JPH02149437A - Glass plate production device - Google Patents

Abstract

PURPOSE:To obtain the glass plate which has uniform thickness and small contraction in the lateral direction by combining the furnace wall with a forming body so as to have specified action and providing a horizontal partition wall separating the furnace chamber into an upper chamber and a lower chamber under the forming body CONSTITUTION:A molten glass supply pipe horizontally disposed is connected with the recessed part 2a of the forming body 2. The molten glass 3 supplied to the recessed part 2a from the molten glass supply pipe is overflowed from a slit type opening of the recessed part 2a, flowed down along both side surface of the forming body 2, and joined together at the lower end part of the forming body 2. The confluent molten glass 3 is cooled into glass plate 3' and pulled down by a pair of tension rollers 4 rovolvingly driven. The forming atmosphere 6a is allowed to controlled in high temp., and the cooling atmosphere 6b to be controlled in low temp. As a result, the molten glass 3 is flowed in a uniform thickness along the forming body 2, and the glass body 3' is made in the uniform thickness, and the formed glass plate 3' is cooled to be solidified which restrains the lateral contraction due to surface tension.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a glass plate manufacturing apparatus, and more particularly to a glass plate manufacturing apparatus that pulls out a glass plate vertically downward.

[Conventional technology]

As a method for manufacturing a glass plate, a down-draw manufacturing method is known in which the glass plate is pulled vertically downward (see, for example, Japanese Patent Application Laid-Open No. 11235/1983). A glass plate is produced by flowing down along both sides of the molded body, merging at the lower end of the molded body, and pulling it out downward while cooling.

The molded body is placed above the furnace chamber surrounded by a refractory brick furnace wall, and below the molded body on the white lower side of the furnace chamber is a cooling atmosphere that cools the glass plate after molding. ing.

[Problem that the invention seeks to solve]

In the case of the glass plate manufacturing method using the above method, the molding atmosphere near the molded body above the furnace chamber needs to be kept at a relatively high temperature so that the molten glass flows along the molded body with a uniform thickness. Also, the temperature of the lower cooling atmosphere needs to be set to a relatively low value so as to cool the formed glass plate as quickly as possible. This is because, if this is not done, the glass will remain in a low viscosity state even after molding, and the molded glass will shrink in the width direction due to the surface tension of the glass.

However, in the case of conventional glass manufacturing equipment, as described above, it is extremely difficult to separately optimally control the temperatures of the molding atmosphere and the cooling atmosphere that exist in one furnace chamber. Therefore, the thickness of the molten glass and, by extension, the thickness of the glass plate are not uniform, and shrinkage occurs in the width direction.

Furthermore, due to the inflow of low-temperature air from outside the furnace chamber and the temperature difference in the air in the cooling atmosphere, convection is generated inside the furnace chamber, but this convection reaches the molding atmosphere and causes damage to the molded product. The temperature of the molten glass flowing down along the glass plate becomes uneven, causing uneven thickness on the glass plate.

The present invention has been made in order to eliminate the above-mentioned problems and drawbacks, and its purpose is to make the thickness of the manufactured glass sheets uniform, to reduce the shrinkage in the width direction, and to make the thickness of each glass sheet uniform. To provide a glass plate manufacturing device capable of suppressing wall thickness unevenness.

[Means for solving problems]

In order to achieve the above object, the present invention includes a furnace wall forming a furnace chamber, and a molded body having a substantially wedge-shaped cross section for forming molten glass into a plate shape, which is placed above the furnace chamber. A glass plate manufacturing apparatus for pulling out the glass plate downward while cooling the glass plate, characterized in that a substantially horizontal partition wall is disposed immediately below the molded body to separate the furnace chamber into an upper chamber and a lower chamber. There is.

It is preferable that the partition walls are horizontally movably arranged on both sides of the glass plate, and that the ends of the partition walls facing each other are close to the glass plate.

[Effect]

The partition wall placed directly below the molded object separates the molding atmosphere for the glass plate from the cooling atmosphere to prevent the two atmospheres from influencing each other and to optimally control the temperature of both atmospheres individually. enable.

〔Example〕

Next, the present invention will be explained in detail based on the embodiment shown in the drawings.

The figure schematically shows a vertical cross section of a glass plate manufacturing apparatus.The shown molded body 2 is a so-called feeding cell having a recess 2a for accommodating a molten glass 3, but other types (e.g. (described in Japanese Utility Model Publication No. 6221034) may also be used. A molten glass supply pipe (not shown) is connected to the recess 2a of the molded body 2, which is arranged horizontally in the front-rear direction of the drawing. From this molten glass supply pipe to the recess 2
The molten glass 3 supplied to the molten glass 3 overflows from the slit-shaped opening above the recess 2a, flows down along both side surfaces of the molded body 2, and merges at the lower end of the molded body 2. Merged molten glass 3
is cooled to form a glass plate 3', which is pulled downward by a pair of rotationally driven pulling rollers 4. In order to control the temperature of the molten glass 3 or the glass plate 3', a heating device, a water cooling plate, etc. (not shown) are provided at appropriate positions within the furnace wall 1.

Immediately below the molded body 2, there are partition walls 5a and 5b with excellent heat insulation properties.
are arranged horizontally, and the furnace chamber surrounded by the furnace wall 1 is separated by the partition walls 5a and 5b into two upper and lower chambers 6a and 6b. Partition wall 5a.

5b can be moved horizontally as indicated by the arrow manually or by a suitable operating device, and this horizontal movement places the partitions 5a, 5b as close as possible to the glass plate 3' from both sides of the glass TFI 3'. has been done. Note that the shapes of the tips of the partition walls 5a and 5b have a large influence on the thickness distribution of the glass plate 3', so they are required to have sufficient smoothness in the width direction (front-to-back direction in the figure).

As the material for the partition walls 5a and 5b, a material with good heat insulation properties, such as a ceramic fiber plate, is used.

The partition wall 5a5b arranged immediately below the molded body 2 separates the molding atmosphere (upper chamber 6a) of the glass plate 3' from the cooling atmosphere (lower chamber 6b) to prevent the two atmospheres from influencing each other. At the same time, it enables individual and optimal temperature control of both atmospheres.

Therefore, since the temperature of the molding atmosphere 6a can be controlled to a high temperature and the temperature of the cooling atmosphere 6b can be controlled to a low temperature, the molten glass 3 flows along the molded body 2 with a uniform thickness, and the thickness of the glass body 3' becomes uniform, and the formed glass plate 3
' is quickly cooled and solidified in the cooling atmosphere 6b, and shrinkage in the width direction due to surface tension can be suppressed.

Further, even if convection occurs in the cooling atmosphere 6b due to the inflow of low-temperature air from outside the furnace chamber, the temperature difference between the air in the cooling atmosphere, etc., this convection is almost blocked by the partition walls 5a and 5b. It hardly affects the molding atmosphere 6a. Therefore, since there is little temperature difference in the molten glass 3 due to convection, the viscosity is kept uniform and a good fluidity state of the molten glass 3 is maintained, thereby suppressing unevenness in the thickness of the individual glass plates 3'. Can be done.

When ceramic fiber partition walls 5a and 5b with a thickness of 251 mm were installed 30 mm below the lower end of the molded body 2 using the above glass plate manufacturing apparatus, the maximum molding width of the glass plate 3' was 320 mm compared to the conventional case. The width of the uniformly thick part, excluding the thick "lugs" at both ends in the width direction, has been increased from 200mm to 300mm.

〔Effect of the invention〕

As explained above, the present invention separates the molding atmosphere of the glass plate from the cooling atmosphere by disposing the partition immediately below the molded body, so that the two atmospheres can be prevented from influencing each other. The temperature of both atmospheres can be individually and optimally controlled. Therefore, the width of the uniformly thick portion of the glass plate can be increased, the thickness of all the manufactured glass plates can be made uniform, and the unevenness in the thickness of each glass plate can be suppressed.

[Brief explanation of the drawing]

The figure is a schematic vertical sectional view of a glass plate manufacturing apparatus according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Furnace wall, 2... Molded object, 2a... Recessed part,
3... Molten glass, 3'... Glass plate,
4... Tension roller, 5a, 5b... Partition wall,
6a...Upper chamber (molding atmosphere), 6b...Lower chamber (molding atmosphere) Applicant Hoya Co., Ltd. Agent Patent attorney Shizuo Nakamura

Claims (1)

[Scope of Claims] 1. A furnace wall forming a furnace chamber, and a molded body having a substantially wedge-shaped cross section for forming molten glass into a plate shape, disposed above the furnace chamber, A glass plate manufacturing apparatus for pulling out the glass plate downward while cooling the glass plate, characterized in that a substantially horizontal partition wall that separates a furnace chamber into an upper chamber and a lower chamber is disposed immediately below the molded body. manufacturing equipment. 2. The glass plate manufacturing apparatus according to claim 1, wherein the partition walls are arranged horizontally movably on both sides of the glass plate, and the tips of the partition walls facing each other are close to the glass plate. .