JPH0585765A - Method for breaking glass plate - Google Patents

Abstract

PURPOSE:To accurately break even an especially thick glass plate. CONSTITUTION:The line 3 parts of a glass plate 1 are cooled by jetting a refrigerant on the lines 3 from first nozzles 5. Parts at the outsides of the lines 3 are then pressed down with pressing rolls 7 while lifting the line 3 parts from the bottoms with receiving rolls 6 and pressing force (bending moment) is applied in a direction in which the lines 3 are enlarged to break the glass plate 1 along the lines 3. Even an especially thick glass plate can be accurately broken along lines.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaving thick glass sheets, and more particularly to a method suitable for cleaving extra thick glass sheets having a sheet thickness of about 15 to 19 mm or more.

[0002]

2. Description of the Related Art Conventionally, in order to produce a thick glass plate having a standard size, a glass ribbon is slowly pulled up from the inside of a glass tank kiln, then cut into a predetermined length, and then both sides of the thick glass plate are cut. Cleave (ear).

In order to cut the ears, a cut-like streak is inserted by a trimmer, and then a pressing force (bending moment) in the direction of expanding the streak is applied to break the thick glass plate.
In order to apply this pressing force, the thick glass plate in a horizontal position and having a streak on the upper surface is pushed upward by a roller from the lower surface side. In addition, when a larger split pressing force (bending moment) is required, the thick glass plate edge side is further pressed from above by a pressing roller from above.

[0004]

When the plate thickness of the thick glass plate becomes extremely large, it is often the case that the above conventional method does not cut along the lines. Moreover, the cut edges of the cut thick glass plate are often uneven.

[0005]

A method for cleaving a thick glass plate according to claim 1 of the present invention is to provide a cut glass-like streak on the thick glass plate,
Next, in a method of cutting a thick glass plate in which the streak glass plate is cut along the streak by pressing the streak in a direction in which the streak is widened, the streak portion is cooled by a refrigerant after the streak is attached It is a thing.

A method of cleaving a thick glass plate according to a second aspect is the method of cleaving a thick glass plate according to the first aspect, characterized in that the refrigerant is liquid nitrogen or alcohol dry ice.

[0007]

The thick glass plate gradually pulled up from the glass tank kiln is in a temperature state of several tens of degrees Celsius (for example, 50 to 60 degrees Celsius). After streaking the thick glass plate in this warm state,
When the portion of the muscle is cooled with a refrigerant, tensile stress is locally generated in the portion of the muscle. Therefore, by applying a pressing force in the direction in which the muscle is widened, it is possible to cleanly cut along the muscle.

If liquid nitrogen or alcohol dry ice is used as the refrigerant, the thick glass plate can be efficiently cooled.

[0009]

EXAMPLE FIG. 1 is a perspective view showing an example method. Thick glass plate 1 pulled out from a glass tank kiln (not shown)
After being cut to a predetermined length, it is conveyed on the roller group 2 in a horizontal posture. A first streak (cutter line) 3 and a second streak (cutter line) along the side of the thick glass plate 1 on the roller group 2
Insert 4. The second streak 4 is located closer to the center of the thick glass plate 1 than the first streak 3.

First, a refrigerant (liquid nitrogen in this embodiment) is jetted from the first nozzle 5 to the first streak 3 to cause the streak 3 to move.
To cool the part. Next, the receiving roller 6 lifts the portion of the streak 3 from below, and the portion closer to the side end than the streak 3 is pushed down by the pressing roller 7, and a pressing force (bending moment) is applied in the direction to spread the streak 3. , Cut the thick glass plate along the streaks 3.

After that, the refrigerant is jetted from the second nozzle 8 toward the second streak 4 to cool the portion of the second streak 4.

Next, the receiving roller 9 lifts up the portion of the streak 4 from below, and the portion closer to the side end than the streak 4 is pushed down by the pressing roller 10 to push the streak 4 in a direction to spread it (bending moment). ) Is added, and the thick glass plate is cut along the streak 4.

The receiving rollers 6 and 9 and the pressing rollers 7 and 10
Are vertically stroked by about 10 mm by cylinders 6a, 9a, 7a and 10a, respectively. The operation of this cylinder is preferably controlled based on a detection signal of a sensor (for example, a limit switch) that detects the thick glass plate.

Reference numeral 11 is a pipe for sending liquid nitrogen to the nozzles 5 and 8. The degree of cooling of the thick glass plate 1 can be adjusted by controlling the supply amount of this liquid nitrogen. Further, in order to locally and efficiently cool only the portions of the streaks 3 and 4, it is preferable that the heights of the lower ends of the nozzles 5 and 8 from the thick glass plate 1 be about 25 to 50 mm. As shown in FIG. 2, the nozzles 5 and 8 are inclined to the upstream side in the traveling direction of the thick glass plate 1 by about 1 to 15 °, and the nozzles 5 and 8 are
It is preferable that the liquid nitrogen hitting the thick glass plate 1 ejected from the glass is scattered downstream in the traveling direction to uniformly cool the portions along the streaks 3 and 4.

In the present invention, the nozzles 5, 8 and the rollers 6, 7,
It is preferable that 9 and 10 can be moved in the width direction of the thick glass plate by an appropriate mechanism such as a ball screw so as to be able to follow changes in the dimensions of the thick glass plate.

In the above embodiment, the receiving rollers 6 and 9 are
It is preferable to dispose them about 0 to 25 mm inward from the muscles 3 and 4, respectively. It is preferable that the pressing rollers 7 and 10 are arranged outside the lines 3 and 4 by about 25 to 50 mm.

In the present invention, as described above, it is preferable that the portions of the streaks 3 and 4 are cooled by the coolant and then immediately cut.
This is because, after a certain period of time has passed after cooling, the heat of the thick glass plate causes the cooled portion to reheat.

Although the pressing rollers 7 and 10 are used in the above embodiment, only the receiving rollers 6 and 9 may be used in the present invention. However, when the extra thick glass plate is cut, it is preferable to use a pressing roller.

[0019]

As described above, according to the method for cleaving a thick glass plate of the present invention, even a thick glass plate having a large thickness can be accurately cleaved along the streaks. In addition, claim 2
According to the method for cleaving the thick glass plate, the streak portion can be efficiently cooled.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating an example method.

FIG. 2 is a side view of a nozzle.

[Explanation of symbols]

 1 Thick glass plate 3, 4 Streak 5, 8 Nozzle 6, 9 Receiving roller 7, 10 Pressing roller 11 Piping

Claims (2)

[Claims] 1. A method for cleaving a thick glass plate in which a cut-like streak is attached to a thick glass plate, and then the streak is cut along the streak by pressing in a direction to spread the streak. After that, the method for cleaving a thick glass plate is characterized in that the streaks are cooled with a refrigerant. 2. The method for cleaving a thick glass plate according to claim 1, wherein the refrigerant is liquid nitrogen or alcohol dry ice.