MXPA97008355A - Procedure and device for abombing encristalados progresivame - Google Patents

Abstract

The present invention relates to a method for dipping glazing, the glazing of bulging in horizontal position in two successive bulging stations progressively in the final form. The encristalados (1) heated to the temperature of bulge, are placed on a support fabric (31) mounted flexible on a frame rigid carrier (30). The encristalados are transported stage by stage, with the support fabric (31) and the support frame, through the installation of bulge, and are bulged together with the support fabric (31) that adapts to the shape of the glazed

Description

A PROCEDURE AND DEVICE FOR ABOMBING PROGRESSIBLE ENCRYTICATED DESCRIPTION The present invention relates to a procedure The process for dipping gradually encristalados, in which the encristalados that are heated to the temperature of bulge, bulge in horizontal position in when 5 minus two stations of bulging successive gradually in the final form, are lifted by aspiration in the The last convex station with a convex top convex shape provided with suction holes and * are deposited on a movable carrier frame. The The invention also relates to devices for executing that method. The processes of bulging in several stages by progressive compression, are advantageous for various reasons. Above all, this type of multi-stage bending procedures allows the fabrication of complicated glazing shapes, for example spherical bulges, which in a process of bulging in a stage causes difficulties.

A two-stage bending process and a device suitable for carrying out the method are known, for example, from DE 4203751 C2. In the case of this known bulging process, the lower bending form and the upper bending form are conceived as rigid pressing tools in the two bending stations; the upper bending shapes are increasingly convex shapes of convex suction that cover all the surface. The pre-domed glazing is transferred with the aid of the first form of domed suction, in the next bulging compression station, while simultaneously, the domed glazing is conveyed by means of the domed form of aspiration of the second bulge station by compression, in a transfer station, in which the glazing is disposed on the carrier frame. The repeated pressing of the glazing at the moment of the bending process by means of the devices of , which causes the risk of the surface of the glass being altered by relative displacements between the glazing and the suction cupping devices. The object of the invention is to develop a progressive bending process comprising two or more than two bending stations in such a way that the relative displacements between the bearer devices that convey the encristalados through the domed installation, step by step , be small. In addition, the method should be suitable in particular for the bending of thin encristalados and also allow the realization of spherical bulges. This objective is achieved in accordance with the '> invention, due to the fact that the encristalados are transported by being placed on a flexible mounted support fabric on a rigid carrier frame, with the supporting fabric and the supporting frame, step by step, through the bending installation, and bulging together with the supporting fabric which is adapts to the form of the encristalados. Thanks to the method according to the invention, a series of essential advantages are acquired. On the other hand, the encristalado that presents the temperature of doming remains sustained throughout the curving operation, over its entire surface, which minimizes the risk of unwanted deformations of the glazing, for example under the effect of gravity. On the other hand, the relative displacements between the encristalado and the supports that convey the glazing through the installation, and therefore the risks of alterations of the surface of the glass, are completely avoided. In addition, the precision of the glazing placement in the different stations of the domed installation is increased, which improves the maintenance of the finished glazing form. Finally, the method according to the invention is advantageous due to the advantages mentioned, particularly for the spherical bulging of V- the very thin encristalados, for example encristalados less than 3 mm thick. According to the invention, the manufacture of glazed spherical glazing of low thickness is, in fact, a particularly critical operation, because very thin glazing have a particularly tendency to undulate slightly at the edge level at the time of the bending operation. -A In the advantageous development of the invention, the glazing is lowered during the course of a first bending stage by means of a molding tool The lower concave, whose outer surface, which holds the edge of the glazing, is essentially in a plane. At the time of pre-abortion, the glazing is pre-annealed first in this manner and stretched in its central part, while the edge of the glazing remains 5 in the initial plane. If the final bending occurs later in the course of a second bending stage, the risk of ripples at the edge level is considerably reduced. Another development of this procedure, consists of; that, in the course of the first bending stage, on the edge of the glazing, a tool is used that acts on its top part on that edge and compresses the immediate marginal zone against the flat marginal zone of the lower concave shape. Suitably, the conditions are selected in this case, such that only the extreme outer marginal region of the glazing is tightened or maintained. The method according to the invention can, for example, be conducted in such a way that the bending operation is carried out in two stages; the glazing can also be pre-inflated during the first bending stage by means of a convex convex shape that covers the entire surface that can be lowered onto the glazing. Suitably, the upper convex convex shape cooperates in this case with a lower concave bending shape, which is mounted so that it can be raised and lowered below the transport plane of the support fabric. rf- In a particularly advantageous manner. the bending operation, however, is carried out in the first bending station under the effect of a pneumatic pressure difference, and this, with the help of a concave bending shape that covers the entire surface and in which a depression can act by means of the holes made in the molding surface. The suction cup shape is also mounted so that it can be raised and lowered below the transport plane of the support fabric. After the suction-dome operation, under the effect of a brief air-release, the support fabric with the pre-embossed glazing is released from the molding surface, the suction-shaped dome shape is lowered and the carrier frame is transported with the pre-domed glazing, in the final bending station. Other features and advantages of the invention will be apparent from the dependent claims and from the following description of preferred examples of embodiments with the help of the drawings. In the drawings: Figure 1 is a schematic perspective view of a first embodiment of a bulging installation in accordance with the invention; Figure 2 is a schematic perspective view also of a second embodiment of a bulging installation according to the invention; Figure 3 is a sectional view of a suction bulging device according to the invention; Figure 4 is a view also in section, of a suction cupping device with a plate T supplementary retention for the edge of the glazing; Y Figure 5 is a view also in section of a suction cupping device with a supplementary pressure supply. Before glazing 1 is bulged in a bulging facility in accordance with the invention, are heated in an appropriate oven, at the convex temperature. In the case of the oven, which is not represented as -K such in the figures, can be, for example, a continuous roller furnace through which the encristalados are transported on transport trees driven 3. At the exit from the continuous furnace, they are lifted from the transport rollers with a flat-suction plate 3 on their lower face. The plate-sucker 3 can be moved linearly in an appropriate manner and the glazing 1 comes out of the oven to be brought into the bending installation 5.

The bending installation comprises a pre-bending station 10 and a final bending station 20. In addition, the bending installation in figure 1 comprises a system for conveying the glazing, comprising several carrying frames 30 movable in the direction of the arrow F, on which each time a section of flexible mounted fabric 31 is laid. This section of fabric 31 serves as support for the hot glazing. Suitable materials for this fabric are composed in particular of refractory metal fibers and are known as such and available on the market. According to the desired elasticity and flexibility that this support material must have, fabrics of appropriate meshes made of refractory metal fibers can be used instead of fabrics. The fabric sections 31 rest on two opposite rods 33 of the frame 30 and pass freely above the rods 32. At their ends, the metal rods 33 are fixed which are provided with weight materials such that, on the one hand, they secure the necessary tension of the support fabric and, on the other hand, nevertheless limit the tension of the support fabric to a value such that this fabric retains, after the pre-bulging operation, the shape predefined by the glazing under the effect of the weight of that glazing. The carrier frames 30 provided with carrier fabrics 31 are routed, step by step, cyclically through the bending installation. The transport system as such is not represented in order to obtain a better overall view. The first bending station, which is described as a pre-domed station 10 of the bending installation, comprises a form of suction bending ^ bottom 12, which is mounted so as to be able to rise and lowered, for example with the help of a hydraulic jack 13. The shape of suction cup 12 has a concave molding surface 14, in which many openings 15 can be opened, which can be fed with a depression. The dome size of the surface of concave molding 14, corresponds almost to half . i of the curvature of the definitive form of glazing.

The surface 16 of the suction cup shape contiguous with the concave molding surface 14 is in a plane, such that the edge of glazing, after this pre-bulging stage, is also in a plane, independently of the shape that the glazing presents and its outline, after the last bulging stage. Also in the final bulging station 20, the The shape of the domed interior 22 is mounted in such a way that it can be raised and lowered with the aid of a hydraulic jack 23. In the case of this form of lower curvature 22, it can be a domed form covering the entire surface or a domed form of the frame type. This lower bulging shape 22 cooperates with the upper bulging shape 24 covering the entire surface, which is also mounted so that it can be lifted and lowered by means of an appropriate driving device, - r for example, a hydraulic jack. The shape of domed The convex 24 covering the entire surface is customarily provided, in a known manner, with holes that can be fed, on the one hand, with a depression and, on the other hand, with an overpressure, and is covered, on the molding surface, with a fiber cloth refractory The final bulging station 20 is followed by ^ a cooling station, in this case, a usual device that is not shown here. With the help of a movable carrier frame 26 corresponding to the shape of the edge of the domed glazing, the domed glazing rises from the upper domed form 24 and is carried into the cooling station. The way of working of the device that is represented in figure 1, is the following one: encristalado 1 2 heated to the convexing temperature, it is gripped by r the displaceable suction plate 3 and, with the help of the suction plate, it is carried in the bending station 10 and deposited thereon on the supporting fabric 31. During the return of the plate-sucker 3, the shape of domed 7 suction 12, it is raised and brought against the support fabric 31, and a depression is established at the level of the suction cup 12. Under the effect of the suction of the suction cup shape, the glazing is pressed with the support fabric 31 towards the concave molding surface 14. At the time of this operation, the flexible elastic fabric extends, while at the same time, upon encountering the effect of gravity of the bars 33 fixed at their ends, the active length of the fabric increases . Once that the suction operation has finished, it is deleted " the depression and the shape is released from the support fabric ^ 31 by means of a short overpressure pulse. The shape of the suction dome 12 is lowered and the frame 30 is displaced, with the pre-domed glazing, in the The end convex station 20. After the positioning of the frame 30 supporting the pre-domed glazing, the lower concave bulging shape 22 and the convex convex upper convex shape 24 are simultaneously brought into juxtaposition and thereafter pressed. glazed in the definitive form. The upper bulging shape then raises, by means of the suction effect, the finished curved glazing of the support fabric which then returns to its flat shape under the pull of the bars 33. The carrier frame 26 then comes in the form of domed 24, receives the domed glazing of the domed form and carries it into the next cooling station. The domed installation shown in the figure - 2, also operates in a similar manner and is presents in this case, in the form of a carousel with four stations, namely a loading station 37, a pre-domed station 39, a final bulging station 39 and a supplementary station 40, in which the web of Support 41 can be oriented, if it is the case. The support fabric sections 41 are supported here on the arms 42 of a turning turnstile type frame, ? at each stage, 90 ° in the direction of rotation of the arrow F '. The operations in the loading station 37, in the pre-bulging station 38 and in the station of final bulge 37, are developed in this case at the same time, which makes an embodiment of this type, particularly economic. In addition, the concept of bulging tools and the development of the procedure are the same as in the case of the form of embodiment described above, in such a way that it will be reported, in this aspect, to the description of Figure 1. Figure 3 is a sectional view, once again, of the essential features of the pre-processing station. domed The shape of the suction cup 12 is already in the upper end position, in contact through its flat surface 16 with the support fabric 31, on which the glazing rests, in a centered position. The holes 15 made in the shape of suction cup 12, assemble the molding surface 14 to the enclosure 18 in which a vacuum pump 17 is connected. In a variant, the enclosure 18 can be joined by means of a flexible depression duct, to a depression tank, in such a way that by opening a valve in this duct, a vacuum is established very quickly in the form of suction dome, thus pressing the glazing 1 with the support fabric 31 against the molding surface 14. Then, the shape of suction dome 12 is immediately put into the air and lowered again, and then glazing 1 is transported with the support fabric in the final dome station. In the case of the embodiment shown in FIG. 4, the glazing 1 is maintained, in the course of the pre-bulging operation, on the upper face at the level of the edge by means of a flat plate 45, which cooperates with the flat surface 16 of the suction-shaped form 12. The use of such a plate 45 can be advised in cases where the risk of a waviness at the edge level of the glazing is particularly high, for example in the case of particularly important spherical bulges. In addition, the shape of the suction dome is also carried out precisely as the device that is¥ r describes in figure 3. 10 In the case of particularly important spherical bulges, it may prove advantageous to assist the suction forces of the suction cup form 12, with pneumatic pressure forces acting on the top of the glazed A The device suitable for this purpose, in which the edge of the glazing 1 is maintained at the same time to prevent undulations, is shown in FIG. 5. In this case, a flat compression plate 48 is used which cooperates with the surface 16 of the shape of the suction dome 12 and which is lowered onto the glazing 1. The plate 48 is connected by means of the holes 49 to an enclosure 50, which is put under pressure by means of a pressure duct 51 at the time. in which depression is established at the level of the form of domed suction 12 by means of the enclosure 16.

In all cases, which are described, the pre-bulging stage is followed by the final bulging stage with a bulging press in the manner described above.

Claims (5)

1. CLAIMS 1.- Procedure for progressively glazing, in which the glazing heated to the bulge temperature, bulges in a horizontal position gradually in the final form in at least two successive bulging stations, are lifted by means of aspiration in the last convex station by means of a convex upper convex shape provided with suction orifices, and deposited on a movable carrier frame, characterized in that the encristalados are transported placed on a flexible mounted support fabric on a rigid carrier frame with the fabric of support and the supporting frame, stage by stage, through the installation of bulge, and bulge together with the support fabric that adapts to the shape of the encristalados.
2. 2. Method according to claim 1, characterized in that the bulging operation is carried out in two stages; the encristalados pre-bulge in the course of the first stage by a form of bulging that covers the entire surface and can be lowered on the encristalado.
3. 3. Method according to claim 1, characterized in that the bulging operation is carried out in two stages; the encristalados ones are pre-bellied in the course of the first stage by means of a concave dome shape that can be put under depression.
4. 4. Device for executing the method according to claim 1, comprising a pre-domed station, a final bending station and a carrier device that transfers the pre-domed glazing of the pre-domed station to the domed station - * • final, characterized in that the carrier device is 10 constituted by a rigid carrier frame and by a supporting fabric mounted flexibly on the carrier frame.
5. 5. Device according to claim 4, characterized in that the support fabric rests freely on two retention rods at the level of 1 two sides, opposite one another and is ballasted at their ends above the retention rods. ¥ 6.- Device according to claim 4 or 5, characterized in that, in the pre-bulging station and in the final bulging station, a The shape of the concave bulge can be lowered and raised to the plane of the support fabric, below the transport plane of the carrier device. 7. Device according to any of claims 4 to 6, characterized in that the concave convex shape is a domed form that covers the entire surface, and can be placed under vacuum by means of holes made in the molding surface. 8. Device according to claim 7, characterized in that a plate that can be lowered on the glazing, which is designed flat at least in the region of the top of the suction cup, is provided in the pre-bulging station. area of the edge of the glazing and that prevents a marginal undulation of the glazing. 9. Device according to claim 8, characterized in that, above the suction cupped form, a plate is provided that can be lowered and that can be put in overpressure by means of holes that pass through the plate. 10. Device according to any of claims 4 to 9, characterized in that the carrier frames are arranged with the support fabric on movable carriages and can be moved cyclically, step by step, through the bending installation. 11. Device according to any of claims 4 to 9, characterized in that the carrying frames are arranged on a tourniquet that transports, as a carousel, the support fabrics, step by step, through the domed installation.