KR20090030205A - Bushing device for edge roller and method for manufacturing flat glass - Google Patents

Abstract

A bushing apparatus for edge roller is provided to prevent vibration of the edge roller and to have more little crimp and to form the second bearing elastically. A bushing apparatus for edge roller contains one or more supporting members(22) inserted within a side wall(2) of a float bath apparatus(1), a pipe medium member(40) fixed to the supporting member, a bellows(28) arranged in the pipe medium member and a first bearing(16) for a drive shaft. The second bearing(18) for the drive shaft is arranged between the supporting member and the bellows. The second bearing is elastically formed. The second bearing member is resilient seal member and/or damping element.

Description

Bushing device for edge rollers and plate glass manufacturing method {BUSHING DEVICE FOR EDGE ROLLER AND METHOD FOR MANUFACTURING FLAT GLASS}

The present invention relates to a bushing device for an edge roller according to the preamble of claim 1. The invention also relates to a process for producing plate glass, in particular TFT glass.

The production of plate glass according to the float method, the so-called float glass, has long been known and is based on the patent rights of Pilkington (US 3,083,551, DE 147 19 50).

In the float method, the liquid glass guided by the grooves from the working bath is allowed to flow over a bath of molten metal, usually tin. The mass flow rate of the glass is controlled by the movable slide, in particular by the control of the mass flow rate, the glass thickness is controlled. A cast lip is placed behind the slide when viewed in the flow direction of the glass, from which the glass melt continuously flows onto the metal bath, where the glass melt is molded into a dimensionally stable glass strip and solidified. Then, the solidified glass strip is separated from the metal bath.

Float baths are generally arranged in a float bath housing divided into seven or eight float bath portions, so-called bays.

Float glass, generally having a thickness of less than 1.5 mm, produced in the above-described manner is a thin glass substrate, in particular a flat panel display such as a plasma display (PDP = Plasma Display Panel), a field emission display (FED), a TFT To manufacture liquid crystal displays (TFT = Thin Film Transistor), STN-Liquid Crystal Display (STN = Super Twisted Nematic), Plasma Supported Liquid Crystal Display (PALC = Plasma Assisted Liquid Crystal), Electro-Brightness-Display (EL) and the like Or to manufacture thin film solar cells.

In the case of flat panel displays, depending on the type of display, a thin layer of liquid crystal bonding is inserted between the two glass plates or a dielectric layer is provided on the front or back of the rear or front plate, respectively. The dielectric layer constitutes cells containing phosphorus.

In this case, it is important that the layer thickness of the liquid crystal layer or the thickness of the dielectric layer is accurately maintained, so that color modulation or similarity deviation does not occur, particularly in the case of a large display. This condition is more important because the layer thickness, which is recently about 30 μm, is getting smaller and the display is getting bigger and larger.

The surface quality of float glass is degraded by surface defects called top-specks. The top-spec appears on the glass strip by precipitation by Sn particles and SnO ₂ particles when using a tin bath. The atmosphere above the float bath contains a residual amount of oxygen, although the forming gas (typically 10% H ₂ , 90% N ₂ ) flows through the interior space, and this oxygen penetrates into the tin bath, where the SnO ₂ − To form particles. As the temperature of the bath increases, tin particles and tin oxide particles vaporize to enrich the atmosphere so that tin particles and tin oxide particles can be deposited on the glass strip.

Another adverse effect is due to the so-called top roller, which can cause crimp in the glass strip.

Top rollers, also referred to as edge rollers, have wheels lying on the edges of the glass strip, which wheels are connected to the drive shafts, which are guided out through the walls of the float bath apparatus by an outer tube, whereby the edges A drive and support device for the roller is arranged. The wheel, drive shaft and outer tube are generally cooled. The edge rollers must be movable in the vertical and horizontal directions to align the wheel with respect to the glass strip. The bushing device must take these requirements into account and ensure sufficient sealing so that on the one hand the forming gas inside the float bath device cannot leak out and on the other hand air, and therefore oxygen, is the internal space of the float bath device. It must not be able to penetrate into.

US 3,709,673 is known for edge rollers supported on a table arranged outside of a float bath device. The edge roller has a drive shaft, which drive shaft is disposed in the stationary tube, which stationary tube extends into the interior space through the side wall of the float bath device. Due to the large gap between the wheel of the edge roller and the support point on the table, the free end of the edge roller on which the wheel is fixed may vibrate, which may cause crimping of the glass strip.

DE-AS 1 596 589 discloses an edge roller supported on a bearing in the side wall of a float bath vessel. Here, since the bearing is formed at the same time as a seal for the outside air, the outside air cannot penetrate into the protective gas atmosphere inside the float bath housing. This support has the disadvantage that the position of the edge roller is fixed, so that alignment and adjustment with respect to the glass strip are impossible.

JP 08-277 130 A discloses an edge roller with a bushing device, which has a tube as a support member and a shrinkage and bellows connected to it externally, arranged in the side wall of the float bath device. The bearing is arranged at the outer end of the bellows. The edge roller is sealed and movable vertically due to the shrinkage and the free space in the tube, in particular pivotable about a horizontal axis for the necessary alignment to the glass strip. However, even with this bushing device, since the vibration of the edge roller cannot be prevented, the glass strip has a crimp.

Based on JP 08-277 130, the problem of this invention is providing the bushing apparatus for edge rollers which prevents the vibration of an edge roller.

Moreover, the subject of this invention is providing the manufacturing method of the plate glass which has less crimp.

The problem is solved by a bushing device, wherein a second bearing for the shaft is disposed between the support member and the bellows, and the second bearing is elastically formed.

The first bearing of the drive shaft is preferably arranged on or in the drive unit.

By means of a further second bearing arranged in a sealing manner on the side wall, since the free length of the edge roller is significantly reduced, the vibration of the wheel of the edge roller and thus the crimp of the glass strip is significantly reduced.

The elasticity of the second bearing allows the pivoting of the drive shaft about the vertical axis and the horizontal axis, so that the wheel can be aligned with respect to the position of the glass strip. Thus, the point of rotation of the drive shaft is arranged in the second bearing.

The inner diameter of the support member, which may for example be a tubular part, is set to provide sufficient space for the pivoting movement of the drive shaft. The connecting side portion of the drive shaft is guided through the bellows, which due to its elasticity is in a pivoting motion.

The second bearing preferably has one or more elastic bearing members. The second elastic bearing member is preferably a sealing member, which has the advantage that there is an additional seal in the immediate vicinity of the side wall. The additional seal effectively prevents the introduction of air, and therefore oxygen, into the interior space of the float bath housing.

The second bearing member is also formed as a damping member for at least attenuating or in particular preventing vibration of the edge roller, which sometimes occurs.

The second bearing member not only supports the shaft, but also allows the shaft to pivot in a limited manner, and performs sealing and / or damping of the shaft.

Preferably, the second bearing member is disposed in the tube intermediate member. The tube intermediate member is preferably rigidly connected with the support member. Thus, the second bearing point is fixedly arranged, whereby the mobility of the drive shaft is determined by the second bearing member.

This need for the second bearing member is met by a ring tube comprising a filler made of elastic fiber material according to a particular embodiment. This embodiment has the advantage that the ring tube lies in a sealed manner on the inner surfaces of the drive shaft and the tube intermediate member. The elastic fiber material allows for mobility for alignment of the drive shaft and damping of the drive shaft when vibration of the edge roller occurs.

Preferably the ring tube consists of a silicate fabric. As the fiber material, a ceramic fiber material made of aluminum silicate fibers is particularly preferably used.

The elastic second bearing member is in particular axially fixed by the sleeve. Because of this, the second bearing member cannot be moved inside the tube intermediate member during operation. In particular, for the adjustment to the glass strip, the second bearing member cannot be moved even if the edge roller has to be moved in the axial direction.

At the outer end of the bellows, one or more sealing devices, preferably including packing boxes, are preferably arranged.

The packing box preferably has a winding of a band of silicate material. This ensures good sealing on the one hand and thermal insulation on the other.

In addition, the support member may be embodied as a double wall and may include insulation. Sealing screens can also be implemented with double walls and include insulation to prevent heat loss and contribute to stable temperatures inside the float bath housing.

Preferably, at least one seal is disposed between the tube intermediate member and the bellows. The seal preferably consists of a graphite ring.

In particular, the bellows is pressed against the tube intermediate member by the tightening device, so that the sealing is further improved. As a result, the seals disposed therebetween are correspondingly pressed.

In order to further improve the vibration characteristics, the tube intermediate member has a fixing device for fixing to the side wall of the float bath device. Thus, a stable implementation is performed that is not sensitive to vibration as a whole.

The method for producing plate glass is characterized in that an edge roller supported by a vibration damping method is used. For this reason, the crimp of the glass strip on which an edge roller acts is reduced significantly, and the quality of plate glass improves.

The edge roller is supported in a vibration damping manner at the end of the drive shaft facing the wheel of the edge roller. The vibration damping support is preferably arranged in the front half of the drive shaft, particularly preferably adjacent to the side wall of the device. This additional bearing, in which the edge roller is supported in a vibration damping manner, reduces the occurrence of vibration with large amplitude, since this additional bearing is provided closer to the free end of the edge roller than the first bearing.

The method according to the invention is provided for the production of TFT glass. The method can also be used for thick glass, in particular for glass having a thickness of more than 5 mm.

The process according to the invention is particularly suitable for the production of borosilicate glass, alkali free glass, aluminosilicate glass, aluminosilicate silicate glass and precursor glass for glass ceramics.

The method is characterized by the desired composition (all amounts indicated below are by weight based on oxide; SiO ₂ 70-85, B ₂ O ₃ 7-13, Na ₂ O + K ₂ O + Li ₂ O 3-8, Preparation of borosilicate glass with MgO + CaO + SrO 0-3, Al ₂ O ₃ 2-7, for example for refractory applications, the desired composition (SiO ₂ 50-70, B ₂ O ₃ ≦ 15, Al ₂ O ₃ 10-25, MgO 0-10, CaO 0-12, SrO 0-12, BaO 0-15, with MgO + CaO + SiO + BaO 8-26, ZnO 0-10, ZrO ₂ 0-5, TiO ₂ 0-5, preparation of alkali-free alumino (boro) silicate glass with SnO ₂ 0-2), eg, given composition (SiO ₂ > 55-65, B ₂ O ₃ 5-11, Al ₂ O ₃ > 14-25, MgO 0-8, CaO 0-8, SrO 0-8, BaO ≤ 10, except MgO + CaO + SrO + BaO 8-21, ZnO 0-5, ZrO ₂ 0-2, TiO ₂ 0- 3, SnO ₂ 0-2, in particular SiO ₂ > 58-65, B ₂ O ₃ > 6-10.5, Al ₂ O ₃ > 14-25, MgO 0 to less than 3, CaO 0-9, BaO> 3- 8, provided that MgO + CaO + BaO 8-18, ZnO 0 to less than 2, no As ₂ O _3, no Sb ₂ O ₃ , preferably no Zn oxide, no Ce oxide, no Zr oxide, no Ti oxide) Diss Ray is particularly suitable for the manufacture of glass.

In addition, the present method has a predetermined composition (SiO ₂ 55-69, Al ₂ O ₃ 19-25, Li ₂ O 3-5, Na ₂ O 0-1.5, K ₂ O 0-1.5, Na ₂ O + K ₂ O 0.2-2, MgO 0.1-2.2, CaO 0-15, SrO 0-1.5, BaO 0-2.5, Less than MgO + CaO + SrO + BaO 6, ZnO 0-1.5, TiO ₂ 1-5, ZrO ₂ 1-2.5, SnO ₂ 0 to less than 1, Preparation of different green glass for glass ceramics with TiO ₂ + SrO ₂ + SnO ₂ 2.5-5, P ₂ O ₅ 0-3, or desired compositions (SiO ₂ 55-75, Al ₂ O ₃ 15-30, Li ₂ O 2.5-6, Less than Na ₂ O + K ₂ O 6, Less than MgO + CaO + SrO + BaO 6, B ₂ O ₃ 0 to less than 4, Preparation of a glass ceramic precursor glass with TiO ₂ + ZrO ₂ 2, or a predetermined composition (SiO ₂ 60-72, Al ₂ O ₃ 18-28, Li ₂ O 3-6, Na ₂ O + K ₂ O 0.2-2, Less than MgO + CaO + SrO + BaO 6, ZnO 0-1.5, B ₂ O ₃ 0 to less than 4, SnO 0.1-1.5, Particularly suitable for the preparation of glass ceramic precursor glass with TiO ₂ + ZrO ₂ 2, P ₂ O ₅ 0-3, F 0-2).

According to the present invention, a bushing device for an edge roller is provided, which prevents vibration of the edge roller.

1 is a vertical sectional view of the edge of a floating bath device with a bushing device of an edge roller;

FIG. 2 is a cross sectional view of the first and second bearing point regions of the bushing device with the drive shaft pivoted relative to the position of FIG. 1; FIG.

3 is an enlarged perspective view of the second bearing point region;

4 is a vertical sectional view of the bushing device according to FIG. 1 excluding the edge rollers.

<Explanation of symbols for the main parts of the drawings>

1: float bath device 40: tube middle member

2: side wall 44: second bearing member

10: edge roller 46: ring tube

11: wheel 48: filling material

12: drive shaft 50: sealing device

16: first bearing 52: packing box

18: second bearing 54: band

20: bushing device 70a, 70b: graphite ring

22: support member 80: fixing device

24: sealing screen

26: heat insulation

28: bellows

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail.

1 schematically shows the right part of a float bath device 1 with a bottom wall 3 and a side wall 2. Inside the float bath device 1 a bath made of liquid metal 4, in particular tin, is arranged, a glass strip 5 is arranged on the bath, and an edge roller 10 at the edge 6 of the glass strip. Wheels 11 act. The edge roller 10 has a rotatable, cooled drive shaft 12, which extends in the stationary outer tube 13. A slide sealing ring 9 is arranged at the end of the outer tube 13 in the region of the rotating wheel 11.

The drive shaft 12 is connected to the drive device 14 outside the float bath device 1, which can be placed on the floor 8 or alternatively suspended on the ceiling, for example. The first bearing 16 of the drive shaft 12 is arranged in the drive device 14.

The bushing device 20 for the edge roller 10 has a support member 22, which is inserted into the side wall 2. In the figure shown here, the support member 22 consists of a tube connection, the inner diameter of which is much larger than the outer diameter of the tube 13 of the edge roller 10.

The support member 22 is externally connected with a sealing screen 24, which sealingly lies on the outer surface of the side wall 2. The inner diameter of the sealing screen 24 corresponds to the inner diameter of the support member 22. The sealing screen 24 is formed of a double wall and has a heat insulator 26 therein.

In the sealing screen 24 a tube intermediate member 40 is arranged, which has a fixing device 80 on its upper surface. The tube intermediate member 40 is further secured to the outer surface of the side wall 2 of the float bath device 1 by the fixing device 80 to reduce vibration.

The second bearing 18 having the elastic bearing member 44 is disposed in the inner space of the tube intermediate member 40. The second bearing member 44 is described in detail with reference to FIGS. 3 and 4.

The tube intermediate member 40 has a flange 41, on which the first flange 30 of the bellows 28 rests. The two flanges 41, 30 are connected by a tightening device 74.

Between the two flanges 41 and 30, a graphite ring 70a is arranged as a sealing ring, which is pressed by the fastening device 74.

The bellows 28 has a second flange 32 at the right end, and on the outer surface of the flange 32 a flange 55 of the sealing device 50 is placed, the flange 55 being a packing box 52. ).

As described in connection with FIG. 4, the packing box 52 consists of a winding of the silicate band 54 shown only schematically in FIG. 1. Between the two flanges 55, 32 another seal in the form of a graphite ring 70b is arranged.

Since the inner diameters of the support member 22, the sealing screen 24, the tube intermediate member 40 and the bellows 28 are larger than the outer diameter of the outer tube 13, it is possible to move and / or pivot the drive shaft 12. Sufficient space is provided.

2 shows the area of the bellows 28 and the tube intermediate member 40 in an enlarged cross sectional view. The drive shaft 12 with the outer tube 13 is pivoted by an angle α with respect to the horizontal line 92. The longitudinal axis of the outer tube 13 is indicated at 94. The wheel 11 (not shown) has an inclined position.

The turning point 90 lies in the second bearing 18. Since the tube intermediate member 40 is fixedly mounted, the pivot of the tube 13 causes deformation of the bearing member 44. Since the bearing member 44 is formed elastically, the turning process can be made without any problem and without interruption of the sealing action of the bearing member 44. Since the packing box 52 does not allow this deformation, a turning to the top of the sealing device 50 is made, which is possible due to the elastic formation of the bellows 28.

3 shows the front region of the bushing device 20 in an enlarged perspective view. The support member 22 consists of a box-shaped insert in the embodiment shown, which insert is inserted into the corresponding opening of the side wall 2 of the float bath device 1. A sealing screen 24 is disposed in front of the support member 22 to seal the opening in the side wall 2.

An intermediate tube 40 is connected to the sealing screen 24, and the intermediate tube 40 has a flange 41, and a fixing pin 72 protrudes to the right in the horizontal direction. . A corresponding hole is arranged in the first flange 30 of the bellows 28 and the pin 72 is inserted into the hole during assembly.

A second bearing member 44 is disposed inside the tube middle member 40, and the bearing member 44 is formed of a ring tube 46, and a filler 48 made of a heat insulating material in the form of silicate fibers in the ring tube. ) Is placed. Due to this, the second bearing member 44 obtains elastic properties, which enable the pivoting of the drive shaft 12 of the edge roller 10, as exemplarily shown in FIG. 2. The second bearing member 44 rests on the sleeve 42 and is axially fixed to the sleeve by ring collars 43a and 43b.

4 shows a cross-sectional view of the entire bushing device 20. The sleeve 42 has a ring collar 43a on the left side and a ring collar 43b on the right side, which prevents the second bearing member 44 from displacing in the axial direction.

The support member 22 is implemented as a double wall and includes a heat insulator 26.

The packing box 52 extends in the interior space of the bellows 28. A winding consisting of a silicate band 54 is arranged in a ring-shaped housing 51 with a front collar 53, and a pressing ring 57 is inserted from the outside onto the winding. The flange 32 of the bellows 28 is connected in a sealing manner with the flange 55 of the packing box 52 via the graphite ring 70b by the tightening device 60. By means of another fastening device 56, which consists of a screw 59 which is spring-supported to the flange 58 and fixed to the flange 55, the packing box 52 is pressurized and a certain seal is made.

A tightening device 74 is shown connecting the tube intermediate member 40 and the bellows 28. The tightening device 74 has two tightening levers 76, by which the pipe intermediate member 40 and the two flanges 30 and 41 of the bellows 28 are pressed against each other. On the upper surface of the tube intermediate member 40 an additional fixing device 80 is arranged, which is fixed to the outer surface of the side wall 2.

Claims (19)

Bushing device 20 for an edge roller 10 comprising a drive shaft 12 and a wheel 11, at least one support member 22 insertable into the side wall 2 of the float bath device 1, said support For edge rollers comprising a tube intermediate member 40 fixed to member 22, a bellows 28 disposed on tube intermediate member 40, and a first bearing 16 for drive shaft 12. In the bushing device, An edge roller, characterized in that the second bearing 18 for the drive shaft 12 is disposed between the support member 22 and the bellows 28, the second bearing 18 being elastically formed. Bushing device for. 2. Bushing device according to claim 1, characterized in that the second bearing (18) comprises at least one elastic second bearing member (44). 3. Bushing device according to claim 1 or 2, characterized in that the second bearing member (44) is an elastic sealing member and / or a damping member. 4. Bushing device according to claim 2 or 3, characterized in that the second bearing member (44) is arranged in the tube intermediate member (40). The second bearing member 44 has a ring tube 46, in which the filler 48 made of an elastic fiber material is disposed. Bushing device for the edge roller, characterized in that. 6. Bushing device according to claim 5, characterized in that the ring tube (46) consists of a silicate fabric. The bushing device for an edge roller according to claim 5 or 6, wherein the elastic fiber material is made of a ceramic fiber material. 8. Bushing device according to any one of the preceding claims, characterized in that the second bearing member (44) is axially fixed by a sleeve (42). 9. Bushing device according to any one of the preceding claims, characterized in that at least one sealing device (50) is arranged at the outer end of the bellows (28). 10. Bushing device according to claim 9, characterized in that the sealing device (50) comprises a packing box (52). 11. Bushing device according to claim 10, characterized in that the packing box (52) comprises a winding of a band (54) made of silicate material. 12. Bushing device according to any one of the preceding claims, characterized in that the support member (22) is implemented as a double wall and comprises a heat insulator (26). 13. Bushing device according to any one of the preceding claims, characterized in that the support member (22) comprises a sealing screen (24) lying on the outer surface of the side wall (2). 14. Bushing device according to claim 13, characterized in that the sealing screen (24) is implemented as a double wall and comprises a heat insulator (26). 15. The bushing device according to any one of the preceding claims, characterized in that a seal is arranged between the tube intermediate member (40) and the bellows (28). 16. The bushing device according to claim 15, wherein the seal is a graphite ring (70a, 70b). 17. Bushing device according to any one of the preceding claims, characterized in that the bellows (28) is connected with the tube intermediate member (40) by means of a tightening device (74). 18. The tube intermediate member (40) according to any one of the preceding claims, characterized in that the tube intermediate member (40) comprises a fixing device (80) for securing to the side wall (2) of the float bath device (1). Bushing device for edge rollers. A method of making plate glass, wherein a glass melt flows onto a bath of liquid metal, the glass melt is formed into a glass strip, the shaped glass strip is raised from a metal bath, and the glass is formed during the molding of the glass strip. A method for producing plate glass using an edge roller for guiding strips, the method comprising: using an edge roller supported in a vibration damping manner.