JPH05116974A - Method and apparatus for production of thin glass sheet - Google Patents

Abstract

PURPOSE:To obtain the thin glass sheet which is free from warpage, wrinkles and reduced width parts and 'has a uniform thickness by heating the glass plate surfaces and the respective side ends by using heaters which are provided with slits and house heat sources in the process for heating and stretching a glass raw plate. CONSTITUTION:The main heater 14 which is provided with the slit 18 and houses the heat source 16 and the auxiliary heaters 20, 22 which are provided with the slits 28, 30 and house the heat sources 24, 26 are prepd. The above- mentioned slit 18 is disposed along the transverse direction of the glass raw plate 10 and the glass raw plate 10 is heated and softened 34 by heat rays. The above-mentioned slits 28, 30 are disposed to face the respective side ends 36, 38 of the glass plate to heat the above-mentioned side ends 36, 38. The thick glass raw plate 10 is stretched under heating, by which the thin glass sheet 12 is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin glass plate manufactured by drawing a thick glass base plate, and more particularly to a redrawing method (remelting method). It has been suppressed.

[0002]

2. Description of the Related Art In order to process a thick glass base plate into a glass thin plate having a desired plate thickness, a method of stretching the glass base plate under heating is adopted.

However, in a method of simply sandwiching a glass base plate with a heater or the like and heating it to stretch it in a softened state, the glass base plate is cooled at a central portion and side end portions thereof after passing through a heating and softening portion. The heat dissipation state is different, and the viscosity at the side end tends to be higher than at the center. When the glass plate is further stretched in this state, a difference in wall thickness occurs, and the wall thickness of the side end portion becomes thicker than that of the central portion.

When the glass plate having a non-uniform thickness is further cooled, the central part having a small thickness is immediately cooled and solidified, but the solidified part at the side end is cooled and solidified more than the central part. Will also be delayed. The glass thin plate thus cooled and solidified has a non-uniform plate thickness, and the shrinkage during cooling varies, causing warpage and wrinkles.

Further, such a warp affects the glass being stretched in the heat-softened portion, and significantly reduces the plate thickness accuracy and flatness of the obtained glass thin plate itself.

In order to suppress the occurrence of such warpage, conventionally,
There is a method of controlling the temperature distribution of the heat-softened portion and increasing the heating temperature of the side end portion of the glass during drawing.

[0007]

However, in the above method, not only the entire manufacturing apparatus becomes huge, but also the heating and softening portion becomes large, so that the shrinkage phenomenon in the width direction of the glass sheet occurs. That is, as shown in FIG. 5, when the glass plate 42 in the heat-softened state is stretched, a reduced width portion 44 is generated in the glass plate. As the heat-softening portion 40 becomes longer, the shrinkage portion 44 becomes larger and the shrinkage a occurs. Further, the formation of the reduced width portion 44 reduces the area of the glass thin plate to be commercialized, resulting in a marked decrease in the manufacturing efficiency of the glass thin plate.

The present invention has been made in order to solve the above-mentioned problems. By shortening the heat-softened portion and eliminating the influence of the thick side edges of the heat-softened glass, warpage and wrinkles are eliminated. It is intended to produce a thin glass plate having a uniform thickness.

[0009]

The method for producing a glass thin plate according to claim 1, wherein the glass thin plate is obtained by stretching a thick glass base plate in a longitudinal direction thereof under heating to obtain a glass thin plate. In the process of heating and stretching the glass base plate fed in the longitudinal direction, using a heating device containing a heat source with a slit, the slit is arranged closely along the width direction of the glass base plate, and from the slit It is characterized in that the glass base plate is heated and softened by the emitted heat rays.

A method of manufacturing a thin glass plate according to claim 2 is
In the method of manufacturing a glass thin plate, which is obtained by stretching a thick glass base plate under heating in the longitudinal direction thereof to obtain a glass thin plate, in the process of heating and extending the glass base plate fed in the longitudinal direction, with a slit. Using a main heating device accommodating a heat source, the slits are arranged close to each other along the width direction of the glass base plate, and the glass base plate is heated and softened by the heat rays emitted from the slits. At least one pair of auxiliary heating devices having slits and containing a heat source are used, and these slits are made to face each side end of the glass plate to heat each side end of the glass plate.

A method of manufacturing a thin glass plate according to claim 3 is
In the method of manufacturing a glass thin plate, which is obtained by stretching a thick glass base plate under heating in the longitudinal direction thereof to obtain a glass thin plate, in the process of heating and extending the glass base plate fed in the longitudinal direction, with a slit. Using a heating device accommodating a heat source, the slits are arranged close to each other along the width direction of the glass base plate, and the glass base plate is heated and softened by the heat rays emitted from the slits. The heating wire is pierced through the glass plate to cut the side ends.

A method of manufacturing a glass sheet according to claim 4 is
In the method of manufacturing a glass thin plate, which is obtained by stretching a thick glass base plate under heating in the longitudinal direction thereof to obtain a glass thin plate, in the process of heating and extending the glass base plate fed in the longitudinal direction, with a slit. Using a heating device accommodating a heat source, the slits are arranged close to each other along the width direction of the glass base plate, and the glass base plate is heated and softened by the heat rays emitted from the slits. Narrow pressure is applied to the side edges of the glass plate with the heating roller.

According to a fifth aspect of the present invention, there is provided a glass thin plate manufacturing apparatus in which a glass plate feeding device heat source is housed and a slit is formed. The slit is opposed to the glass plate in the width direction of the glass plate. A heating device for heating and softening the glass plate is provided with a plate drawing device for drawing the glass plate.

According to a sixth aspect of the present invention, there is provided a glass thin plate manufacturing apparatus for accommodating a heat source for a glass plate feeding device, a slit being formed, and the slit facing the glass plate in the width direction of the glass plate. Main heating device for heating and softening a glass plate A heat source is housed, a slit is formed, and an auxiliary heating device is installed at the side end of the glass plate along the traveling direction of the glass plate behind the main heating device. And a plate drawing device for drawing a glass plate.

According to a seventh aspect of the present invention, there is provided a glass thin plate manufacturing apparatus in which a glass plate feeding device heat source is housed and a slit is formed. The slit is opposed to the glass plate in the width direction of the glass plate. A heating device for heating and softening the glass plate A heating device for melting and cutting a side end portion of the glass plate behind the heating device is provided with a plate drawing device for extending the glass plate.

A glass thin plate manufacturing apparatus according to claim 8 accommodates a glass plate feeding device heat source and is provided with a slit, and the slit is opposed to the glass plate in the width direction of the glass plate. A heating device for heating and softening the glass plate A heating device for narrowing the side end of the glass plate behind the heating device and a plate drawing device for stretching the glass plate are provided.

The glass thin plate manufacturing apparatus according to claim 9 is:
The glass thin plate manufacturing apparatus according to any one of claims 5 to 8, wherein a heating device for heating and softening the glass plate is provided behind the heating device.
It is characterized in that a suppressing plate for suppressing the shake of the glass plate is provided on at least one side of the glass plate.

[0018]

In the method and apparatus for manufacturing a glass thin plate of the present invention, since the glass base plate is heated and softened by using the heating device in which the slit is formed, the glass base plate is heated and softened for a long time. It can be extremely narrow. By narrowing the heat-softened portion, it is possible to suppress the formation of the narrowed portion that occurs in the glass plate.

Further, in the glass plate after being softened by heating, the plate thickness tends to be different between the central part and the side end parts,
The tension due to the nonuniformity of the plate thickness and the warp associated therewith affect the glass plate during heating and softening, but in the present invention, the side end portion of the glass plate after the heating and softening is reheated to make the viscosity uniform. Keeping the temperature at the same time as it is melted and removed immediately By narrowing the pressure with a roller to make the plate thickness uniform, the glass plate during heating and softening is not affected.

[0020]

【Example】

(Example 1) A method for manufacturing a glass thin plate of this example will be described with reference to FIGS. 1 and 2. In order to manufacture the thin glass plate 12, the thick glass base plate 10 is fed from one side by a feeding device, is fed, and is stretched from the other side by a plate pulling device while being heated and softened.

Therefore, in this embodiment, the main heating device 14 is used for heating and softening. As shown in FIGS. 1 and 2, the main heating device 14 is roughly composed of a cylindrical covering wall 15 and a heater wire 16 which is a heat source installed inside the covering wall 15. At least the inner surface of the cover wall 15 is made of a heat-reflecting material having high heat resistance, and forms a heat storage space 17.

Further, it is desirable that the covering wall 15 has a high heat insulating effect, and the inside thereof may be filled with a heat insulating material or may be in a state where air is diluted and sealed.

Further, the cover wall 15 of the main heating device 14 is provided with a slit 18 along the length direction thereof. Although the width of the slit 18 depends on the traveling speed of the glass base plate 10, the thickness of the glass base plate 10 is t, and the width of the slit 18 is t.
If s is set, it is preferable that the following expression is satisfied. t / 10 ≦ ts ≦ 20 × t Therefore, considering that the feeding speed is generally about 200 mm / min, the slit width is preferably about 3 to 6 mm.

Although only one main heating device 14 is shown in FIG. 1 for the sake of convenience, it is more efficient to set a plurality of them so that they face each other with the glass base plate 10 interposed therebetween, as shown in FIG. Not only that, but the quality is also improved.

Further, in this embodiment, the auxiliary heating devices 20 and 22 are used behind the main heating device 14. The auxiliary heating devices 20 and 22 are roughly composed of cylindrical covering walls 21 and 23 and heater wires 24 and 26 installed therein. Similar to the cover wall 15 of the main heating device 14, the cover walls 21 and 23 are made of a heat-reflecting material having at least an inner surface thereof with high heat resistance
The heat storage spaces 25 and 27 are configured. Furthermore, the covering wall 2
It is desirable that 1 and 23 have a high heat insulating effect, and the inside thereof may be filled with a heat insulating material or may be in a state where air is diluted and sealed.

Further, the covering wall 2 of the auxiliary heating devices 20 and 22
1 and 23 have slits 28 and 30 along their length direction.
Are formed. The length of the auxiliary heating devices 20 and 22 depends on the feeding speed of the glass plate, but the feeding speed is 200 mm / min.
If it is a degree, about 200 mm is preferable.

Then, as shown in FIG. 1, the side ends 36 and 38 of the glass plate are fitted into the slits 28 and 30 of the auxiliary heating devices 20 and 22 facing each other, and only the side ends 36 and 38 are heated. To do. If only the side edges 36 and 38 of the glass plate are heated, it is not necessary for the side edges 36 and 38 of the glass plate to pass between the slits 28 and 30, and the auxiliary heating devices 20 and 22 are It suffices if it is provided close to the side end portions 36 and 38 of the plate.

In FIGS. 1 and 2, the main heating device 14
The auxiliary heating devices 20 and 22 have a cylindrical shape, but may have a triangular prism shape or a rectangular parallelepiped shape.

As the glass plate feeding device and the plate drawing device, devices generally used in the past can be applied.

In the method for manufacturing a glass thin plate of this embodiment, the glass base plate 10 to be fed is first heated and softened by the main heating device 14. The heat from the main heating device 14 is the main heating device 1
The glass base plate 1 only from the slit 18 formed in 4.
Since it is added to 0, the length of the heat softening portion 34 can be made extremely narrow. Therefore, the shrinkage in the width direction of the glass sheet, which occurs in the conventional method in which the heat-softened portion is wide (see FIG. 5).
A) can be suppressed. Therefore, the warp and wrinkles of the glass plate can be suppressed, and the quality can be improved. Moreover, since it does not shrink in the width direction, the area of the glass thin plate obtained as a product can be significantly increased, and the efficiency is high.

Further, although the slit 18 has a narrow width, a heat storage space 17 is formed inside the main heating device 14, and sufficient heat from the heat storage space 17 is provided in the slit 1.
Since it is intensively emitted from the glass plate 8, even if the width of the slit 18 is narrow, it is sufficient to heat and soften the glass base plate 10. In addition, when softening by heating, the viscosity of the glass plate is 10 ⁴
Well if about 10 ⁷ poise, the temperature of the main heater 14 may be the temperature at which the glass sheet is equal to or higher than the softening point.

After the glass plate is further softened by heating, the side ends 36 and 38 of the auxiliary heating devices 20 and 22 are intensively heated. By intensively heating the side edges 36 and 38 of the glass plate, there is no influence on the glass plate of the heating and softening part, and the plate thickness accuracy and flatness of the glass plate can be improved. .. Incidentally, the auxiliary heating devices 20, 22
The temperature is preferably between the glass transition temperature of the glass plate used and the annealing point.

The side edges 36 and 38 of the glass sheet 12 that has been completely cooled and solidified are cut and removed in a rear process of the manufacturing process to be commercialized.

The main heating device 14 and the auxiliary heating device 2
By providing the restraint plate 32 between 0 and 22 to suppress the shake of the glass plate, it is possible to manufacture the glass thin plate 12 that is more stable and smooth. The restraint plate 32 is preferably made of mica or the like as a spring material and graphite foil or the like on the contact side with the glass plate. Further, even if it is not a plate-shaped member but a roller-shaped member, a sufficient effect can be obtained. it can.

In the method and manufacturing apparatus of this embodiment, the heating and softening part is extremely small and the auxiliary heating device 2
Since 0 and 22 are also small, the size of the glass thin plate manufacturing apparatus itself can be extremely reduced as a whole. Further, the structure itself can be simplified.

Further, by providing a slow cooling device capable of uniformly cooling the entire glass plate behind the auxiliary heating devices 20 and 22, it is possible to manufacture a glass sheet with higher accuracy.

In the method and manufacturing apparatus of the present invention,
Since an extremely thin glass plate having a thickness of 20 μm can be accurately manufactured with high smoothness, it can be applied to, for example, a gap plate of a magnetic head of a video deck or an audio system, a spacer for dividing a channel, or the like.

(Embodiment 2) A method and an apparatus for manufacturing a glass thin plate according to Embodiment 2 will be described with reference to FIGS. 2 and 3.
The glass thin plate manufacturing method of this embodiment is characterized by using a main heating device and a heating wire, but the main heating device of the first embodiment can be directly applied to the main heating device.

Therefore, like the first embodiment, in order to manufacture the thin glass plate 12, the thick glass base plate 10 is fed from one side by the feeding device and is fed, and the plate is drawn in the state of being heated and softened. The device stretches from the other. Then, also in this embodiment, as in the first embodiment, the main heating device 14 is used for heating and softening. As shown in FIGS. 2 and 3, the main heating device 14 is roughly composed of a cylindrical covering wall 15 and a heater wire 16 installed inside the covering wall 15. At least the inner surface of the cover wall 15 is made of a heat-reflecting material having high heat resistance, and forms a heat storage space 17.

Furthermore, it is desirable that the cover wall 15 has a high heat insulating effect, and the inside thereof may be filled with a heat insulating material, or may be in a state where air is diluted and sealed.

Further, a slit 18 is formed in the cover wall 15 of the main heating device 14 along the length direction thereof. The width of the slit 18 depends on the traveling speed of the glass base plate 10, but if the plate thickness of the glass base plate 10 is t and the width of the slit is ts, it is preferable that the relationship satisfy the following equation. .. t / 10 ≦ ts ≦ 20 × t Therefore, considering that the feeding speed is generally about 200 mm / min, the slit width is preferably about 3 to 6 mm.

Although only one main heating device 14 is shown in FIG. 3 for the sake of convenience, it is more efficient to set a plurality of them so as to face each other with the glass base plate 10 interposed therebetween, as shown in FIG. Not only that, but the quality is also improved.

Further, in this embodiment, the heating wires 46, 46 are used behind the main heating device 14. The heating wires 46, 46 generate heat when energized, and are used in a state in which they generate heat above the glass softening temperature.

Then, the heating wires 46, 46 are pierced through the side ends of the glass plate, and the side ends 36, 38 of the glass plate are melted and removed by feeding the glass plate.

In the method for manufacturing a thin glass plate of this embodiment, the glass base plate 10 to be fed is first heated and softened by the main heating device 14. The heat from the main heating device 14 is the main heating device 1
The glass base plate 1 only from the slit 18 formed in 4.
4, the length of the heating and softening portion 34 can be made extremely narrow. Therefore, the shrinkage in the width direction of the glass sheet, which occurs in the conventional method in which the heat-softened portion is wide (see FIG. 5).
A) can be suppressed. Therefore, the warp and wrinkles of the glass plate can be suppressed, and the quality can be improved. Moreover, since it does not shrink in the width direction, the area of the glass thin plate obtained as a product can be significantly increased, and the efficiency is high.

Further, although the slit 18 has a narrow width, a heat storage space 17 is formed inside the main heating device 14, and sufficient heat from the heat storage space 17 is provided in the slit 1.
Since it is intensively emitted from the glass plate 8, even if the width of the slit 18 is narrow, it is sufficient to heat and soften the glass base plate 10. In addition, when softening by heating, the viscosity of the glass plate is 10 ⁴
Well if about 10 ⁷ poise, the temperature of the main heater 14 may be the temperature at which the glass sheet is equal to or higher than the softening point.

Further, the glass plate after being softened by heating is
The side ends 36 and 38 of the heating wires 46 and 46 are fused and removed. Immediate removal of the side edges 36 and 38 of the glass plate having a different thickness from the central part of the glass plate eliminates the influence on the glass plate of the heating and softening part,
The plate thickness accuracy and flatness of the glass plate can be improved.

Further, as in the first embodiment, a restraint plate is provided between the main heating device 14 and the heating wires 46, 46 to suppress the shake of the glass plate, thereby making the glass thin plate 1 more stable and smooth.
2 can be manufactured. The deterrent board uses mica as a spring material,
It is desirable to use a graphite foil or the like on the contact side with the glass plate, and it is possible to obtain a sufficient effect even if it is not a plate shape but a roller shape.

In the method and manufacturing apparatus of this embodiment, the heating and softening portion is extremely small and the heating wire 4
Since 6 and 46 are also small, the size of the glass thin plate manufacturing apparatus itself can be extremely reduced as a whole. Further, the structure itself can be simplified.

According to the method of the present invention, an extremely thin glass plate having a thickness of 10 to 20 μm can be accurately manufactured with high smoothness, so that it is applied to, for example, a gap plate of a magnetic head of a video deck, an audio system or a spacer for channel division. be able to.

Even if this heating wire 46 is applied in the method for manufacturing a glass thin plate of the first embodiment, that is, the heating wire 46 is provided behind the auxiliary heating device of the first embodiment so that the side end portion of the glass thin plate is located. Of course, it does not matter even if it is melted and removed.

(Embodiment 3) A method and an apparatus for manufacturing a glass thin plate of Embodiment 3 will be described with reference to FIGS. 2 and 4.
The glass thin plate manufacturing method and manufacturing apparatus of this embodiment are characterized in that a main heating device and a heating roller are used, and the main heating device of the first embodiment can be directly applied to the main heating device. Therefore, in the same manner as in Example 1, in order to manufacture the thin glass plate 12, the thick glass base plate 10 is fed from one side by the feeding device, and this is fed to the plate drawing device while being heated and softened. And extend from the other. Also in this embodiment, the main heating device 14 is used for softening by heating as in the first embodiment.

As shown in FIGS. 2 and 4, the main heating device 14 is roughly composed of a cylindrical covering wall 15 and a heater wire 16 installed inside the covering wall 15. At least the inner surface of the cover wall 15 is made of a heat-reflecting material having high heat resistance, and the heat storage space 1
Make up 7. Furthermore, it is desirable that the cover wall 15 has a high heat insulating effect, and the inside thereof may be filled with a heat insulating material, or may be in a state where air is diluted and sealed.

Further, a slit 18 is formed in the cover wall 15 of the main heating device 14 along the length direction thereof. The width of the slit 18 depends on the traveling speed of the glass base plate 10, but if the plate thickness of the glass base plate 10 is t and the width of the slit is ts, it is preferable that the relationship satisfy the following equation. .. t / 10 ≦ ts ≦ 20 × t Therefore, considering that the feeding speed is generally about 200 mm / min, the slit width is preferably about 3 to 6 mm.

Although only one main heating device 14 is shown in FIG. 4 for the sake of convenience, it is only efficient to set a plurality of main heating devices 14 so as to face each other with the glass base plate 10 interposed therebetween, as shown in FIG. Not only that, but the quality is also improved.

Further, in this embodiment, heating rollers 48, 48, 48, 48 are used behind the main heating device 14. The heating roller 48 itself generates heat, and the side end portion 3 of the glass plate 3
The pressure of 6, 38 is narrowed.

In the method for manufacturing a glass thin plate of this embodiment, the glass base plate 10 to be fed is first heated and softened by the main heating device 14. The heat from the main heating device 14 is the main heating device 1
The glass base plate 1 only from the slit 18 formed in 4.
4, the length of the heating and softening portion 34 can be made extremely narrow. Therefore, the shrinkage in the width direction of the glass sheet, which occurs in the conventional method in which the heat-softened portion is wide (see FIG. 5).
A) can be suppressed. Therefore, the warp and wrinkles of the glass plate can be suppressed, and the quality can be improved. Moreover, since it does not shrink in the width direction, the area of the glass thin plate obtained as a product can be significantly increased, and the efficiency is high.

Although the slit 18 has a narrow width, a heat storage space 17 is formed inside the main heating device 14, and sufficient heat from the heat storage space 17 is provided in the slit 1.
Since it is intensively emitted from the glass plate 8, even if the width of the slit 18 is narrow, it is sufficient to heat and soften the glass base plate 10. In addition, when softening by heating, the viscosity of the glass plate is 10 ⁴
Well if about 10 ⁷ poise, the temperature of the main heater 14 may be the temperature at which the glass sheet is equal to or higher than the softening point.

The heat-softened glass plate is immediately narrowed by the heating rollers 48, 48, 48, 48 to make the side edges 36, 38 of the glass plate uniform in thickness with the central part. By making the thickness of the glass plate uniform, there is no influence on the glass plate of the heating and softening part, and the plate thickness accuracy and flatness of the glass plate can be improved. The temperature of the heating roller 48 is preferably equal to or higher than the glass softening point temperature of the glass plate to be used, but even if the temperature is lower than that, it is possible to make the plate thickness uniform by increasing the narrow pressure. However, increasing the narrow pressure at a low temperature increases the risk of cracks and the like on the glass plate, which is not preferable.

The side edges 36 and 38 of the glass sheet 12 which has been completely cooled and solidified are cut and removed in a rear process of the manufacturing process to be commercialized. At this time, it goes without saying that the heating wire used in Example 2 can be applied.

Further, similarly to the first embodiment, by providing a restraining plate between the main heating device 14 and the heating roller 48 to suppress the shake of the glass plate, it is possible to manufacture the glass thin plate 12 that is more stable and smooth. .. The restraint plate is preferably made of mica or the like as a spring material, and a graphite foil or the like is used on the contact side with the glass plate. Also, it is possible to obtain a sufficient effect even if it is not a plate shape but a roller shape. it can.

In the method and manufacturing apparatus of this embodiment, since the heating and softening portion is extremely small and the heating roller 48 is also small, the size of the glass sheet manufacturing apparatus itself can be made extremely small as a whole. .. Further, the structure itself can be simplified.

According to the method of the present invention, an extremely thin glass plate having a thickness of 10 to 20 μm can be manufactured with high precision and high accuracy, and therefore, it is applied to, for example, a gap plate of a magnetic head of a video deck, an audio system, a spacer for dividing a channel, or the like. be able to.

[0064]

EFFECT OF THE INVENTION In the method for producing a glass thin plate by heating and softening a glass base plate and stretching it, when the heat-softened portion becomes long, the glass plate shrinks in the width direction and a reduced width portion is formed. .. Further, the glass plate after being softened by heating has a non-uniform plate thickness caused by a difference in cooling rate, which causes the glass plate to warp. The tension caused by this warp affects the glass plate during heating and softening, and significantly deteriorates the plate thickness accuracy and flatness of the glass plate.

Therefore, in the method for manufacturing a glass sheet according to claim 1 or the apparatus for manufacturing a glass sheet according to claim 5, a heating device having slits is used for heating and softening the glass plate. .. Since the glass base plate is intensively heated from the slit having a narrow width, the heating and softening portion is short, and it is difficult for the glass plate to shrink in the width direction. Therefore, the warp and wrinkles of the thin glass plate can be suppressed, and the quality can be improved. In addition, since the reduced width portion is not formed, the production efficiency can be improved. Further, since the heat storage space is formed inside the heating device, the heating efficiency is good and a sufficient heating action can be exhibited.

Further, in the method for manufacturing a glass thin plate according to the second aspect or the manufacturing apparatus according to the sixth aspect, a main heating device having a slit is used for heating and softening the glass plate. Since the glass base plate is intensively heated from the slit having a narrow width, the heating and softening portion is short, and it is difficult for the glass plate to shrink in the width direction. Therefore, the warp and wrinkles of the thin glass plate can be suppressed, and the quality can be improved. In addition, since the reduced width portion is not formed, the production efficiency can be improved. Further, since the heat storage space is formed inside the main heating device, thermal efficiency is good and a sufficient heating action can be exhibited.

Furthermore, the auxiliary heating device is used behind the main heating device to heat only the side end portions of the glass plate to adjust the cooling conditions of the glass plate after heating and softening to suppress the occurrence of warpage. Therefore, the influence on the glass plate during heating and softening is stopped. Therefore, it is possible to more stably manufacture a high-quality glass thin plate having high flatness and free from wrinkles and warpage.

Further, in the manufacturing method according to the third aspect or the manufacturing apparatus according to the seventh aspect, the heating device in which the slit is formed is also used for heating and softening the glass plate. Since the glass base plate is intensively heated from the slit having a narrow width, the heating and softening portion is short, and it is difficult for the glass plate to shrink in the width direction. Therefore, the warp and wrinkles of the thin glass plate can be suppressed, and the quality can be improved.
In addition, since the reduced width portion is not formed, the production efficiency can be improved. Further, since the heat storage space is formed inside the heating device, the heating efficiency is good and a sufficient heating action can be exhibited.

Then, a heating wire is used behind the heating device. By fusing and removing only the side edges of the glass sheet with a heating wire, the influence of the side edges of the glass sheets having different wall thicknesses on the glass sheet being heated and softened is limited. Therefore, it is possible to more stably manufacture a high-quality glass thin plate having high flatness and free from wrinkles and warpage.

Furthermore, in the manufacturing method according to claim 4 or the manufacturing apparatus according to claim 8, in heating and softening the glass plate,
A heating device having slits is also used. Since the glass base plate is intensively heated from the slit having a narrow width, the heating and softening portion is short, and it is difficult for the glass plate to shrink in the width direction. Therefore, the warp and wrinkles of the thin glass plate can be suppressed, and the quality can be improved. In addition, since the reduced width portion is not formed, the production efficiency can be improved. Further, since the heat storage space is formed inside the heating device, the heating efficiency is good and a sufficient heating action can be exhibited.

A heating roller is used behind the heating device. By the heating roller, the side edges of the glass plate are narrowed to eliminate the unevenness of the plate thickness of the glass plate after heating and softening, and thus the adverse effect on the glass plate during heating and softening can be avoided. .. Therefore, it is possible to more stably manufacture a high-quality glass thin plate having high flatness and free from wrinkles and warpage.

Further, in addition to the above-mentioned invention, the apparatus for manufacturing a glass thin plate according to a ninth aspect of the present invention suppresses the shake of the glass plate by the restraint plate immediately after the glass plate is heated and softened. By suppressing the shake of the glass sheet, it becomes possible to stably produce a glass sheet having a significantly smooth surface.

[Brief description of drawings]

FIG. 1 is a perspective view showing a method for manufacturing a glass thin plate according to a first embodiment.

FIG. 2 is a side cross-sectional view of a peripheral portion of a main heating device in a method for manufacturing a glass thin plate according to Examples 1 to 3.

FIG. 3 is a perspective view illustrating a method for manufacturing a glass thin plate according to a second embodiment.

FIG. 4 is a perspective view showing a method for manufacturing a thin glass plate of Example 3.

FIG. 5 is a perspective view showing a reduced width portion that occurs in a conventional method for manufacturing a thin glass plate.

[Explanation of symbols]

 10 Glass base plate 12 Glass thin plate 14 Main heating device 16 Heater wire 18 Slit 20 Auxiliary heating device 22 Auxiliary heating device 24 Heater wire 26 Heater wire 28 Slit 30 Slit 32 Suppression plate 34 Heat softening part 36 Side end 38 side Edge part 40 Heat softening part 42 Glass plate 44 Reduction width part 46 Heating wire 48 Heating roller

Claims (9)

[Claims] 1. A method for manufacturing a thin glass plate, wherein a glass thin plate is obtained by stretching a thick glass base plate in a longitudinal direction while heating the glass base plate, wherein the glass base plate fed in the longitudinal direction is heated and stretched. In, using a heating device containing a heat source with a slit, the slit is arranged in proximity along the width direction of the glass base plate, characterized by heating and softening the glass base plate by the heat rays emitted from the slit. A method for manufacturing a thin glass plate. 2. A method for manufacturing a thin glass plate, which comprises obtaining a thin glass plate by heating a thick glass base plate in the longitudinal direction while heating the glass base plate, and heating and extending the glass base plate fed in the longitudinal direction. In, using a main heating device containing a heat source with a slit, the slits are arranged close to each other along the width direction of the glass base plate, and the glass base plate is heated and softened by the heat rays emitted from the slit, and further, At least a pair of auxiliary heating devices having a slit and containing a heat source are used, and each side end of the glass plate is heated by making these slits face each side end of the glass plate. .. 3. A method for manufacturing a thin glass plate, wherein a thin glass plate is obtained by stretching a thick glass base plate in the longitudinal direction under heating, in the method of heating and stretching the glass base plate fed in the longitudinal direction. With a heating device containing a heat source with a slit, the slit is arranged closely along the width direction of the glass base plate, and the glass base plate is heated and softened by the heat rays emitted from the slit, and further heated. A method for producing a thin glass plate, characterized in that a wire is pierced through the glass plate to melt the side edges. 4. A method for manufacturing a thin glass plate, which comprises obtaining a thin glass plate by heating a thick glass base plate in the longitudinal direction while heating the glass base plate, and heating and extending the glass base plate fed in the longitudinal direction. With a heating device containing a heat source with a slit, the slit is arranged closely along the width direction of the glass base plate, and the glass base plate is heated and softened by the heat rays emitted from the slit, and further heated. A method for producing a thin glass plate, characterized in that a roller is used to narrow the side edges of the glass plate. 5. A heating device for accommodating a heat source and having a slit formed therein, wherein the slit faces the glass plate in the width direction of the glass plate to heat and soften the glass plate, and a glass plate feeding device. An apparatus for manufacturing a thin glass plate, comprising: a glass plate; and a plate drawing device for stretching the glass plate. 6. A main heating device for accommodating a heat source and having a slit formed therein, wherein the slit faces the glass plate in the width direction of the glass plate to heat and soften the glass plate, and the heat source is accommodated, A slit is formed and behind the main heating device, an auxiliary heating device is installed at the side edge of the glass plate along the direction of travel of the glass plate, a glass plate feeding device, and the glass plate is stretched. An apparatus for manufacturing a thin glass plate, comprising: a drawing device. 7. A heating device for accommodating a heat source and having a slit formed therein, the heating device for heating and softening the glass plate by facing the slit in the width direction of the glass plate to face the glass plate, and behind the heating device. An apparatus for manufacturing a thin glass plate, comprising: a heating wire that melts and cuts a side end portion of the glass plate; a glass plate feeding device; and a plate drawing device that extends the glass plate. 8. A heating device for accommodating a heat source and having a slit, wherein the slit faces the glass plate in the width direction of the glass plate and heats and softens the glass plate, and behind the heating device, An apparatus for manufacturing a thin glass plate, comprising: a heating roller for narrowing a side end portion of the glass plate; a feeding device for the glass plate; and a plate drawing device for stretching the glass plate. 9. The glass thin plate manufacturing apparatus according to claim 5, wherein a suppressing plate for suppressing shake of the glass plate is provided at least on one side of the glass plate behind the heating device for heating and softening the glass plate. An apparatus for manufacturing a thin glass plate, which is provided.