FI100180B - Method and apparatus for adjusting the bending of glass in a glass bending furnace - Google Patents

Description

100180 METHOD AND APPARATUS FOR ADJUSTING THE BENDING OF GLASS TO GLASS

bending furnace

The invention relates to a method and apparatus for controlling the gravity bending of glass in a bending furnace by limiting the temperature rise in a desired range in a glass sheet.

When using an edge mold for bending glass, the problem has been that the glass bends too much due to gravity, usually from the middle stages of the glass, before the edge areas of the glass have had time to bend even the desired amount. This is especially true when bending large windshields with an edge mold. Such glasses are typically bent in a single or multi-chamber furnace where heating is performed by radiating elements above the glass sheet. The problem has been reduced by connecting the radiating elements only to a stronger bend.

As additional devices for reducing the problem, e.g. various plates shielding the radiation of the heating elements above the glass where excessive bending would occur. Solid metal sheets placed under the glass have also been used locally to reduce the heating of the glass sheet.

• · · The disadvantage of these accessories is the slowed down heating rate, which has to be used due to the risk of glass breakage.

· Φ · · The solid plate and shading cause temperature differences to la-: * Γ and therefore the maximum heating speed cannot be used at temperatures between 20 * and 500 ° C. Only at temperatures above 500 * C can even large temperature differences be maintained and not the above.

• · · · then there is no problem with accessories. They extend the heating time and the solid plate also extends the cooling time. These «« · *. · * Factors also mean that due to the above-mentioned devices, the bending process consumes more energy.

, ··. The method and device according to the invention solve the problem that arises and the invention is characterized by what is stated in the claims.

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The object of the invention is to provide a low-mass cooling surface which, at least in the bending compartment, is in connection with a flexible glass sheet causing temperature differences in the glass. A casing-shaped flat surface made of, for example, two thin sheets by joining it, placed below the glass sheet, does not interfere with the heating of the glass. Advantageously, the surface can only be tuned to operation at a given moment by means of compressed air blowing. When the supplied compressed air is led into and out of the housing-shaped structure, no flow disturbances are caused in the furnace. The temperature or amount of compressed air can be used to control the surface temperature and thus the effect on the glass. Cooling in the housing is only used at the end of the heating phase, when harmful bending would begin, at temperatures above 550 ° C. The actual heating cycle can thus be performed quickly.

In the case of laminated-glass windscreens, the method makes it possible, in particular, to ensure that, in the joint bending of the two glasses, the lower glass does not bend too much in the middle due to gravity. This can easily take place if the aim is to limit bending in a known manner above the glass plate, e.g.

. by shading the resistance elements. In this case, the upper glass of the overlapping glasses may heat up less than the lower glass and remain straighter.

The most preferred embodiment is a housing under the glass, which provides a lot of surface area with as little grit as possible. Such a housing can be fixedly built into the edge mold, the edge mold transport base or the furnace bending compartment.

:. *. It can also be built into the bending section of a series furnace, where • · · ·. ··. ·. they, for example, the edge molds in turn move along the path and • · · created the mold and the glass plate can stop at it and pass • · · *. *: over.

• · · i: II ·

In the following, the invention will be explained in more detail with reference to the accompanying drawing, in which

Figure 1 shows the side of the glass resting on the edge mold.

Figure 2 shows an oblique view of the bent glass resting on the edge mold in the oven.

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Figure 1 shows a hinged edge mold on which a glass plate 1 is mounted. The supports 4 of the ends of the mold are hinged by means of joints 5 in a manner known per se. Thanks to the weights 6, the glass initially rests on several points until the bending of the glass and the correct dimensioning of the weights 6 finally pivots the brackets 4 up to their movement limiters, whereby the edges of the central part of the glass also sink on the mold brackets 8.

The housing according to the invention is placed in the mold so that it is under the glass plate approximately in the middle of the glass.

Figure 2 is an oblique view of the mold in a 1-chamber furnace, a typical bending furnace for large windshields. The glass 1 is bent according to the edge mold into its final shape. There is a small bending radius on each side of the glass, as a result of which the heat has had to be directed most to these edges of the glass in order for gravity to be able to perform the bending. However, the glass also heats up excessively from the middle part, which still lacks support. The cooled housing 3 according to the invention prevents excessive bending of the glass in its central part, keeping the temperature of the glass lower. In this case, the stiffness of the glass is maintained in the middle part and no excessive dependence has arisen.

Cooling compressed air is introduced into the housing 3 only when the temperature of the central part of the glass Γ ". # Has exceeded 550" c. To conduct the compressed air, there are • · · '1', 'connections in the housing 7. Compressed air is led out of the housing along a pipe • · · to the outside of the oven to prevent harmful flows into the oven. The housing has a cooling effect both as heat • ♦: transmitted from the glass to the housing and, to a lesser extent, as convection between them.

• · · • · · • · · ···. The distance of the housing 3 can be adjusted with respect to the glass, whereby "a power control is achieved. The amount of compressed air or the temperature can also be adjusted and different cooling effects on the glass can be achieved. If necessary, the shape and size of the housing provide different cooling effects. placed.

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Instead of a single-chamber furnace, the housing according to the invention can also be placed in a bending compartment fixedly in series furnaces, whereby the mold and glass come along it or movably into the bending compartment, whereby it is moved under glass by means of a mechanism when needed.

The housing according to the invention can also be fixedly located in the edge mold of the series furnace running along the track, and compressed air is connected to it in the bending compartment. It can also be located in the mold transport base and can be adjusted to different height positions there.

Instead of the housing, the plane may be a plate with a heat-conducting tubular coil on the lower surface through which compressed air passes.

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Claims (9)

100180 1. A first-instance contract for the manufacture of glass and glass products (1) for the manufacture of glass products (4,8) and for the manufacture of glass products, including glass products the temperature of the genome of the air in the envelope of the glass and the glass mass of the glass (3) is exposed to the glass or glass of the glass (1) via radiation av nämnda box. • · A method for controlling the deflection of glass in a glass bending furnace, in which the glass sheet (1) is supported e.g. by an edge mold (4.8) and deflection occurs mainly by gravity, characterized in that the temperature distribution of the glass (1) during deflection is influenced by blowing air in the glass deflection direction - or cooling in a substantially flat and low-mass housing (3) arranged below the furnace to provide an effect on the glass plate (1) through radiation and convection at least at said housing. 2. For the purposes of the patent law, the provisions of Article 1 • · · ·; . ·. av, att luft ledes i i boxen (3) at a temperature of 450 ° C. • · · • · · Method according to Claim 1, characterized in that air is introduced into the housing (3) when the temperature of the glass exceeds 450 ° C. 3. A patent according to claim 1 and 2 is provided, the box (3) being provided in the form of an outer glove. • · ·. ···. 4. Förfarande enligt nägot av föregäende patentkrav 1-3 kännetecknat av, att boxen (3) placeras i böj- • · · '·' · ningsugnen head glasskivans (1) motsatt sida i anseende account ** '* · glasets värme-elementen . 100180 Method according to Claims 1 and 2, characterized in that the size, shape or number of the housing (3) is selected according to the type of glass to be bent. Method according to one of the preceding claims 1 to 3, characterized in that the housing (3) is placed in the bending furnace on the opposite side of the glass plate (1) to the heating elements of the glass. «« 1 5. A preferred embodiment of a patent according to claims 1-4 is shown in the box, (3) mounted in a single frame and in a form according to the form, ex. with cantform (4.8). Method according to one of the preceding claims 1 to 4, characterized in that the housing (3) is mounted in a single chamber; in the oven in connection with a mold, e.g. an edge mold (4.8). • · · • · · • · · · 6. An embodiment according to the preceding claims 1-5 of the invention, the box (3) is mounted in a single chamber according to which a fast apparatus or a chamber or a chamber is used in the form of a chamber. Method according to one of the preceding claims 1 to 3, characterized in that the housing (3) is mounted in a multi-compartment series furnace in its bending compartment either in the bending compartment as a fixed device or along a path as an accompanying device. «· · • · 7. Apparatus for adjusting the deflection of glass in a glass bending furnace, in which the glass sheet (1) is supported, for example, by an edge mold (4.8) and deflection occurs mainly by gravity, characterized in that the apparatus comprises: one or more substantially flat, low-mass housings (3) to be placed above or below the glass • and a compressed air piping connected to the housing to conduct compressed air to and from the housing during bending of the glass. Apparatus according to claim 7, characterized in that the housing is flat in the direction of the glass (1) and is constructed and dimensioned to belong integrally to the mold (4,8). Apparatus according to claim 7, characterized in that the housing (3) is arranged in a glass bending furnace in a bending compartment and is located or movable along a path in connection with a mold entering said compartment. 7. Anordning för justering av glasets böjning i en glasböj-ningsugn, där glasskivan (1) bars till ex. with a uniform shape (4,8) and with a cross-section of the glass body, with a flat glass, in the case of a flat glass, in the case of a flat glass 3) the same as the box with the back of the box under the glazing under the glazing of the box to the side of the drift. 8. Anordningen enligt patentkrav 7 kännetecknad därav, att boxen är flat i glasets (1) riktning and har const-ruerats oc mätts att höra fast till molden (4,8) | i ' 9. A method according to claim 7 for the manufacture of a box, (3) a placebo and a glazing chamber and a bridging chamber and a placebo with or without a fly ash. band med en form, som kommer account nämda kammare längst en bana. 1 · · 4 · · • · · «• · · * · · · · * * · · · · ··· · · · · ·«