JP2022163758A - Apparatus and method for molding glass into curved surface shape - Google Patents

Abstract

To provide an apparatus and method for molding glass into a curved surface, capable of achieving the complicated curved surface of glass and achieving an optical mirror surface after the molding.SOLUTION: An apparatus for molding glass into a curved surface includes: a lower die 31 including one or more cavities and capable of placing a glass plate to suck the glass plate under vacuum; and a plurality of infrared heaters 11. The plurality of infrared heaters are arranged in parallel to the upper surface of the lower die 31 in the longitudinal direction, and the individual control of the plurality of infrared heaters 11 arranged in parallel hangs a desired position of the glass plate by self-weight to mold the glass plate into a predetermined curvature.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to an apparatus and method for shaping glass into a curved shape, and more particularly to an apparatus and method for shaping glass into a curved shape for realizing a complicated curved shape.

Due to the development of multimedia, various shapes and curvatures are required for glass used in display devices. In particular, automobiles are equipped with information display devices to satisfy HMI (Human Machine Interface). There is an in-vehicle display device that displays If such a vehicle-mounted display device or the like is to be realized with a thin plate glass, a more complicated curved surface is required. Moreover, along with the realization of complex curved glass, an optical mirror surface after molding is required.

In general, methods for molding glass for automobiles include methods such as self-weight bending and press bending, in which glass is heated to a softening point or higher and then bent by its own weight or by pressing. A press molding method is used to form particularly deeply curved glass or horseshoe-shaped glass. In the invention according to Patent Document 1, in a press bending method of press bending using a mold, the stress generated in the glass plate by press bending is calculated, and the stress obtained by the stress calculation is the in-plane compressive stress. proposed a method of press-bending a glass sheet under press-bending conditions in which the in-plane compressive stress is below the allowable value calculated by the buckling theory. Although such a molding method is excellent in production efficiency, it is particularly difficult to realize a complicated curved glass surface, and a technical problem remains when it comes to a highly accurate optical mirror surface. In addition, if the upper and lower dies are strongly pressed, it may be possible to create a complex curved surface of the glass, but the glass after molding becomes white and opaque, and wrinkles often appear around the glass surface. There is a problem that a high-precision optical mirror surface cannot be achieved unless polishing takes longer than after normal pressing. Furthermore, it costs a lot to create a mold for molding glass for an in-vehicle display device called CID (Center Information Display) or Cluster, and it is difficult to make the glass curved.

Another known method is bending with a roller assembly. The invention according to Patent Document 2 proposes a method of bending and forming a glass sheet by conveying the glass sheet heated to near the softening point in a heating furnace with a roller conveyor comprising a plurality of curved rollers. According to this method, the softened glass sheet hangs down due to its own weight, so that the glass sheet is bent so as to follow the curvature of the roller. In this case, the glass sheet is bent in a direction orthogonal to the conveying direction. The invention according to Patent Document 3 proposes, in the roller assembly according to Patent Document 2, to bend the glass plate by pressing the conveying roller against the glass plate while moving it up and down as the glass is conveyed.
However, in the method of Patent Document 1, it is necessary to replace the roller with a roller having a curvature corresponding to the model for each model. Further, there is a problem that streak-like roller strain is formed in the vertical direction in the assembled state due to the contact of the roller with the glass plate, and the streak-like strain due to the roller tends to be conspicuous. In addition, in the method of Patent Documents 2 and 3, it is necessary to vertically move a large number of conveying rollers in the case of molding a large glass, which complicates control and may cause damage to the glass plate. There is a problem. Furthermore, it is difficult for the methods of Patent Documents 1 to 3 to deal with the complicated curved surface of slightly large-sized glass used in vehicle-mounted display devices.

JP 2005-154164 A U.S. Pat. No. 4,123,246 JP-A-2000-72460 JP 2019-189512 A

In view of the above problems, the applicant of the present application has proposed, in Patent Document 4, a glass curved surface forming apparatus and method for realizing a complicated curved glass surface and an optical mirror surface after forming. That is, a glass curved surface comprising a lower mold having a plurality of cavities for placing a glass plate having a desired curved surface and vacuuming, and one or more pressure rollers for pressing the glass in a desired bending direction. A forming apparatus, in which a glass sheet heated to a bending temperature is placed on a lower mold, and one or more pressure rollers apply pressure while rolling along a desired curved surface of the lower mold. At the same time, the cavity immediately after one or more pressure rollers roll in the lower mold is evacuated to form the glass sheet with a predetermined curvature.
However, when a cold roller is pressed against the heated glass, the glass breaks due to thermal shock. I had a problem with it getting worse. There is also a problem that the softened glass is scratched by pressing a metal roller against it. Furthermore, even if the glass plate is heated by an infrared heater, there is a problem that a desired curvature cannot be obtained unless only the portion of the glass plate to be bent is selectively heated more finely.
In order to solve these problems, the present invention is a glass curved surface molding apparatus that realizes a complicated curved glass surface and an optical mirror surface after molding by devising the roller structure and the arrangement of infrared heaters. The subject is to propose the method.

In order to solve the above problems, the apparatus for forming a curved glass surface according to the present invention includes a lower mold having one or more cavities on which a glass sheet is placed and capable of evacuating the glass sheet, and a plurality of infrared heaters. In the curved surface forming apparatus, a plurality of infrared heaters are arranged in parallel in the longitudinal direction on the upper surface of the lower mold, and the plurality of infrared heaters arranged in parallel are individually controlled to adjust the glass sheet to a desired position under its own weight. It is characterized by forming a glass plate with a predetermined curvature.

Equipped with a lower mold having one or more cavities in which a glass plate is placed and which can be evacuated, one or more pressure rollers for applying pressure to the glass plate in a desired bending direction, and a plurality of infrared heaters. A glass curved surface molding apparatus, wherein the pressure roller has a roller outer peripheral surface covered with a heat-resistant cloth, and the plurality of infrared heaters are arranged in parallel in the longitudinal direction with respect to the upper surface of the lower mold, and the plurality of infrared heaters arranged in parallel. The glass sheet is formed to have a predetermined curvature by selectively heating an arbitrary infrared heater capable of heating a desired portion of the glass sheet placed on the lower mold.
The heat-resistant cloth is preferably a woven cloth made of fiber selected from glass fiber, silica fiber, alumina fiber, and ceramic fiber. Considering heat resistance, workability, texture, etc., silica fiber cloth or aramid fiber is most suitable. Flame resistant fibers may also be selected. Applying these heat-resistant cloths to the outer peripheral surface of the roller prevents thermal shock and prevents damage to the glass. Furthermore, the material of the roller is preferably metal or ceramics.

In the curved glass surface forming apparatus according to the present invention, one or more pressure rollers roll along the desired curved surface of the lower die while the infrared heater heats the desired portion of the glass sheet to the bending temperature. It is preferable that the pressure is applied while Further, the glass sheet may be molded to have a predetermined curvature by evacuating the cavity immediately after the one or more pressure rollers roll in the lower mold.

A method for forming a curved glass surface according to the present invention includes a glass curved surface forming apparatus comprising a lower mold having one or a plurality of cavities in which a glass plate is placed and capable of being evacuated from the glass plate, and a plurality of infrared heaters. The heaters are arranged in parallel on the upper surface of the lower mold in the longitudinal direction, and by individually controlling the plurality of infrared heaters arranged in parallel, the desired position of the heated glass plate is moved to the curved surface of the lower mold by its own weight. It is characterized by forming the glass plate into a predetermined curvature by hanging down along the length of the glass plate.

Further, the method for forming a curved glass surface according to the present invention includes a lower mold having one or more cavities in which a glass plate is placed and vacuumed, and a glass plate provided above the lower mold to press the glass plate in a desired bending direction. In a glass curved surface forming apparatus comprising one or more pressure rollers and a plurality of infrared heaters, a step of placing a glass sheet on a lower mold, and softening in which a desired portion of the glass sheet is bent by its own weight with an arbitrary infrared heater. a pressure roller intervening between the infrared heater and the glass plate as the infrared heater moves upward; and a step of applying pressure toward a desired portion of the roller while rolling the roller.

Further, the method for forming a curved glass surface according to the present invention includes, following the above steps, a forming step of forming a predetermined curvature by evacuating the cavity immediately after the one or more pressing rollers roll in the lower mold. You may make it consist from.

According to the method and apparatus for forming a curved surface of glass according to the present invention, by individually controlling the infrared heaters, which are heating elements arranged in a plurality, the desired bending position of the glass sheet can hang down on the curved surface of the lower die by its own weight. It becomes possible. When a roller is used, applying a heat-resistant cloth to the outer peripheral surface of the roller prevents thermal shock and prevents damage to the glass. In addition, it becomes possible to realize a slightly complicated curved surface of the glass and to realize an optical mirror surface after molding. In addition, since the thickness of the glass sheet and the bent shape of the glass sheet vary widely, the bending using the pressure roller is flexible and more cost-effective than the press forming using the upper and lower dies.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram showing a glass curved surface forming apparatus 100 according to Example 1 of the present invention; It is a figure showing a part of roller device 20 concerning Example 1 of the present invention. 4 is a flow chart showing steps in the method for forming a curved surface of glass according to Example 1 of the present invention when the pressure roller 21 is not used. FIG. 4 is a diagram showing how curved glass is formed without using a pressure roller 21 in the method for forming a curved glass surface according to the first embodiment of the present invention. 5 is a flow chart showing the process of forming a curved glass surface by rolling and pressing a pressing roller 21 in the method for forming a curved glass surface according to Example 1 of the present invention. FIG. 2 is a diagram simply showing rolling and pressing of a pressing roller 21 in forming a curved glass surface according to Example 1 of the present invention. FIG. 7 is a diagram simply showing the rolling and pressing of the pressing roller 21 subsequent to FIG. 6 in the glass curved surface forming according to Example 1 of the present invention.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. In each figure, the same parts are denoted by the same numbers, and overlapping descriptions are omitted. Also, it should be noted that the drawings may be exaggerated for better understanding of the present invention and are not necessarily drawn to scale. In addition, the present invention is not limited to the examples shown below.

Embodiment 1 will be described in detail with reference to the drawings.

Embodiment 1 FIG. 1 is a schematic configuration diagram showing a glass curved surface forming apparatus 100 according to Embodiment 1 of the present invention. A detailed description will be given with reference to FIG. A glass curved surface forming apparatus 100 generally has a structure in which a heating section 1 and a forming section 2 are connected to each other, and a lower mold 31 is placed on a mold table 30 .

As shown in FIG. 1, the heating section 1 is composed of an infrared heater 11 and a heater support member 12 . The heater 11 is preferably supported by a heater support member 12 and driven vertically by servo control. Similarly, the forming unit 2 is preferably configured such that the roller device 20 is installed on the track body 23 and is driven by servo control.
The plurality of infrared heaters 11 are arranged in parallel in the longitudinal direction with respect to the upper surface of the lower mold 31, and among the plurality of infrared heaters 11 arranged in parallel, a desired portion of the glass plate placed on the lower mold 31 is heated. By selectively heating the infrared heater 11 that can be used, the glass plate can be formed to have a predetermined curvature.

FIG. 2 is a diagram showing part of the roller device 20 according to the first embodiment of the invention. The roller device 20 will now be described in detail with reference to FIGS. 1 and 2(a). The roller device 20 generally consists of a pressure roller 21 and a roller shaft 22 . The pressure roller 21 is rotatably supported by a roller shaft 22 , is attached to a track 23 , and moves along the track of the track 23 with a sliding cylinder. Servomotors are used to control pressure, speed and alignment, which are important molding conditions. The pressing roller 21 presses a glass plate G placed on a lower mold 31 to be described later while rolling.
The material of the pressing roller 21 is preferably heat-resistant metal or ceramics. Further, in the first embodiment, the pressing roller 21 employs a cylindrical body, but may employ a spherical body or a conical body.

Please refer to FIG. The pressure roller 21 has a roller outer peripheral surface 210 covered with a heat-resistant cloth 211 . The heat-resistant cloth 211 is preferably made of a woven fabric selected from glass fiber, silica fiber, alumina fiber, and ceramic fiber. Considering heat resistance, workability, texture, etc., silica fiber or aramid fiber cloth is most suitable. Flame resistant fibers may also be selected. Applying these heat-resistant cloths 211 to the outer peripheral surface 210 of the roller prevents the occurrence of thermal shock and also leads to the prevention of scratches on the glass.

The lower mold 31 has a plurality of cavities in which the glass sheets can be placed and the glass sheets can be evacuated. The material of the lower mold 31 is preferably metal or ceramics. In the case of ceramics, it should be fire-resistant, have excellent specularity after processing, and have good releasability from the glass even at high temperatures. preferable.

Please refer to FIGS. FIG. 3 is a flow chart showing steps in the method for forming a curved surface of glass according to the first embodiment of the present invention when the pressure roller 21 is not used. 4A and 4B are diagrams showing how glass is formed into a curved surface when the pressure roller 21 is not used in the method for forming a curved glass surface according to the first embodiment of the present invention.

In forming the desired curved surface of the glass plate, when the curvature is shallow, a lower die 31 as shown in FIG. 4 is used. In this case, molding is possible by selectively heating the glass sheet by the arbitrary infrared heater 11 so that the glass sheet follows the curved surface of the lower die 31 by its own weight. In the first embodiment, as shown in FIG. 4, the infrared heaters 11 consist of 12 infrared heaters (a, b, c, d, e, f, g, c, l, n, l, w) which are connected to the lower die. 31 or arranged in parallel above the glass plate G placed thereon. The number of infrared heaters is not particularly limited, and can be appropriately determined according to the dimensions of the glass plate to be molded and the design conditions of curved surface molding.

The process of FIG. 3 will be described with reference to FIG. First, as shown in FIG. 4A, a glass plate is placed on the upper surface of the lower mold 31, and the entire glass plate G is heated by a plurality of infrared heaters 11 (S01). Next, as shown in FIG. 4B, the heating output of the infrared heater 11 is increased to further heat the region A of the glass plate G to near the softening point, and the glass plate G is made to follow the curved surface of the lower die 31 by its own weight (S02). . Then, as shown in FIG. 4(c), the heating output of E of the infrared heater 11 is increased to further heat the region B of the glass plate G to the vicinity of the softening point. By increasing the heating output of the infrared heater 11 in areas B, C, and D, the area C of the glass sheet G is further heated to near the softening point, and is made to follow the curved surface of the lower die 31 by its own weight (S03, S04). If necessary, the cavity of the lower mold 31 may be evacuated (S05). It should be noted that the lower die 31 is preferably designed to have one or a plurality of cavities.

See FIGS. 5, 6 and 7. FIG. FIG. 5 is a flow chart showing steps in the case of using the pressing roller 21 in the method for forming a curved glass surface according to the first embodiment of the present invention. FIGS. 6 and 7 are diagrams showing simply how the glass sheet G is heated and the pressing roller 21 rolls and presses in curved glass forming according to Example 1 of the present invention. ) are shown in chronological order, and FIG. 7(a) should be understood as a diagram showing the state after FIG. 6(c).

The process of FIG. 5 will be described with reference to FIGS. First, as shown in FIG. 6A, the glass plate G is placed on the upper surface of the lower mold 32, and the entire glass plate G is heated by the plurality of infrared heaters 11 (S11). Next, as shown in FIG. 6(b), the heating output of the infrared heater 11 is increased to further heat the A region of the glass plate G to near the softening point, and the glass plate G is made to follow the curved surface of the lower mold 32 by its own weight (S12). . Then, as shown in FIG. 6(c), the heating output of the infrared heater 11 is increased to further heat the region B of the glass plate G to near the softening point (S13).
After selectively heating the A and B regions of the glass plate G and making it follow the lower die 32 by its own weight, the infrared heater 11 is moved upward as shown in FIG. 7(a) (S14). When the infrared heater 11 moves upward, the pressing roller 21 enters between the infrared heater 11 and the glass G and stands by at a predetermined position on the upper surface of the glass plate G, as shown in FIG. 7(b) (S15). Then, as shown in FIG. 7(c), the pressing roller 21 presses the glass plate G while rotating along the undulations of the lower die 32 (S16). If necessary, the cavity of the lower mold 32 may be evacuated (S17). It should be noted that the lower die 32 is preferably designed to have one or a plurality of cavities.

Although the preferred embodiments of the glass curved surface forming apparatus and method according to the present invention have been illustrated and described above, it is understood that various modifications can be made without departing from the technical scope of the present invention. Will.

In the method and apparatus for forming a curved surface of glass according to the present invention, a plurality of infrared heaters, which are heating elements, are individually controlled so that the desired bending position of the glass sheet can hang down on the curved surface of the lower die by its own weight. Become. When a roller is used, applying a heat-resistant cloth to the outer peripheral surface of the roller prevents thermal shock and prevents damage to the glass. As a result, a curved surface and an optical mirror surface with high-quality surface properties can be realized on the glass plate, so that the molded glass can be widely used for in-vehicle display devices and the like.

100 Glass Curved Surface Forming Apparatus 1 Heating Part 11 Heater 12 Heater Support Arm 2 Forming Part 20 Roller Device 21 Pressing Roller 210 Roller Peripheral Surface 211 Heat Resistant Cloth 22 Roller Shaft 23 Race Body 31 32 Lower Mold G Glass Plate

Claims (8)

A glass curved surface forming apparatus comprising a lower mold having one or more cavities in which a glass plate is placed and capable of being evacuated from the glass plate, and a plurality of infrared heaters,
The plurality of infrared heaters are arranged in parallel in the longitudinal direction with respect to the upper surface of the lower mold, and by individually controlling the plurality of infrared heaters arranged in parallel, a desired position of the glass plate hangs down due to its own weight, A curved glass forming apparatus for forming the glass plate to have a predetermined curvature. Equipped with a lower mold having one or more cavities in which a glass plate is placed and which can be evacuated, one or more pressure rollers for applying pressure to the glass plate in a desired bending direction, and a plurality of infrared heaters. A glass curved surface forming apparatus,
The pressure roller has a roller outer peripheral surface covered with a heat-resistant cloth,
The plurality of infrared heaters are arranged in parallel in the longitudinal direction with respect to the upper surface of the lower mold. An apparatus for forming a curved glass surface, wherein the glass sheet is formed to have a predetermined curvature by selectively heating an arbitrary infrared heater capable of heating. 3. The apparatus for forming curved glass surfaces according to claim 2, wherein the heat-resistant cloth is a woven fabric of fibers selected from glass fibers, silica fibers, alumina fibers, ceramic fibers, and aramid fibers. In a state in which the infrared heater heats a desired portion of the glass sheet to a bending temperature, the one or more pressure rollers apply pressure while rolling along the desired curved surface of the lower die. 4. The apparatus for forming a curved glass surface according to claim 2 or 3, wherein 5. The glass curved surface forming apparatus according to claim 4, wherein the glass plate is formed to have a predetermined curvature by evacuating the cavity immediately after the one or more pressure rollers roll in the lower mold. . A glass curved surface forming apparatus comprising a lower mold having one or more cavities in which a glass plate can be placed and which can be evacuated, and a plurality of infrared heaters,
The plurality of infrared heaters are arranged in parallel in the longitudinal direction with respect to the upper surface of the lower mold, and by individually controlling the plurality of infrared heaters arranged in parallel, desired positions of the heated glass sheet are controlled. A method for forming a curved glass surface, wherein the glass plate is formed to have a predetermined curvature by hanging down along the curved surface of the lower mold due to its own weight. A lower mold having one or more cavities in which a glass plate is placed and vacuumed, one or more pressure rollers provided above the lower mold for applying pressure to the glass plate in a desired bending direction, and a plurality of infrared rays. A glass curved surface forming apparatus comprising a heater,
placing the glass plate on the lower mold;
a step of selectively heating a desired portion of the glass plate with the arbitrary infrared heater to a softening point at which the glass plate bends under its own weight;
when the infrared heater moves upward, the pressure roller intervenes between the infrared heater and the glass plate;
a step in which the one or more pressing rollers roll along the curved surface of the lower mold on a desired portion of the glass sheet while applying pressure toward the desired portion;
A glass curved surface molding method comprising: A lower mold having one or more cavities in which a glass plate is placed and vacuumed, one or more pressure rollers provided above the lower mold for applying pressure to the glass plate in a desired bending direction, and a plurality of infrared rays. A glass curved surface forming apparatus comprising a heater,
placing the glass plate on the lower mold;
a step of selectively heating a desired portion of the glass plate with the arbitrary infrared heater to a softening point at which the glass plate bends under its own weight;
when the infrared heater moves upward, the pressure roller intervenes between the infrared heater and the glass plate;
a step in which the one or more pressing rollers roll along the curved surface of the lower mold on a desired portion of the glass sheet while applying pressure toward the desired portion;
Furthermore, a molding step of molding the cavity to a predetermined curvature by vacuuming the cavity immediately after the one or more pressing rollers roll in the lower mold;
A glass curved surface molding method characterized by comprising:

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