JP2018008842A - Method for manufacturing cut glass plate and apparatus for cutting glass blank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cutting method without having the meander of a crack in the vicinity of the start edge of a cutting scheduled line in a method for cutting a glass plate using a thermal shock.SOLUTION: The method for manufacturing a cut glass plate using a thermal shock comprises: the step 1 of irradiating an end portion on the side of the start edge of the cutting scheduled line of a glass blank with infrared light in a dotted pattern to propagate an initial propagating crack from a glass edge on the side of the start edge by the infrared light transmitting the glass blank; and the step 2 of condensing and irradiating the infrared light on the initial propagating crack of the cutting scheduled line or in front of the initial propagating crack to form a propagating crack obtained by propagating the initial propagating crack along the cutting scheduled line. In a region irradiated with the infrared light in the step 1, the glass edge on the side of the start edge of the cutting scheduled line is not included.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for cutting a glass plate using thermal shock, and particularly to a method for cutting a glass plate for construction.

  Conventionally, a method of cutting a glass plate having a thickness of 2 mm or more and 25 mm or less, which is used as a general architectural glass sheet (for example, a glass sheet described in JIS R3202), is a carbide tool blade such as tungsten carbide or polycrystalline diamond. Therefore, a mechanical method has been used in which a scribe line (scratch) is put on the surface on the cutting line and a bending stress is applied in a direction perpendicular to the scribe line to break it.

  However, if a scribe line is inserted using a carbide tool blade as described above, the surface layer portion of the glass plate will be crushed more than necessary, resulting in invisible fine cracks and a small glass. Waste will be generated. Cracks may reduce the strength of the cut surface or deteriorate the glass edge quality of the glass plate after cutting. Further, the glass dust has a problem that it contaminates the cut surface, causes new scratches on the cut surface, and is difficult to remove by washing.

  Then, the method of cut | disconnecting a glass plate without using a carbide tool blade etc. is examined. As typical methods for obtaining a good cut surface, there are various methods using thermal shock caused by laser irradiation. For example, Patent Document 1 discloses a cleaving method for cleaving a glass ribbon to obtain a rectangular glass plate. According to this document, a preliminary crack is formed in the glass edge of the glass plate, local heating is applied in the vicinity of the edge of the preliminary crack, the crack is propagated by moving the heating point, and finally cracking is performed. I went and cleaved the glass plate. In addition, a laser and a combustion flame are mentioned as a local heating means. However, the cutting method using a heating means using a laser has a problem that even if the laser output is high, it is on the order of several hundred watts, so that it becomes impossible to cut when the glass plate is thick.

  In Patent Document 2, heating is performed by a heating burner so that the temperature in the vicinity of the planned cutting line is 130 ° C. or higher, and the temperatures on the left and right sides of the 10 mm wide center area are 45% or higher of the maximum temperature. And the cutting method which propagates the crack (crack) provided in the starting point by carrying out local cooling of this heating part with mist, and performs a split at the end is disclosed. In this document, the residual stress is relaxed by heating the area to be cut, and the heated area is locally cooled with mist, thereby giving a large thermal shock to the cooled part and causing the tensile stress to propagate the crack necessary for cutting. Is generated.

  The present applicant has also applied for a glass sheet cutting device using thermal shock (Patent Document 3). The apparatus collects and irradiates an infrared line heater, and can cut the glass plate in a non-contact and full-body manner, and does not cause a silico or a microcrack.

JP-A-8-231239 Japanese Patent No. 4899975 JP2015-44729A

  The method of cutting the glass plate using the thermal shock described above is more useful than the conventional cutting method using a cemented carbide tool because the quality of the cut surface is improved.

  However, in the method disclosed in Patent Document 2, since the heating means is a burner combustion flame, an area of 10 mm on both ends is heated with respect to the planned cutting line, so there is a possibility that cracks meander in this area. It is expected that it is difficult to propagate cracks linearly.

  Further, as described above, the apparatus for condensing and irradiating the infrared line heater proposed by the present applicant has fewer cutting steps than the method disclosed in the above-mentioned Patent Document 2, and has excellent linearity with a simple operation. Is possible. Increasing the output of the infrared line heater shortens the time required for cutting, but in that case, it has been found that a new problem arises that the cracks slightly meander near the starting end of the planned cutting line.

  Accordingly, an object of the present invention is to obtain a cutting method in which cracks do not meander in a method for cutting a glass plate using thermal shock.

  As a result of intensive studies using the infrared line heater by the present applicant, it was found that the meandering of the crack that occurs near the starting edge of the planned cutting line can be seen slightly inside the glass plate rather than the glass edge on the starting edge side. . This is thought to be because the heat applied to the glass plate is excessive, and the glass edge dissipates heat because it is in contact with the atmosphere. However, heat is accumulated on the inside of the glass plate from the glass edge because heat dissipation is suppressed. It is presumed to be caused by the failure.

  From the knowledge obtained above, it was found that when the infrared spot heater having a lower output than the infrared line heater was irradiated in the vicinity of the glass edge on the start side, the above problem could be solved. Furthermore, it has been newly found that the generation time of cracks from the glass edge is shortened by setting the irradiation position of the infrared spot heater to be slightly inside the glass plate from the glass edge on the start end side.

  Accordingly, the present invention provides a method for producing a cut glass plate using thermal shock, wherein infrared light is irradiated in a dot-like manner on an end portion on the starting end side of a cutting planned line of the glass base plate, Propagating the initial propagation crack from the glass edge on the start side by the transmitted infrared light, and condensing and irradiating infrared light on the initial propagation crack on the planned cutting line or in front of the initial propagation crack, Forming a propagation crack in which the initial propagation crack is propagated along the planned cutting line, and a glass edge on the start side of the planned cutting line is included in the irradiation region of the infrared light in the step 1 It is a manufacturing method of the cut glass plate characterized by not having.

  Further, the present invention provides a glass base plate cutting apparatus using thermal shock, the glass base plate placed on the mounting table has an infrared irradiation device at a position where infrared light can be irradiated, and the infrared irradiation The apparatus is a cutting device for a glass base plate, characterized in that it is a point irradiation device that irradiates infrared light in a dot shape and an infrared line heater.

  As described above, according to the present invention, it has become possible to obtain a cutting method in which cracks do not meander in the vicinity of the start end of a planned cutting line in a method for cutting a glass plate using thermal shock.

It is a simple figure explaining the positional relationship of the cutting edge line of this invention, its both ends, and the glass edge of the start end side and termination | terminus side of a cutting scheduled line. It is the schematic which showed one of the suitable embodiment of the cutting device of this invention. It is a simple figure explaining the cutting method of the present invention. It is a simple figure explaining the termination | terminus crack of the termination | terminus of a cutting projected line. It is a simple figure explaining (a) irradiation position of infrared light of comparative example 1, and (b) formed initial propagation crack. And the irradiation position of the Comparative Example ₂ (a) CO 2 laser, which is a simplified diagram illustrating a an initial propagation cracks that are (b) formed.

1: Explanation of terms Terms used in this specification will be described below. 1A and 1B, the glass base plate G, the planned cutting line L, the end portion 10 of the planned cutting line, and the positional relationship between the starting edge side and the terminating glass edge 1 of the planned cutting line. showed that. Moreover, in this specification, the advancing direction (or the length direction of a glass base plate) of a propagation crack becomes a X direction, the width direction of the glass base plate orthogonal to a X direction becomes a Y direction, and it becomes a cut surface after glass cutting. The thickness direction of the glass base plate was taken as the Z direction.

(Glass base plate)
The glass base plate G refers to a glass plate to be cut. For example, a float plate glass immediately after sampling, a glass plate as a material for obtaining a glass plate of a predetermined shape, and the like can be mentioned.

(Cut glass plate)
The cut glass plate refers to a glass plate obtained by cutting the glass base plate G described above. Moreover, the cut glass plate obtained by this invention has a mirror surface in the cut surface immediately after cutting | disconnection.

(Scheduled cutting line)
The planned cutting line L refers to a straight line that defines a position for cutting on the glass base plate G. Further, “the end portion 10 of the planned cutting line” refers to the end portion of the planned cutting line L on the XY plane, and particularly the negative side in the X direction that generates the initial propagation crack is “the starting end 10a of the planned cutting line”. Further, the plus side in the X direction may be set as “the end 10b of the planned cutting line”. Further, “on the planned cutting line” refers to the XY plane including the planned cutting line L. In addition, the XZ plane including the planned cutting line L becomes a cut plane after cutting, and a virtual plane corresponding to the cut plane before cutting is defined as a “planned cutting plane”.

(Glass edge)
The glass edge 1 indicates a ridge portion of the glass base plate G that is in contact with the planned cutting line L. Further, it may include a line that extends downward from the ridge portion perpendicularly to the YZ plane. In general, the glass edge 1 is a portion in the glass base plate G that is considered to have relatively low strength.

(Irradiation area)
The irradiation region refers to a range of the glass base plate G irradiated with infrared light. In addition, the irradiation area on the XY plane may be referred to as “irradiation point”. When condensing and irradiating infrared light, when the focal point is on the XY plane, the focal point and the irradiation point substantially coincide. Moreover, the inside of the glass base plate G which advanced to the Z direction from the irradiation point shall refer to the range which the infrared light advanced.

(Dots)
“Spots” such as “irradiating infrared light in a spot” may be referred to as “spots” or “spots” in a general light-emitting device, and the width and length are not particularly limited. Absent. For example, both width and length may be about 20 mm or less.

(Infrared light)
The infrared light in this specification refers to light having a wavelength of near infrared to mid infrared. Moreover, it is good also as infrared rays with a wavelength of 780-4000 nm specifically.

2: Cutting device for glass base plate The cutting device of the present invention will be described below with reference to FIG. Although FIG. 2 uses one infrared spot heater 20 and one infrared line heater 21 as the infrared irradiation device, the present invention is not limited to this, and a plurality of each may be used. Further, a semiconductor laser or the like may be used instead of the infrared spot heater 20, and the infrared spot heater 20 or the like may be used instead of the infrared line heater 21. In FIG. 2, the rotating roll 41 and the infrared irradiation device are fixed to the portal frame 30 as the mounting table 40 on which the glass base plate G is placed, but the invention is not limited thereto.

  The present invention, in a cutting device for glass base plate G using thermal shock, has an infrared irradiation device at a position where infrared light 22 can be applied to glass base plate G placed on mounting table 40, The infrared irradiation device is a cutting device for the glass base plate G, which is a point irradiation device (infrared spot heater 20 in the figure) and an infrared line heater 21 that irradiates infrared light in a dot shape.

(Glass base plate G)
As the glass base plate G, a plate-like glass having a thickness of 2 mm or more and 25 mm or less used as a general architectural plate glass (for example, a plate glass described in JIS R3202) is preferable. However, it is not limited to this thickness, and even a thicker glass plate can be cut by the method of the present invention.

  The glass base plate G is not particularly limited as long as it absorbs infrared light 22, and examples thereof include soda lime glass, quartz glass, borosilicate glass, and aluminosilicate glass. Moreover, if it is a brittle material which absorbs the infrared light 22 and causes thermal distortion like glass, it is considered that it can be cut like the glass base plate G. Examples of such brittle materials include various ceramic plates such as alumina plates.

(Infrared irradiation device)
The infrared irradiation device is a device that condenses and irradiates the infrared light 22 onto the planned cutting line L and the planned cutting surface, and includes an infrared light source that emits the infrared light 22. Moreover, in the case of the light source which condenses the infrared light 22 like the infrared line heater 21 or the infrared spot heater 20, it has a condensing part which condenses the infrared light 22 further. In this specification, at least the infrared spot heater 20 is used as the infrared irradiation device, and the infrared spot heater 20 and the infrared line heater 21 are used as a preferable mode as shown in FIG.

  The infrared light 22 irradiated from the infrared irradiation device is partially absorbed when entering the glass base plate G, and the infrared light 22 that has not been absorbed travels inside the glass base plate G. In addition, the infrared light 22 traveling inside the glass base plate G is also partially absorbed, and the infrared light 22 that has not been absorbed travels further inside the glass base plate G. In this way, the absorbed infrared light 22 increases the temperature of the irradiation point and the planned cutting surface. And when the glass base plate G maximum temperature of an irradiation point will be about 60-70 degreeC or more, propagation of the crack 2 will generate | occur | produce. The maximum temperature and heating time when the crack 2 propagates depend on the output of the infrared irradiation device, the thickness of the glass base plate G, the strength of the glass edge, the type of glass, etc. In the case of the glass sheet for building, when the light is condensed and irradiated using the infrared spot heater 20 and the maximum temperature of the irradiation point of the glass base plate G becomes about 100 ° C. or more, the propagation of the crack 2 tends to occur. .

  What is necessary is just to select suitably the wavelength of the infrared light 22 emitted from an infrared irradiation apparatus from near infrared rays, middle infrared rays, etc. Glass generally has a transmittance in the near-infrared region of about 30 to 85%, and light in the near-infrared region is more easily absorbed in the entire plate thickness direction than in other wavelength regions.

  Further, by transporting the infrared irradiation device in the X direction, the crack 2 can be propagated to the end 10b of the planned cutting line L even when the planned cutting line L is longer than the irradiation region of the infrared light 22. . Further, when the sheet is conveyed in the Y direction, the position of the planned cutting line L can be selected as appropriate. Further, in the case of an infrared irradiation device having a condensing unit, it is possible to change the position of the focal point by moving the condensing unit up and down in the Z direction. As described above, a moving mechanism for moving the infrared irradiation device in each direction may be provided.

  Although the condensing part which is not illustrated should just condense said infrared light 22, for example, reflective mirrors, such as a concave mirror, are mentioned. When using a reflecting mirror, it is installed so as to face the irradiation surface of the glass base plate G with an infrared light source interposed therebetween. Moreover, in order to condense the infrared light 22 emitted from the infrared light source without waste, it is preferable to install a reflecting mirror so as to cover the infrared light source. Further, when the reflecting mirror surface is gold-plated, the reflectance is improved and the infrared light 22 can be collected more efficiently.

  In addition to the above reflecting mirror, various lenses such as a cylindrical lens may be used. When using a cylindrical lens, it is installed between the infrared light source and the glass base plate G.

  For the purpose of increasing the cutting accuracy, it is preferable to reduce the irradiation width and the irradiation diameter at the irradiation point of the infrared light 22 as much as possible. For example, in the case of the infrared line heater 21, the irradiation width is generally set to about 1 to 5 mm, but is not limited to this. In order to further narrow the irradiation width, a light shielding slit (not shown) may be used.

  The infrared irradiation device preferably includes a cooling device (not shown) capable of cooling the filament of the infrared light source. The cooling device only needs to be able to cool the filament. For example, a circulating cooling device that includes a flow path in the vicinity of the filament and allows cooling water to flow through the flow path can be used. Excessive heat generation of the filament may shorten the life of the infrared light source or cause a failure of the device, but excessive heat generation can be suppressed by using the above circulating cooling device. The cooling device is not particularly limited as long as it is an existing one, and may be an air cooling device or the like in addition to the device using the cooling water.

(Spot irradiation device)
The point irradiation device is an infrared irradiation device that irradiates the infrared light 22 in a dot shape, and is not particularly limited as long as it emits the above-described infrared light (infrared light having a wavelength of 780 to 4000 nm). Examples thereof include an infrared spot heater 20, a semiconductor laser, a titanium sapphire laser, a fiber laser, a disk laser, and a YAG laser. It is preferable that the infrared spot heater 20 is used for focused irradiation because it is visible and can be used safely. In addition, if a laser emitting light in the wavelength range of 780 to 4000 nm, such as a semiconductor laser, a titanium sapphire laser, a fiber laser, a disk laser, or a YAG laser, is used, it is easy to reduce the irradiation diameter and an improvement in cutting accuracy can be expected. preferable. These lasers may or may not be condensed.

  Below, embodiment using the infrared spot heater 20 as a point-like irradiation apparatus is described.

(Infrared spot heater 20)
The infrared spot heater 20 collects and irradiates the infrared light 22 on the end portion on the start end side of the planned cutting line L, thereby generating the initial propagation crack 2b as shown in FIG. At this time, by not including the glass edge 1 on the start end side in the irradiation region, the temperature difference between the glass edge 1 and the irradiation region 23 of the infrared light 22 is increased, and the tensile stress generated in the glass edge 1 is increased. It is possible to make it easy to generate the initial propagation crack 2b.

  As described above, the smaller the focal spot irradiation diameter of the infrared spot heater 20 is, the better the cutting accuracy is. In the examples of the present specification, the initial propagation crack 2b having a good cutting accuracy could be generated with a diameter of about 8 mmφ. Further, as a result of studies by the present inventors, it has been found that cracks may propagate from the glass edge outside the planned cutting line L if the irradiation diameter becomes too large. Therefore, the irradiation diameter may be, for example, 1 mmφ or more and less than 20 mmφ.

  The output of the infrared spot heater 20 when the infrared light 22 is irradiated may be as strong as the initial propagation crack 2b does not meander. When the initial propagation crack 2b is generated using the infrared line heater 21 having an output of about 2 kW in the same manner as the infrared spot heater 20 of the present invention, the initial propagation crack 2b may meander. This was found by the inventors' investigation. This is considered to be caused by excessive heating. Since the infrared spot heater 20 used in this embodiment is about 100 W, the output of the infrared spot heater 20 to be used may be, for example, 500 W or less.

(Infrared line heater 21)
The infrared line heater 21 further propagates a crack from the initial propagation crack 2b and generates a propagation crack 2c by condensing and irradiating the infrared light 22 onto the planned cutting line L in the propagation direction of the initial propagation crack 2b. At this time, even if the initial propagation crack 2b and the irradiation region overlap, the initial propagation crack 2b may be irradiated on the cutting planned line L about several millimeters ahead (X direction plus side).

  As long as the infrared line heater 21 raises the temperature of the region including the planned cutting surface by the infrared light 22, the lamp length and the lamp output may be appropriately selected. In the embodiment of the present invention, the infrared line heater 22 having an infrared lamp length of 120 mm and an output of 2100 W was used.

  Further, when comparing the infrared line heaters 21 having the same output, the cutting speed tends to be higher when the length of the infrared lamp as the infrared light source is longer. In order to increase the length of the infrared lamp, the infrared line heater 21 having a long infrared lamp may be used. For example, a plurality of infrared line heaters 21 may be arranged in a straight line. At this time, if the distance between the infrared lamps is wide, a good cut surface may not be obtained. Therefore, it is desirable to make the distance as narrow as possible. Even if the above-mentioned distance is, for example, about 2 cm, no problem occurs in cutting the glass base plate G.

  The use of the infrared line heater 21 is preferable because the propagation crack 2c can be efficiently formed, but other infrared irradiation devices may be used. For example, an infrared spot heater 20 having an output of 1000 W or more may be used, or a plurality of units may be arranged in a line and irradiated with light.

(Transport mechanism)
FIG. 2 includes a portal frame 30 and a transport rail 36 as a moving mechanism of the infrared irradiation device. The portal frame 30 includes a support column 31 and a bridging rod 32, and each infrared irradiation device is moved in the X direction along the bridging rod 32 via a slider 33 connected to the infrared spot heater 20 and the infrared line heater 21. move. Further, the transport rail 36 enables the portal frame 30 to be moved in the Y direction. In FIG. 2, both the portal frame 30 and the conveyance rail 36 are provided, but the present invention is not limited to this.

(Gate-type frame 30)
In FIG. 2, a portal frame 30 is used for holding and transporting the infrared irradiation device. The portal frame 30 is arranged so as to cross the glass base plate G in the width direction (X direction), and the infrared irradiation device so that the infrared irradiation device and the surface of the glass base plate G (XY plane) are kept parallel. Hold. The portal frame 30 includes a slider 33 that can move in the X direction right above the glass base plate G. The slider 33 has a through hole in the X direction, and the bridging rod 32 is inserted through the through hole. The slider 33 is also connected to the infrared irradiation device to fix the position of the infrared irradiation device in the Y direction and the Z direction, and at the same time, the slider 33 moves the infrared irradiation device in the X direction to enable positioning in the X direction. Yes.

  In FIG. 2, a rotating unit 34 is provided between each infrared irradiation device and the slider 33. The rotating unit 34 can change the direction of the infrared irradiation device or adjust the position. In addition, when the infrared light 22 is condensed and irradiated in a line shape like the infrared line heater 21, it is possible to propagate the crack 2 in the Y direction by changing the direction by 90 degrees by the rotating unit 34.

  In FIG. 2, both the infrared spot heater 20 and the infrared line heater 21 are installed in the portal frame 30. By doing in this way, it becomes easy to align an irradiation point on the cutting projected line L. Further, since the infrared spot heater 20 irradiates the start end 10 a of the planned cutting line L, it is desirable to install the infrared spot heater 20 closer to the start end 10 a of the planned cutting line L than the infrared line heater 21. Further, instead of the portal frame 30 as described above, each infrared irradiation device may be supported by a pole or the like.

(Transport rail 36)
The portal frame 30 is movably installed on the transport rail 36. The portal frame 30 includes a transport slider 35 below the support column 31, and moves on the transport rail 36 in the Y direction via the transport slider 35. This is effective when the infrared light 22 is irradiated without transporting the glass base plate G, or when the propagation speed of the propagation crack 2c is adjusted by irradiating the infrared light 22 while being transported.

  The portal frame 30 may have a lifting device (not shown) that lifts and lowers the infrared irradiation device. By allowing the infrared irradiation device to move up and down, the focal position of the infrared light 22 can be freely adjusted when the infrared irradiation device has a condensing part.

(Mounting table 40)
The mounting table 40 holds the glass base plate G in a predetermined position. In FIG. 2, a plurality of rotating rolls 41 are used as the mounting table 40, but a normal work table having no transfer function may be used. Further, it is desirable that the portion immediately below the planned cutting line L is not in contact with the back surface of the glass base plate G. This is because there is a concern that the mounting table 40 may be damaged by heat after long-term use due to irradiation of the infrared irradiation device. Further, by contacting the back surface of the glass base plate G on the planned cutting line L, depending on the material of the mounting table 40, it is conceivable that heat radiation from the back surface is hindered, or conversely, the back surface is unnecessarily cooled.

(Control part)
The cutting device of the present invention may be provided with a control unit (not shown). The control unit is connected to the mounting table 40, an infrared irradiation device, a transport mechanism, and the like, and enables each device to be remotely operated by a computer or the like.

(Cooling mechanism)
The cutting device of the present invention may be provided with a cooling mechanism (not shown). The cooling mechanism has a spout, and sprays a cooling fluid onto the end 10b of the planned cutting line L of the glass base plate G from the spout. Since the propagation crack 2c tends to reduce the propagation speed near the end 10b of the planned cutting line L, it is possible to propagate the end crack 2d from the front surface to the back surface of the glass base plate G by providing the cooling mechanism. It becomes.

  The cooling fluid is not particularly limited, but it is preferable to use compressed air. It is only necessary to generate a temperature difference between the surface and the inside of the heated part by performing forced cooling, and to generate a tensile stress on the surface, for example, uncompressed air, water, mist, etc. Good. At this time, the temperature of the fluid is not particularly limited. For example, the temperature in the vicinity of the ejection port may be 40 ° C. or lower, preferably room temperature or lower.

  Further, the cooling device may be connected to the infrared line heater 21 or the like, or may be operated by a handheld by an operator.

3: Manufacturing method of cut glass plate The manufacturing method of the cut glass plate of this invention is demonstrated referring FIG. 3 below.

  The present invention provides a method for producing a cut glass plate using thermal shock, which irradiates infrared light in a dot-like manner on an end portion on the starting end side of a planned cutting line of the glass base plate and transmits the glass base plate. Propagating the initial propagation crack from the glass edge on the starting end side by infrared light, and condensing and irradiating infrared light on the initial propagation crack on the planned cutting line or in front of the initial propagation crack, Forming a propagation crack that propagates the propagation crack along the planned cutting line, and the irradiation region of the infrared light in the step 1 does not include the glass edge on the starting end side of the planned cutting line. A method for producing a cut glass plate characterized by the following.

(Process 1)
First, as shown in FIG. 2A, infrared light 22 is radiated in the form of dots on the end portion 10 on the starting end side of the planned cutting line L of the glass base plate G (in the figure, the infrared spot heater 20 is irradiated). 2), and the initial propagation crack 2b is propagated from the glass edge 1 by the infrared light 22 transmitted through the glass base plate G as shown in FIG. At this time, as described above, the irradiation region of the infrared light 22 does not include the glass edge 1 on the start end side of the planned cutting line L.

  The irradiation area 23 of the infrared spot heater 20 is a range several millimeters away from the glass edge 1 on the start end side toward the plus side in the X direction. This is because the temperature difference between the glass edge 1 and the irradiation region 23 is increased by not heating the glass edge 1, and a tensile stress is efficiently generated in the glass edge 1. At this time, the distance between the glass edge 1 and the irradiation region 23 may be determined according to the irradiation diameter or output of the infrared spot heater 20. Further, for example, irradiation may be performed on the planned cutting line L that is 1 to 20 mm away from the glass edge on the starting end side of the planned cutting line L and is separated to the X direction plus side.

  The irradiation time of the infrared spot heater 20 is not particularly limited. When the maximum temperature of the glass base plate G in the vicinity of the focal point is 60 to 70 ° C. or higher, the initial propagation crack 2b is generated. Therefore, the infrared spot heater 20 may be irradiated until the initial propagation crack 2b is generated. In the examples of the present specification, the initial propagation crack 2b was observed in about 20 to 30 seconds from the start of irradiation of the infrared spot heater 20.

  The generated initial propagation crack 2b extends over the entire thickness of the glass base plate G and propagates to the irradiation region. In addition, the initial propagation crack 2b has good linearity and no cutting edge is seen on the cut surface.

  Moreover, it is preferable to form the initial crack 2a in the glass edge 1 on the start end side on the planned cutting line L before the step 1. The method for forming the initial crack 2a is not particularly limited, and may be such that it is shallowly scratched with a glass cutter or the like. By forming the initial crack 2a, the strength of the glass edge 1 on the start end side is greatly reduced. Therefore, the initial crack 2a becomes the starting point of the initial propagation crack 2b, and the irradiation time of the infrared light 22 can be shortened. .

(Process 2)
Next, as shown in FIG. 3C, infrared light 22 is focused and irradiated on the initial propagation crack 2b on the cutting planned line L or in front of the initial propagation crack 2b, so that the initial propagation crack is obtained. A propagation crack 2c is formed by propagating 2b along the planned cutting line L. In addition, said "front" shall point out the X direction plus side of the planned cutting line L. FIG. Even if the initial transmission crack 2b overlaps the irradiation region of the infrared light 22, the front may be irradiated about several millimeters from the initial transmission crack 2b. Further, the distance between the irradiation region and the initial propagation crack 2b when irradiating the front is not particularly limited as long as the initial transmission crack 2b propagates, but may be, for example, about 20 mm or less.

  The propagation crack 2c is a crack further propagated by the initial propagation crack 2b, and the initial propagation crack 2b and the propagation crack 2c are not significantly different in appearance. When the initial propagation crack 2b is formed using the infrared line heater 21, the initial propagation crack 2b meanders excessively, but the present invention forms the initial propagation crack 2b using the infrared spot heater 20. The above meandering was improved. However, if the propagation crack 2c is further formed using the infrared spot heater 20, the propagation speed of the propagation crack 2c tends to be insufficient due to the low output of the light source and the narrowness of the irradiation area. Therefore, it is preferable to use the infrared line heater 21 as an infrared irradiation device for forming the propagation crack 2c. Even when the infrared spot heater 20 is used, the propagation speed can be improved, for example, by using a high-power infrared light source or by condensing and irradiating an ellipse and aligning the long axis with the planned cutting line L. Is possible.

  Moreover, when forming the propagation crack 2c, you may start irradiation of the infrared light 22 before the temperature of the surface of the glass base plate G falls to about room temperature. As a result of examination by the present inventor, the formation of the initial propagation crack 2b and the formation of the propagation crack 2c tend to require a longer time for the formation, and the propagation crack after the initial propagation crack 2b occurs. It was found that 2c can be formed in a relatively short time. In this example, when the initial propagation crack 2b was generated and the irradiation with the infrared light 22 was started immediately, the propagation crack 2c was generated in about 1 second from the start of the irradiation.

  When the infrared irradiation device is not moved, the propagation crack 2c propagates to the end of the irradiation region. Here, when the irradiation region of the infrared light 22 is shorter than the length of the planned cutting line L, after the propagation crack 2c occurs, the infrared irradiation device is attached to the glass base plate G as shown in FIG. It is desirable to move it relatively. By moving in this way, it is possible to propagate the propagation crack 2c to the end 10b of the planned cutting line L. At this time, either the glass base plate G or the mounting table may be moved.

  When the infrared irradiation device is moved relatively, the moving speed may be matched with the propagation speed of the propagation crack 2c, and is not particularly limited. For example, as shown in FIG. 3D, the infrared irradiation device may be moved in accordance with the tip of the propagation crack 2c.

  The propagation crack 2c tends to have a slow propagation speed near the end 10b of the planned cutting line L. Therefore, it is preferable to cool the surface of the terminal end 10b of the planned cutting line L after the propagation crack 2c has propagated to the terminal end 10b. Cooling can be performed by blowing compressed air, water, or mist from a cooling mechanism such as an air gun. By cooling the surface of the terminal end 10b, a terminal crack 2d is generated from the surface of the glass base plate G to the back surface as shown in FIG. This is presumably because the surface of the glass base plate G is rapidly cooled by compressed air or the like, and a tensile stress is induced on the surface of the glass base plate G due to a temperature difference between the surface of the glass base plate G and the inside.

  When cooling the end 10b of the planned cutting line L, the infrared light 22 may be irradiated or may be stopped. Further, since a tensile stress is induced on the surface, it is preferable to start cooling when the surface temperature of the glass base plate G is as high as possible. Moreover, the timing which starts cooling is good also when the propagation speed of the propagation crack 2c falls large. Although this timing varies depending on the thickness and size of the apparatus and the glass base plate G, the propagation speed tends to greatly decrease at a position where the distance from the glass edge 1 on the end 10b side of the planned cutting line L is about 20 to 50 mm. is there.

  As shown in FIG. 4, the terminal crack 2 d may not be a crack over the entire thickness of the glass base plate G. In that case, after forming the terminal crack 2d, when a force is applied so as to break the glass base plate G from the start end 10a side of the planned cutting line L, as shown in FIG. It becomes possible to propagate the crack 2 over the entire length.

  Further, the propagation crack 2c may be propagated to the end 10b of the planned cutting line L without providing the cooling step. Moreover, if the non-propagating part of the crack 2 is about several millimeters, the cutting may be completed by applying a force so as to break from the start end 10a side without providing a cooling step.

(Cut glass plate)
The cut glass plate obtained has a mirror surface on the cut surface. Moreover, the linearity of the cut surface was good, and the meandering of the cut surface was suppressed.

  Examples and Comparative Examples of the present invention are shown below.

Each infrared irradiation apparatus and glass base plate used are shown below.
Infrared spot heater: HPF-35 manufactured by Heat Tech Co., Ltd. (output 100 W, condensing diameter 8 mmφ, focal length 30 mm)
Semiconductor laser: HL-FAP60 manufactured by Coherent (wavelength 808 nm, output 20 W, condensing 1 mm □, focal length 70 mm)
Infrared line heater: HYL25-28 manufactured by Hybek (output 2100 W, lamp length 12 cm, focal length 25 mm)
Glass base plate: Float plate glass (soda lime glass, 250 mm x 300 mm, thickness 15, 19, 25 mm)

  A mounting table having a rotating roll was used as the mounting table, and the back surface just below the planned cutting line was placed in contact with air. Moreover, said infrared irradiation apparatus was connected using the portal frame | frame, and it was made possible to convey along a cutting scheduled line.

Example 1
First, a glass base plate was installed on the mounting table, and an infrared spot heater and an infrared line heater were installed on the planned cutting line at a position where it could be focused and irradiated. At this time, the planned cutting line was the center in the Y direction (125 mm in the Y direction). Next, the glass edge on the starting end side on the planned cutting line was shallowly scratched with a glass cutter to form an initial crack.

(Process 1)
Next, an infrared spot heater was condensed and irradiated at a position 10 mm away from the glass edge on the start end side toward the X direction plus side of the planned cutting line. At this time, the infrared spot heater was not moved, but fixed irradiation was performed. About 20 to 30 seconds after the start of irradiation, an initial propagation crack was generated starting from the initial crack.

(Process 2)
Next, the infrared line heater was focused and irradiated onto the planned cutting line so as to overlap the tip of the initial propagation crack. At this time, the focal point was set to the XY plane of the glass base plate, and the irradiation width on the XY plane was set to 3 mm. Propagation cracks occurred in about 1 to 3 seconds from the start of irradiation. Next, the infrared line heater was transported at about 1 m / min, and the propagation speed of cracks decreased with the end of the planned cutting line remaining at about 5 mm, so the infrared line heater was turned off.

  Next, by holding the starting end side of the planned cutting line by hand and opening the glass base plate in the horizontal direction, the propagation crack was propagated to complete the cutting.

  The cut surface of the obtained cut glass was a mirror surface, and the cut surface did not meander. Moreover, generation | occurrence | production of glass scraps, such as Kiriko, was not seen. Moreover, with any glass base plate of any thickness used, a cut glass having a mirror surface and no meandering was obtained.

(Example 2)
Except for using a semiconductor laser in place of the infrared spot heater, Step 1 was performed in the same manner as in Example 1 to form an initial propagation crack, and the initial crack started 20-30 seconds after the start of irradiation. An initial propagation crack occurred. Next, Step 2 and subsequent steps were performed in the same manner as in Example 1, and cutting was completed in substantially the same manner as in Example 1. The cut surface of the obtained cut glass was a mirror surface, and the cut surface did not meander. Moreover, generation | occurrence | production of glass scraps, such as Kiriko, was not seen. Moreover, with any glass base plate of any thickness used, a cut glass having a mirror surface and no meandering was obtained.

(Comparative Example 1)
An infrared line heater was used as the infrared irradiation device, and the irradiation area 23 having a distance from the glass edge on the start end side of the planned cutting line L as shown in FIG. Step 1 was performed in the same manner as in Example 1 to create an initial propagation crack 2b. At this time, the focal point was set to the XY plane of the glass base plate, and the irradiation width on the XY plane was set to 3 mm. The initial propagation crack 2b occurred in the irradiation region 23 in about 8 seconds after the start of the focused irradiation, but the generated initial propagation crack 2b is Y with respect to the planned cutting line L as shown in FIG. About 3 mm meandered in the direction. In addition, although the irradiation width of this comparative example was narrower (3 mm) than the irradiation diameter of 8 mm in Example 1, the cracks meandered in the irradiation region 23.

(Comparative Example 2)
As the infrared irradiation device in step 1, using a CO ₂ laser (Coherent GEM-100, beam diameter 4 mm, output 20 W), except that the irradiation region 23 of 8 mm was irradiated from the glass edge on the starting end side of the planned cutting line L, Step 1 was performed in the same manner as in Example 1 to create an initial propagation crack 2b. Although the initial propagation crack 2b occurred in about 6 seconds after the start of irradiation, the initial propagation crack 2b propagated about 20 mm beyond the irradiation region 23 on the planned cutting line L. Further, the crack tip meandered, and the propagation ended when the crack tip finally propagated to the position 3 mm away from the planned cutting line L in the Y direction.

  From the above, it has become clear that the meandering of the initial propagation crack can be suppressed by the present invention. In Comparative Example 1, it was considered that the cracks meandered because the amount of heat during heating was excessively high.

The CO ₂ laser used in Comparative Example 2 has a wavelength of about 10600 nm. Most of the light having this wavelength is absorbed in the vicinity of the irradiation point of the glass base plate and does not transmit in the thickness direction. Although the specific mechanism is unknown, as a result of the absorption as described above, the temperature near the irradiation point rises, and the temperature difference between the irradiation point side surface of the glass base plate and the back surface facing the surface Therefore, it is considered that a compressive stress and a tensile stress different from those of the example were generated in the glass base plate, the crack propagated far beyond the irradiation point, and the tip was meandered. When a CO ₂ laser was used as in Comparative Example 2, the initial propagation crack 2b was formed for a short time, but it became clear that it was difficult to control the propagation direction of the crack.

G: Glass base plate, L: Planned cutting line, 1: Glass edge, 2: Crack, 2a: Initial crack, 2b: Initial propagation crack, 2c: Propagation crack, 2d: Termination crack, 10: End of planned cutting line 10a: start end of planned cutting line, 10b: end of planned cutting line, 20: infrared spot heater, 21: infrared line heater, 22: infrared light, 23: irradiation area, 30: portal frame, 31: support column , 32: bridging rod, 33: slider, 34: rotating part, 35: transport slider, 36: transport rail, 40: mounting table, 41: rotating roll

Claims (8)

In the method of manufacturing a cut glass plate using thermal shock,
Infrared light is irradiated in a dot-like manner on the edge of the glass base plate on the starting end side, and the initial propagation crack is propagated from the glass edge on the start side by the infrared light transmitted through the glass base plate. Step 1 and the initial propagation crack on the planned cutting line or in front of the initial propagating crack are focused and irradiated with infrared light to form a propagating crack that propagates the initial propagating crack along the planned cutting line. Step 2
A method for producing a cut glass sheet, wherein the infrared light irradiation region of step 1 does not include a glass edge on the start end side of a planned cutting line. The method for producing a cut glass sheet according to claim 1, wherein the step 2 is a method in which infrared light is condensed and irradiated using an infrared line heater. 3. The method for producing a cut glass sheet according to claim 1, wherein the irradiation region of the infrared light in the step 1 is on a planned cutting line 1 to 20 mm away from the glass edge on the start end side. The method for producing a cut glass sheet according to any one of claims 1 to 3, wherein the step 1 is a process of performing focused irradiation using an infrared spot heater. The method for producing a cut glass plate according to any one of claims 1 to 3, wherein the step 1 uses a laser that emits light within a wavelength range of 780 to 4000 nm. The method for producing a cut glass sheet according to any one of claims 1 to 5, wherein an initial crack is formed in a glass edge on a start end side on a planned cutting line before the step 1. The thickness of the said glass base plate is 2-25 mm, The manufacturing method of the cut glass plate in any one of the Claims 1 thru | or 6 characterized by the above-mentioned. In a glass base plate cutting device using thermal shock,
The glass base plate installed on the mounting table has an infrared irradiation device at a position where infrared light can be irradiated,
The glass base plate cutting device, wherein the infrared irradiation device is a point irradiation device that irradiates infrared light in a dot shape and an infrared line heater.

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