JPH02172833A - Bent glass sheet - Google Patents

Abstract

PURPOSE:To prevent the distortion of a reflected image by specifying the degree of fine concave or convex deformation within a specified range of a bent glass sheet from each edge. CONSTITUTION:A bent glass sheet having <=2,000mmR curvature is formed so as to regulate the degree of concave or convex deformation, especially reversely warped concave deformation from the designed bent surface to <=0.05mm within 150mm range of the sheet from each edge. Asymmetric distortion is prevented in the range and matchability is improved when the sheet is fixed in a window frame. Grating is prevented at the time of ascent and descent and fine appearance is obtd.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a single-pane, double-layer, or laminated glass, either raw or tempered, for use in vehicle window glasses such as automobiles, architectural window glasses, etc. This invention relates to a bent glass that eliminates the phenomenon in which a reflected image appears distorted near the edge of the glass.

[Prior Art] Conventionally, in various types of bent glass, especially tempered glass, the smaller the curvature of the bend, the more distorted the reflected image near the edge of the glass plate. Due to the increasing demand for bent glass, there is a demand for good-looking automobile window glass in particular.

Therefore, various bending forming methods have been proposed in an attempt to solve optical distortions such as overlapping. That is, JP-A-61-183138 describes a press bending apparatus for sheet glass, and in the case of automobile window glasses, etc., the curvature seems to be large at the periphery and small at the center. However, each part has a different curvature, and optical distortion is likely to occur in parts with large curvatures, that is, rounded parts. An auxiliary press is placed between the mold and the mold so that it can move up and down, and before forming the glass plate between the upper and lower molds,
By pre-forming the portion that will become the small radius portion in advance, the plate glass and the molding surface of each mold do not come into uneven contact, and
A means for suppressing the contact pressure by preventing it from becoming large in some parts is described, and Japanese Patent Application Laid-Open No. 61-91
Publication No. 025 describes a press molding apparatus for sheet glass, which produces a drooping part in the peripheral part of the temporary glass where the ring mold did not touch, and a reflection distortion called a highlight occurs in this part, etc. In both cases, a concave portion is formed in the member corresponding to the ring mold to prevent it from interfering with the conveyance roller, which causes optical distortion.A ring mold consisting of a plurality of divided bodies is placed above the conveyance roller! Then, the plate glass taken up from the conveyance roller is taken up by a ring mold in which each divided body is combined, and press-formed between it and the upper mold in this state, eliminating the need to form a concave part and improving the shape of the plate glass. JP-A-61-270228 discloses a method in which the entire circumference is molded using a ring mold, and regarding self-weight bending, Japanese Patent Application Laid-Open No. 61-270228 describes a method in which the upper surface of the mold is discontinuous at the position of the opening of the groove. This discontinuous part does not come into contact with the plate glass, and optical distortion due to reflected light occurs at the periphery of the plate glass. The transport rollers placed above the mold are able to move up and down, and are sized to fit within the recess or space of the mold when lowered, so that the contact between the transport rollers and the sheet glass is improved. It is stated that since the contact pressure can be reduced and the contact time is shortened, the part that contacts the conveyance roller can be cooled and suppressed compared to the surrounding area. A forming method is described in which a removable heat ray reflective coating is formed in advance on the longitudinal side edges of the glass plate before heating to lower the temperature of this area and reduce sag. In addition, special public service 1984-4
Japanese Patent Laid-Open No. 2939 describes a method of bending a glass sheet by bending under its own weight, in particular to suppress sagging and doubling in the central part, and JP-A No. 56-22643 describes a method for bending a glass plate by bending under its own weight to suppress sagging and doubling. By providing a conductive path on the surface of the temporary glass, each of the adjacent glass sheet parts of the bent sheet glass has a curved surface shape, so that the glass sheet is curved in the opposite direction to the other curved surface portions. It is known that things are described.

[Problems to be Solved by the Invention] As mentioned above, in the conventional bend forming method, 2. Especially in the bend forming method where the curvature is 20005 mR or less,
It was not always possible to obtain a bent glass without distortion of the reflected image near the edge of the glass plate, and it was not always satisfactory. Distortion of the reflected image is particularly likely to occur on both the left and right sides, that is, near the edges of the short sides, and from the aesthetic point of view, a bent glass without distortion of the reflected image has been desired for automobile window glass.

Means for Solving Problem E] The present invention has been made in view of the conventional problems, and includes:
The present invention was achieved by discovering that when a glass plate is bent and formed, the amount of minute deformation that occurs within a specific range from the edge of the plate affects the distortion of the reflected image, and that the distortion can be resolved by specifying the amount of coughing. .

That is, the present invention provides a bent glass plate having a curvature of 2000 m or less, characterized in that the amount of minute unevenness deformation is 0.05++++a or less within 150 mm from the edge of the glass plate. It provides:

Here, the reason for using a bent glass plate with a curvature of 2000 sim R or less is that, for example, a flat tempered glass plate with a curvature of about 2500 mm R is contrary to the unevenness of a normally used automobile window glass. This is because the concave shape is small and distortion of the reflected image hardly becomes a problem.

In addition, the distance within 150 mm from the edge of the plate is approximately 150 mm from the edge of the plate if the unevenness, especially the concave phenomenon of reverse warpage, is the size that is normally used, for example, an automobile window glass.
This is because the concave phenomenon tends to occur within mm, and this concave phenomenon, for example, causes distortion of the reflected image. In particular, unevenness tends to occur in the area around 20 to 100 ra from the edge of the board.

Furthermore, the reason why the amount of micro-asperity deformation is set to 0.05+mm or less is because if it exceeds 0.05+m near the edge of the glass plate, the distortion of the reflected image will deteriorate, which may impair the aesthetic appearance of window glass for automobiles, for example. Naturally, this is because more accurate construction is not possible and the integrity of the installation will be subtly affected. In particular, when the object is bent with a certain curvature and is curved in the opposite direction, the distortion of the reflected image becomes significant. A preferable amount of the deformation is 0.03 cm or less.

Furthermore, the glass plate may be either inorganic or organic, and it goes without saying that it can be colorless or colored, and includes green or reinforced single glass, multilayer glass, and laminated glass.

Note that the present invention is particularly useful for those having a plate thickness of 5 mm or less.

[Function] As mentioned above, the bent glass plate of the present invention, especially when the curvature is 2
000mmR or less of bent glass, in the part within 1501 mm from the edge of the plate, the appearance of irregularities, especially reverse warped concave parts, from the designed bending surface, the amount of deformation is 0
．． By making the bent glass plate within 0.5mm,
In particular, in automobile window glass, such as door window glass, the concave portion whose curvature changes discontinuously becomes like a concave mirror, causing reflected image distortion, especially at the edges in the left and right width direction. By eliminating the phenomenon of unbalanced distortion near the edges, the installation of the glass plate to the window frame improves consistency over time, and improves aesthetics without causing creaks when going up and down. This ultimately leads to increased driving safety.

[Examples] Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples.

After heating a glass plate with a length of 9201L, a width of 560mm, and a plate thickness of 5mm to approximately 660°C, the press surface is continuously deformed into a convex shape by approximately 51 degrees near the end of the press surface compared to the conventional press surface. Then, molding was performed using a pair of concave and convex press surfaces improved as a composite design curved surface. Thereafter, air was blown to rapidly cool the glass plate to obtain a bent tempered glass plate with a curvature of about 1600 s+sR.

The span of the obtained bent tempered glass plate is approximately 70＠
The amount of deformation is measured using Otori's stylus-type dial gauge, and, for example, a reverse warped rotation is expressed as a positive value, and the distortion of the reflected image is determined by bending a panel with lines drawn on a grid with a length of 3 cm. Project it onto the tempered glass surface and take a photo of the reflected image. If the line per unit length of the panel on the resulting photo is approximately 1.6 times or more, it will be marked with an X and rejected. Those with a hit line of about 1.3 times or less were marked with an O mark and were marked as acceptable.

As shown in Table 1, the results were very good, with the amount of deformation being 0.03 mm or less in all parts, and no distortion of the reflected image.

119 In the process of heating a glass plate of the same size as in Example 1 to about 670°C, the curvature was reduced to about 14
A bent tempered glass plate of 00 mmH was obtained.

As a result of investigation using the same investigation method as in Example 1, as shown in Table 1, the amount of deformation in the vicinity of the edge of the obtained bent tempered glass plate was all 0.03 a + m or less, and distortion of the reflected image was also observed. The result was very good and similar to Example 1.

Actual ffi The results were carried out in the same manner as in Example 1 and Example 2, and as shown in Table 1, the results were similarly very good.

The same glass plate as in the Example was used, and the same glass plate was bent and formed using a normal pressing surface, and evaluated using the same investigation method as in the previous example. The results are shown in Table 1 as a comparative example.

In each of the obtained bent tempered glass plates, the amount of deformation of the reversely warped concave portion near the edge of the plate was about 0.15 to 0.3 mm, which was about 10 mm.
If the size is twice as large, the reflected image will be distorted, and improvements are desired.

Note that the same results as described above were obtained for raw boards.

[Effect of the invention] As described above, according to the present invention, the curvature is 2000+amR
In the following bent glass plate, the distortion of the reflected image is reduced by using a bent glass plate in which the amount of deformation of the unevenness near the edge of the plate, especially the reversely warped concave portion, is 0.05 mm or less, preferably 0.03 mm or less. Therefore, it is possible to provide a bent glass plate which is highly safe as an automobile window glass and has an aesthetic appearance.

Claims (1)

[Claims] 1. A bent glass plate having a curvature of 2000 mmR or less, wherein the amount of minute unevenness deformation is 0.05 mm or less within 150 mm from the edge of the glass plate.