass ribbon formed by an overflow or a float; or The glass ribbon is wound into a roll-shaped glass roll, which is processed by roll-to-roll (rolling the glass ribbon from the glass roll and applying predetermined processing) The glass ribbon is re-rolled into the glass reel) and the cutting is performed. In this case, the development of the cut portion in which the initial crack is used as the starting point catches up with the preceding molten glass portion (the progress of the laser blow), and it is necessary to pay attention to the step of performing the initial crack formation without performing these parallel operations. opportunity.

G‧‧‧ plate glass

Gs‧‧ End of the plate glass containing the starting position of the laser blow

Ge‧‧‧End of the plate glass containing the end position of the laser blow

X‧‧‧ cut-off line

Xs‧‧‧ cut off the intersection of the planned line and the end of the plate glass

Xe‧‧‧ cut off the intersection of the planned line and the end of the plate glass

XX‧‧‧ path

S‧‧‧The starting position of the laser fuse

E‧‧‧End of the laser blow

H‧‧‧Heating Department

I‧‧‧The Ministry of Cooling

Claims (7)

A method for cutting a sheet glass, comprising: a fusing step of laser melting the sheet glass in parallel with the line to cut in the vicinity of a line to cut of the sheet glass, and cutting along the foregoing cutting line a position of the line forming a tensile stress region; and an initial crack forming step of forming an initial crack at an intersection of the planned cutting line and the end portion of the sheet glass, and performing the aforementioned cutting line before performing the fusing step The processing step is performed at the end portion of the plate glass, and in the above-described processing step, processing for preventing the cutting which naturally occurs due to the tensile stress caused by the above-described laser fusing is performed. The method for cutting a sheet glass according to claim 1, wherein the processing step is to perform laser cutting, laser fusing, or bending stress cracking in a direction in which the sheet glass crosses the line to cut. The method for cutting a sheet glass according to the first or second aspect of the invention, wherein, in the blowing step, the auxiliary gas is sprayed on the molten glass portion which is melted by the heating of the laser. The method for cutting a sheet glass according to any one of the preceding claims, wherein the initial crack forming step is an opposite end portion of the two sheets of glass melted through the fusing step. Execute by colliding with each other or sliding. The method for cutting a sheet glass according to any one of the preceding claims, wherein the tensile stress region is adjacent to the tensile stress region. The value of the compressive stress in the formed compressive stress region is 20 MPa or more and 1 GPa or less. The method for cutting a sheet glass according to any one of the items 1 to 5, wherein the sheet glass has a thickness of 500 μm or less. The method for cutting a sheet glass according to any one of the preceding claims, wherein, after the execution of the processing step, and before the execution of the melting step, the cutting line is included The end portion of the aforementioned plate glass is subjected to a heat treatment step of heating to a point above the freezing point.