Glass forming equipment

Abstract

A glass forming device (1) comprises: a forming body (4) which forms a glass ribbon (3) from molten glass (2) by an overflow downdraw method; supporting bricks (6, 7) which support the longitudinal end of the upper portion of the forming body (4) from below and press the lower portion of the forming body (4) along the longitudinal direction; a pressing device (8) which presses the supporting bricks (6) toward the side of the forming body (4); and a forming furnace (9) which accommodates the forming body (4) therein, wherein the glass forming device (1) has a structure in which the pressing device (8) is fixed to the forming furnace (9).

Description

Technical Field

[0001] The present invention relates to glass forming apparatus. Background Art

[0002] As is well known, one of the methods for manufacturing a glass sheet is an overflow down-draw method. Patent Document 1 discloses an example of a manufacturing facility capable of performing the overflow down-draw method.

[0003] The manufacturing equipment disclosed in Patent Document 1 comprises: a wedge-shaped forming body that forms a glass ribbon (a sheet glass plate SG in this document) from molten glass; a pair of supporting bricks (a first supporting member 410 and a second supporting member 420 in this document) that support the forming body while sandwiching the forming body from one end side and the other end side in the longitudinal direction of the forming body; and a pressing device (a pressurizing device 422 in this document) that presses one of the pair of supporting bricks toward the forming body side.

[0004] In the above-mentioned manufacturing equipment, as the pressing device presses the support bricks, compressive stress in the longitudinal direction acts on the formed body, thereby suppressing creep deformation of the formed body caused by its own weight, the weight of the molten glass, etc.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2012 / 132309 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] In manufacturing equipment such as the one described above, the formed bodies and the forming furnaces that house them are sometimes moved to adjust their positions before or during operation. In this case, if the pressing device is fixed to, for example, a building, the position of the pressing device must be changed according to the movement of the formed bodies. This makes the adjustment of the positions of the formed bodies and the like cumbersome. Furthermore, a mechanism is required to change the position of the pressing device, making the equipment structure more complex.

[0010] In view of the above circumstances, a technical problem to be solved is to provide a manufacturing apparatus that can easily adjust the position of a formed body, etc., while suppressing creep deformation of the formed body.

[0011] Solutions to Problems

[0012] A glass forming device for solving the above-mentioned problems comprises: a forming body, which forms a glass ribbon from molten glass using an overflow down-draw method; supporting bricks, which support the longitudinal end of the upper part of the forming body from below and press the lower part of the forming body along the longitudinal direction; a pressing device, which presses the supporting bricks toward the side of the forming body; and a forming furnace, which accommodates the forming body inside. The glass forming device is characterized in that the pressing device is fixed to the forming furnace.

[0013] In this glass forming apparatus, the pressing device is fixed to the forming furnace, so it moves along with the furnace. Therefore, when adjusting the position of a formed body, etc., there is no need to reposition the pressing device, making the operation easier. Furthermore, since there is no need for a mechanism to reposition the pressing device, the equipment structure can be simplified.

[0014] In the above structure, the forming furnace preferably includes a refractory brick wall surrounding the formed body, a heating device for heating the formed body from the side, and a frame surrounding the refractory brick wall and the heating device and fixing the pressing device.

[0015] In this way, when the pressing device presses the support bricks toward the formed body, the frame absorbs the reaction force of the pressing when the pressing device presses the support bricks toward the formed body while suppressing creep deformation of the formed body. It should be noted that the frame surrounds both the refractory brick wall and the heating device, and the frame is arranged outside both, so that the frame can also be prevented from being damaged by heat.

[0016] In the above structure, it is preferred that the supporting bricks are arranged on both one end side and the other end side in the longitudinal direction of the formed body, and the pressing device is configured to press only one of the two supporting bricks, and the other of the two supporting bricks is held on the frame.

[0017] Thus, the pressing device is configured to press only one of the two supporting bricks, thereby further simplifying the structure of the device. In addition, the other supporting brick is held by the frame, thereby enabling the frame to absorb the reaction force.

[0018] In the above-described configuration, the frame preferably includes a pair of main frames disposed corresponding to both ends in the longitudinal direction of the formed body, and a rod spanning the pair of main frames.

[0019] In this way, the reaction force can be appropriately absorbed by the rod. Moreover, by arranging the rod on the frame, the risk of plastic deformation of the frame when absorbing the reaction force can be reduced to a minimum.

[0020] In the above-described structure, it is preferable that the rods are arranged on both sides of the formed body with the formed body interposed therebetween.

[0021] In this manner, the rods disposed on both sides of the formed body (one side and the other side sandwiching the formed body) can absorb the reaction force in a well-balanced manner.

[0022] In the above-mentioned structure, it is preferable that the rod extends parallel to the longitudinal direction of the formed body.

[0023] With this configuration, the direction of the pressing force applied by the pressing device when pressing the supporting brick is the same as the direction in which the rod extends, and thus the frame can efficiently absorb the reaction force.

[0024] In the above configuration, the pressing device preferably includes a lever mechanism configured to press the supporting brick using a force applied to a force point and amplified to act on the force point, and the rod is preferably arranged at the same height as a fulcrum of the lever mechanism.

[0025] In this way, the pressing device has a lever mechanism, and the pressing device uses the force acting on the action point of the lever mechanism to press the supporting brick, which is advantageous in that the supporting brick can be pressed with a large force. In addition, the rod is arranged at the same height as the fulcrum of the lever mechanism, so that the force in the direction of displacement can be efficiently absorbed.

[0026] Effects of the Invention

[0027] According to the glass forming apparatus of the present invention, creep deformation of a formed body can be suppressed and position adjustment of the formed body and the like can be easily performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a side view showing a glass forming apparatus.

[0029] Figure 2 It shows Figure 1 Cross-sectional view of section AA in FIG.

[0030] Figure 3 This is a side view showing a modified example of the glass forming apparatus.

[0031] Figure 4 It is a side view showing another modified example of the glass forming apparatus.

[0032] Figure 5 This is an exploded view showing a partial configuration of another modified example of the glass forming apparatus. DETAILED DESCRIPTION

[0033] Hereinafter, a glass forming apparatus according to an embodiment will be described with reference to the drawings. It should be noted that the X direction, Y direction, and Z direction shown in the drawings referred to in the description of the embodiment are directions orthogonal to each other.

[0034] like Figure 1 as well as Figure 2 As shown, the glass forming device 1 (hereinafter referred to as simply the forming device 1) includes: a forming body 4, which forms a glass ribbon 3 from a molten glass 2; a supply pipe 5, which supplies the molten glass 2 to the forming body 4; a pair of supporting bricks 6, 7, which support the forming body 4; a pressing device 8, which presses the supporting brick 6 of the two supporting bricks 6, 7 toward the side of the forming body 4; and a forming furnace 9, which accommodates the forming body 4 inside.

[0035] The forming body 4 and the two supporting bricks 6 and 7 are arranged inside the forming furnace 9. The forming furnace 9 comprises: a frame 10; a refractory brick wall 11 (only Figure 2 ), which is arranged on the inner side of the enclosure based on the frame 10 and is used to surround the formed body 4; and a heating device 12 (only in Figure 2 (shown in the figure), which is arranged between the frame 10 and the refractory brick wall 11.

[0036] The frame 10 has a rectangular box-shaped exterior that is long in the X direction and also functions as an outer shell. The frame 10 comprises a pair of main frames 10a and 10b, each positioned corresponding to the longitudinal ends of the formed body 4; and beams 10c and rods 10d, which are mounted between the main frames 10a and 10b. The frame 10 is made of metal, specifically carbon steel, stainless steel, heat-resistant steel, or the like. The Young's modulus of the metal constituting the frame 10 is preferably 80 GPa or higher, and more preferably 150 GPa or higher.

[0037] The two main frames 10a and 10b each have a skeleton structure made by combining plates and rods extending in the X, Y, and Z directions. The lower parts of the two main frames 10a and 10b respectively hold the support bricks 6 and 7. The beams 10c and rods 10d extend parallel to the longitudinal direction of the molded body 4.

[0038] There are at least four beams 10 c , and the four beams 10 c correspond to four sides extending in the X direction of the rectangular parallelepiped of the outer shape of the frame 10 .

[0039] The rods 10d are arranged on both sides of the formed body 4, sandwiching the formed body 4. That is, a pair of rods 10d are arranged at intervals along the Y direction. The pair of rods 10d, 10d are each arranged at a height between the beam 10c arranged on the upper side and the beam 10c arranged on the lower side of the four beams 10c. The height at which the pair of rods 10d, 10d are arranged becomes the same height as the fulcrum P3 of the lever mechanism 13 described later. It should be noted that, as in the present embodiment, when there is a fulcrum P3 at a height between the upper end and the lower end of the frame 10 (here, the height between the beam 10c located on the upper side and the beam 10c located on the lower side), by aligning the rod 10d with the height of the fulcrum P3, the rod 10d effectively performs its function (details will be described later). The pair of rods 10d, 10d are each fixed to the sides of the two main frames 10a, 10b. That is, the two main frames 10a and 10b are sandwiched between the pair of rods 10d and 10d. The cross-sectional shape of the rod 10d (the shape of the cross section perpendicular to the X direction) may be any shape, and for example, a rectangular or circular shape.

[0040] As a variation of this embodiment, the rods 10d are not limited to a single pair; multiple pairs may be provided on the frame 10. Specifically, in addition to the pair of rods 10d, 10d positioned at the same height as the fulcrum P3 of the lever mechanism 13, the frame 10 may also include one or more pairs of rods 10d, 10d positioned at different heights than the fulcrum P3. Furthermore, each rod 10d need not necessarily be fixed to the sides of the two main frames 10a, 10b. For example, each rod 10d may be fixed between the two main frames 10a, 10b, sandwiching the rods 10d. In this case, one end of each rod 10d is connected to the main frame 10a, and the other end is connected to the main frame 10b.

[0041] The refractory brick wall 11 is composed of a plurality of refractory bricks and is formed into a room-like shape, covering the formed body 4 from above and laterally. The refractory brick wall 11 includes a pair of plate-shaped refractory bricks 11a, 11a arranged at intervals in the Y direction. The pair of plate-shaped refractory bricks 11a, 11a are arranged on either side of the formed body 4, sandwiching the formed body 4. Each plate-shaped refractory brick 11a laterally contacts the two support bricks 6, 7. The refractory brick wall 11 is held to the frame 10 by a heat-insulating member (e.g., refractory bricks) (not shown).

[0042] The heating device 12 can heat the formed body 4 from the side via the plate-shaped refractory bricks 11a. The heating devices 12 are arranged on both sides of the formed body 4 with the formed body 4 sandwiched in the middle. Moreover, a plurality of heating devices 12 are arranged along the length direction of the formed body 4 on both sides with the formed body 4 sandwiched in the middle. Each of the plurality of heating devices 12 is in contact with the plate-shaped refractory bricks 11a in a state of being mounted on a beam (beams other than the above-mentioned four beams 10c) that is provided on the frame 10 and not shown. In this embodiment, a plate heater is used as the heating device 12. Of course, this is not limited to this. As a modification of this embodiment, a heater other than a plate heater may also be used as the heating device 12.

[0043] An opening 9a that connects the inside and outside of the furnace is formed in the forming furnace 9. The opening 9a is formed at a position corresponding to the support brick 6, and a part of the surface of the support brick 6 is exposed in the opening 9a.

[0044] The molded body 4 is a molded body for overflow down-drawing having a wedge-shaped cross-section (a cross-section perpendicular to the X direction) and is made of dense zircon, alumina-based, zirconia-based, or other refractory bricks.

[0045] After the forming body 4 causes the molten glass 2 to flow into the groove (shown in the figure) formed on the upper part of the forming body 4, the molten glass 2 overflowing from the groove to both sides is caused to flow along a pair of side surfaces 4b, 4b (at the bottom of the forming body 4) Figure 1 The molten glass 2 flowing down the two side surfaces 4b and 4b is then combined at the lower end 4c of the forming body 4. A glass ribbon 3 is formed from the molten glass 2 combined at the lower end 4c.

[0046] The length of the molded body 4 is, for example, 1500 mm to 6000 mm. The frame 10 described above is effective when a large molded body 4 is provided. Therefore, the preferred lower limit of the length of the molded body 4 is 2000 mm or greater, 2500 mm or greater, 3000 mm or greater, 3500 mm or greater, and particularly preferably 4000 mm or greater.

[0047] The supply pipe 5 supplies the molten glass 2 to the forming body 4 from one end in the longitudinal direction of the forming body 4 .

[0048] A pair of support bricks 6 and 7 each support the longitudinal ends of the formed body 4 from below and press the formed body 4 in the longitudinal direction. Specifically, the longitudinal ends of the upper portion of the formed body 4 rest on the upper surfaces of the pair of support bricks 6 and 7, thereby supporting the formed body 4 in a suspended state. Furthermore, each pair of support bricks 6 and 7 has a pressing surface S for pressing the formed body 4. These pressing surfaces S are in surface contact with the longitudinal end surface 4d of the lower portion of the formed body 4, pressing the formed body 4 in the longitudinal direction. It should be noted that the pressing surfaces S of the support bricks 6 and 7 and the end surface 4d of the formed body 4 are both vertical planes, but may also be inclined or curved. Of the two support bricks 6 and 7, support brick 7 is held immovable in the longitudinal direction of the formed body 4. Meanwhile, support brick 6 can move toward the formed body 4 as the pressing device 8 presses against it. In this embodiment, support brick 7 is fixed to the frame 10, while support brick 6 is held in the frame 10 so as to be movable in the longitudinal direction of the formed body 4.

[0049] The pressing device 8 is positioned on the side opposite the supply pipe 5 in the longitudinal direction of the formed body 4. The pressing device 8 presses only the support brick 6 of the pair of support bricks 6 and 7. Furthermore, as the pressing device 8 presses the support brick 6, it applies a longitudinal compressive stress to the formed body 4 sandwiched between the two support bricks 6 and 7. This suppresses creep deformation caused by the weight of the formed body 4, etc.

[0050] The pressing device 8 includes a lever mechanism 13 that amplifies the force applied to the force point P1 and applies it to the force point P2; and an air cylinder 14, which serves as an actuator and generates the force applied to the force point P1. The pressing device 8 uses the force applied to the force point P2 to press the support brick 6.

[0051] In this embodiment, the air cylinder 14 is used as the actuator, but the present invention is not limited to this. As a modification of this embodiment, a hydraulic cylinder, a mechanical jack, a ball screw mechanism, etc. may be used instead of the air cylinder 14. In addition, a counterweight may be used as the force generation source instead of the actuator.

[0052] The lever mechanism 13 includes an arm member 15 having a pressure receiving portion 15 a and a pressing portion 15 b , and a holding member 17 that holds the arm member 15 while allowing the arm member 15 to swing about a fulcrum P3 .

[0053] The arm member 15 is elongated in one direction extending vertically. The pressure-receiving portion 15a at the upper end of the arm member 15 receives the force generated by the air cylinder 14 and corresponds to the force point P1. Meanwhile, the pressing portion 15b at the lower end of the arm member 15 presses the support brick 6 and corresponds to the action point P2. The distance L1 from the fulcrum P3 to the force point P1 is longer than the distance L2 from the fulcrum P3 to the action point P2. Distance L1 is preferably 1.2 to 3.0 times the distance L2.

[0054] The pressing portion 15b of the arm member 15 is formed of a disk rotatable about a shaft 16. Specifically, the pressing portion 15b is rotatably held at the lower end of the arm member 15 by the shaft 16. The shaft 16 extends parallel to a rod 17a (described later) provided in the holding member 17.

[0055] The holding member 17 is fixed to the outer surface 10e of the frame 10. That is, the lever mechanism 13 is fixed to the outer surface 10e of the frame 10 via the holding member 17. The holding member 17 includes a rod 17a extending in the Y direction and penetrating the arm member 15. The rod 17a serves as the central axis of the swing of the arm member 15 and also serves as the fulcrum P3 of the lever mechanism 13.

[0056] The end of the cylinder 14 (the end opposite to the front end of the piston rod) is fixed to the pressure-receiving portion 15a of the arm member 15. The cylinder 14 is arranged between the pressure-receiving portion 15a of the arm member 15 and the outer surface 10e of the frame 10 at a position above the rod 17a (fulcrum P3) provided on the retaining member 17.

[0057] The piston rod of the air cylinder 14 is in contact with the outer surface 10e of the frame 10. The piston rod extends in a direction perpendicular to the longitudinal direction of the arm member 15, and its front end (the portion in direct contact with the outer surface 10e of the frame 10) is formed into a convex curved surface.

[0058] The center of gravity of the cylinder 14 is located on the side opposite to the outer surface 10e of the frame 10 with respect to the rod 17a (support point P3) in the X direction. Figure 1 The torque of the force (clockwise).

[0059] When the air cylinder 14 operates, its output, or piston rod, presses against the outer surface 10e of the frame 10. The resulting reaction force applies force to the pressure-receiving portion 15a of the arm member 15. The force applied to the pressure-receiving portion 15a is amplified by the lever mechanism 13, creating a force that presses against the support brick 6. Furthermore, the moment of force generated by the weight of the air cylinder 14 further compresses the support brick 6.

[0060] The height at which the pair of rods 10d and 10d are arranged does not necessarily have to be the same as the height of the fulcrum P3 of the lever mechanism 13, and may differ therefrom. From the perspective of efficiently absorbing the reaction force, the height at which the pair of rods 10d and 10d are arranged is preferably 200 mm or less, more preferably 150 mm or less, and even more preferably the same as the height of the fulcrum P3 of the lever mechanism 13.

[0061] Here, as described above, the pair of rods 10d, 10d are arranged at the same height as the fulcrum P3 of the lever mechanism 13. Consequently, when the pressing device 8 presses the support brick 6, the rods 10d provide the following effect. When the support brick 6 is pressed by the pressing device 8, a force (reaction force) acting away from the molded body 4 acts at a portion of the frame 10 at a height corresponding to the fulcrum P3. However, this force can be efficiently absorbed by the rods 10d, which are arranged at the same height as the fulcrum P3.

[0062] The holding member 17 and the cylinder 14 included in the lever mechanism 13 are located outside the forming furnace 9. Meanwhile, the arm member 15 included in the lever mechanism 13 is arranged so as to extend across the interior and exterior of the forming furnace 9 through the opening 9a of the forming furnace 9. Specifically, the entire pressure-receiving portion 15a of the arm member 15 is located outside the forming furnace 9, while at least the portion of the pressing portion 15b of the arm member 15 corresponding to the point of action P2 is located within the forming furnace 9.

[0063] As a variation of this embodiment, a configuration may be employed in which a portion of the support brick 6 is extended outside the forming furnace 9 through the opening 9a of the forming furnace 9, and the pressing portion 15b of the arm member 15 presses the extended portion. In this case, the entire pressing portion 15b of the arm member 15 is located outside the forming furnace 9.

[0064] Hereinafter, the main functions and effects of the above-mentioned forming device 1 will be described.

[0065] In the aforementioned forming apparatus 1, the pressing device 8 is fixed to the forming furnace 9. Specifically, the pressing device 8 is fixed to the forming furnace 9 by fixing the holding member 17 of the pressing device 8 relative to the outer surface 10e of the frame 10. Therefore, when adjusting the position of the forming furnace 9, the pressing device 8, which includes the cylinder 14, the arm member 15, and the holding member 17, can be moved integrally with the forming furnace 9. Therefore, when adjusting the position of the formed body 4, etc., there is no need to change the position of the pressing device 8, making the operation easier. Furthermore, since there is no need for a mechanism to change the position of the pressing device 8, the equipment structure can be simplified.

[0066] Here, the following modifications can also be applied to the above-mentioned embodiment.

[0067] In the above embodiment, the rods 10d provided in the frame 10 are formed to extend parallel to the longitudinal direction of the molded body 4. However, as a modification, it is also possible to adopt Figure 3 In this embodiment, the two rods 10d extend along the diagonal lines of the rectangular shape of the frame 10 when viewed from the side. It should be noted that, as a further modification, one of the two rods 10d may be omitted.

[0068] In the lever mechanism 13 of the above embodiment, the cylinder 14 is fixed to the arm member 15, but the cylinder 14 may be fixed to the forming furnace 9. Also, the fulcrum P3 is positioned above the action point P2 and the effort point P1 is positioned above the fulcrum P3, but the fulcrum P3 may be positioned below the action point P2 and the effort point P1 may be positioned below the fulcrum P3.

[0069] In the pressing device 8 of the above-described embodiment, the actuator (cylinder 14), which is the force generating source, presses the support brick 6 via the lever mechanism 13. However, the actuator (force generating source) may press the support brick 6 via another mechanism, or the actuator may directly press the support brick 6. Furthermore, a counterweight may be used as the force generating source instead of the actuator. For example, the downward force generated by the weight of the counterweight may be converted into a lateral force using the lever mechanism 13 or the like to press the support brick 6.

[0070] In the pressing device 8 of the above-described embodiment, a single lever mechanism 13 is provided, but the pressing device 8 may be provided with two lever mechanisms. This will be described below.

[0071] like Figure 4 As shown, the lever mechanism 13 of the pressing device 8 is composed of a first lever mechanism 21 on the upper side and a second lever mechanism 22 on the lower side. The first lever mechanism 21 includes a first arm member 23 with a cylinder 14 and a pressure-receiving portion 15a (including a first force point P1a) provided at its upper end. Furthermore, the second lever mechanism 22 includes a second arm member 24 with a pressing portion 15b (including a second force point P2b) provided at its lower end via a shaft 16.

[0072] The first fulcrum P3a of the first lever mechanism 21 is formed by a shaft projection 25 fixed to the lower end of the first arm member 23 and disposed on the upper portion of the retaining member 17. The shaft projection 25 does not extend through the second arm member 24. Furthermore, the first point of action P2a of the first lever mechanism 21 is formed by a shaft 27 of a rod supported at the middle portion in the vertical direction of the first arm member 23 and inserted through a long hole 26 formed in the upper end of the second arm member 24.

[0073] The second fulcrum P3b of the second lever mechanism 22 is formed by the rod shaft 28 disposed at the bottom of the holding member 17, and supports the vertically intermediate portion of the second arm member 24. Furthermore, the second force point P1b of the second lever mechanism 22 is formed by the rod shaft 27 described above. Thus, the rod shaft 27 serves as both the first action point P2a of the first lever mechanism 21 and the second force point P1b of the second lever mechanism 22.

[0074] based on Figure 5 The detailed structure of the lever mechanism 13 will be described. As shown in the figure, the first arm member 23 of the first lever mechanism 21 includes two first arm plates 23a arranged in parallel at a first predetermined distance. A rod shaft 27, which serves as both the first point of action P2a and the second point of force P1b, is fixed across the two first arm plates 23a. Axial projections 25, which constitute the first fulcrum P3a, are projecting from the outer side surfaces 23aa of each of the two first arm plates 23a. These axial projections 25 are supported by shaft holes 29 formed in the upper portion of the retaining member 17.

[0075] The second arm member 24 of the second lever mechanism 22 includes two second arm plates 24a arranged in parallel at a second predetermined interval smaller than the first predetermined interval. A long hole 26 extending in the vertical direction is formed at the upper end of each of the two second arm plates 24a. The shaft 27 of the rod body is inserted through these long holes 26. The shaft 27 of the rod body is allowed to move relative to the longitudinal direction of the long holes 26, but is restricted from moving relative to the width direction perpendicular thereto. An axial hole 30 is formed in the middle portion of each of the two second arm plates 24a in the vertical direction. The shaft 28 of the rod body, which constitutes the second fulcrum P3b and is supported by the lower portion of the retaining member 17, is inserted into these axial holes 30.

[0076] The distance L1a from the first fulcrum P3a to the first force point P1a of the first lever mechanism 21 is, for example, 1.5 to 10 times the distance L2a from the first fulcrum P3a to the first point of application P2a. Meanwhile, the distance L1b from the second fulcrum P3b to the second force point P1b of the second lever mechanism 22 varies slightly with the rotational movement of the first arm member 23, but is, for example, 1.5 to 10 times the distance L2b from the second fulcrum P3b to the second point of application P2b.

[0077] Next, the effects of the forming apparatus 1 according to the fifth embodiment, having the above-described structure, will be described. When the air cylinder 14 operates, the piston rod, the output portion of the cylinder 14, presses against the outer surface 10e of the forming furnace 9. The resulting reaction force acts on the pressure-receiving portion 15a (first force point P1a of the first lever mechanism 21) at the upper end of the first arm member 23. The force applied to the pressure-receiving portion 15a is amplified by the first lever mechanism 21, resulting in a clockwise moment of force about the axial protrusion 25 (first fulcrum P3a of the first lever mechanism 21) acting on the rod shaft 27 (first force point P2a of the first lever mechanism 21).

[0078] At this time, the force generated at the rod shaft 27 (the second force point P1b of the second lever mechanism 22) is amplified by the second lever mechanism 22, so that a clockwise moment of force about the rod shaft 28 (the second fulcrum P3b of the second lever mechanism 22) acts on the pressing portion 15b (the second action point P2b of the second lever mechanism 22) provided at the lower end of the second arm member 24. This exerts a pressing force on the support brick 6.

[0079] In this embodiment, the force applied to the first force point P1a by the operation of the air cylinder 14 is amplified by 1.5 to 10 times by the first lever mechanism 21 and further amplified by 1.5 to 10 times by the second lever mechanism 22, thereby applying the force to the support brick 6 from the second action point P2b. Therefore, the forming device 1 of this fifth embodiment can apply a stronger pressing force to the support brick 6 than a case having a single lever mechanism.

[0080] Here, two lever mechanisms 21 and 22 are provided, but three or more lever mechanisms may be provided.

[0081] Description of Reference Numerals

[0082] 1 Glass forming device

[0083] 2 Molten Glass

[0084] 3 Glass ribbon

[0085] 4 formed body

[0086] 6 Support bricks

[0087] 7 Support bricks

[0088] 8 Pressing device

[0089] 9 Forming furnace

[0090] 10 Framework

[0091] 10a Main frame

[0092] 10b Main frame

[0093] 10d rod

[0094] 10e outer surface

[0095] 11 Refractory brick wall

[0096] 12 Heating device

[0097] 13 Lever mechanism

[0098] P1 force point

[0099] P2 action point

[0100] P3 fulcrum.

Claims

1. A glass forming device comprising: a forming body for forming a glass ribbon from molten glass using an overflow down-draw method; a support brick that supports the longitudinal end portion of the upper portion of the formed body from below and presses the lower portion of the formed body in the longitudinal direction; a pressing device that presses the supporting brick toward the formed body; and a forming furnace that accommodates the formed body therein, The glass forming device is characterized in that The pressing device is fixed to the forming furnace, The forming furnace includes a refractory brick wall surrounding the formed body, a heating device for heating the formed body from the side, and a frame surrounding the refractory brick wall and the heating device and fixing the pressing device.

2. The glass forming device according to claim 1, wherein The supporting bricks are arranged on both one end side and the other end side in the longitudinal direction of the formed body. The pressing device is configured to press only one of the two supporting bricks. The other of the two supporting bricks is held by the frame.

3. The glass forming device according to claim 1 or 2, characterized in that: The frame includes a pair of main frames disposed corresponding to both ends of the formed body in the longitudinal direction, and a rod spanned across the pair of main frames.

4. The glass forming device according to claim 3, wherein: The rods are arranged on both sides of the formed body with the formed body sandwiched therebetween.

5. The glass forming device according to claim 3, wherein: The rod extends parallel to the longitudinal direction of the formed body.

6. The glass forming device according to claim 5, characterized in that The pressing device has a lever mechanism configured to press the supporting brick using a force applied to a force point and then amplified to act on the force point. The rod is arranged at the same height as the fulcrum of the lever mechanism.

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