Glass forming equipment

Abstract

A glass molding apparatus 1 provided with a molded body 4 for molding a glass ribbon 3 from a molten glass 2 by an overflow downdraw method, supporting bricks 6, 7 for respectively supporting length-direction end parts of the molded body 4 from below in the upper part of the molded body 4 and for pressing the lower part of the molded body 4 in the length direction, a pressing device 8 for pressing the supporting brick 6 toward the molded body 4 side, and a molding furnace 9 in which the molded body 4 is accommodated therein, in which the pressing device 8 is fixed to the molding furnace 9.

Description

[Technical Field]

[0001] The present disclosure relates to glass forming devices. [Background technology]

[0002] As is well known, one of the techniques for producing a glass sheet is the overflow downdraw method. Patent Document 1 discloses an example of a production facility capable of carrying out the overflow downdraw method.

[0003] The manufacturing equipment disclosed in Patent Document 1 includes a wedge-shaped forming body that forms a glass ribbon (referred to as a sheet glass plate SG in the document) from molten glass, a pair of support bricks (referred to as a first support member 410 and a second support member 420 in the document) that support the forming body by sandwiching it from one end and the other end in the longitudinal direction, and a pressing device (referred to as a pressure device 422 in the document) that presses one of the pair of support bricks toward the forming body.

[0004] In the manufacturing equipment, compressive stress acts on the formed body in the longitudinal direction as the pressing device presses the support bricks, thereby suppressing creep deformation of the formed body due to its own weight, the weight of the molten glass, etc. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2012 / 132309 Summary of the Invention [Problem to be solved by the invention]

[0006] In the manufacturing facilities described above, there are cases where the positions of the compacts or the forming furnace that houses the compacts are moved before or during operation. In this case, if the pressing device is fixed to, for example, a building, the position of the pressing device needs to be changed according to the movement of the compacts, etc. This makes the work of adjusting the positions of the compacts, etc. cumbersome. In addition, a mechanism for changing the position of the pressing device is required, which makes the facility configuration cumbersome.

[0007] In view of the above circumstances, a technical problem to be solved is to provide a manufacturing facility that can easily adjust the position of a compact, etc., while suppressing creep deformation of the compact. [Means for solving the problem]

[0008] A glass forming apparatus for solving the above problems includes a forming body that forms a glass ribbon from molten glass by the overflow downdraw method, support bricks that support the longitudinal ends of the forming body at the top of the forming body from below and press the lower part of the forming body in the longitudinal direction, a pressing device that presses the support bricks toward the forming body, and a forming furnace that houses the forming body inside, and is characterized in that the pressing device is fixed to the forming furnace.

[0009] In this glass forming apparatus, the pressing device is fixed to the forming furnace, so it moves along with the forming furnace. This eliminates the need to change the position of the pressing device when adjusting the position of a formed body, making the work easier. In addition, the absence of a mechanism for changing the position of the pressing device simplifies the equipment configuration.

[0010] In the above configuration, it is preferable that the forming furnace has a firebrick wall surrounding the formed body, a heating device that heats the formed body from the side, and a frame that surrounds the firebrick wall and the heating device and to which the pressing device is fixed.

[0011] In this way, when the pressing device presses the support bricks toward the molded body to suppress creep deformation of the molded body, the reaction force can be absorbed by the frame. Furthermore, since the frame surrounds both the firebrick wall and the heating device and is positioned outside both, it is possible to avoid the frame being damaged by heat.

[0012] In the above configuration, it is preferable that the support bricks are arranged at both one end and the other end of the longitudinal direction of the molded body, the pressing device is configured to press only one of the two support bricks, and the other of the two support bricks is held in the frame.

[0013] In this way, the pressing device presses only one of the two support bricks, further simplifying the structure of the equipment. Also, since the other support brick is held by the frame, the reaction force can be absorbed by the frame.

[0014] In the above configuration, it is preferable that the frame includes a pair of main frames arranged corresponding to both longitudinal ends of the molded body, and a bar spanning the pair of main frames.

[0015] In this way, the reaction force can be suitably absorbed by the bar. Furthermore, by providing the bar on the frame, it is possible to eliminate as much as possible the risk of the frame undergoing plastic deformation when absorbing the reaction force.

[0016] In the above configuration, it is preferable that the bars are arranged on both sides of the molded body with the molded body sandwiched therebetween.

[0017] In this way, the bars arranged on both sides of the molded body (on one side and the other side of the molded body) can absorb the reaction force in a balanced manner.

[0018] In the above configuration, it is preferable that the bar extends parallel to the longitudinal direction of the molded body.

[0019] In this way, the direction of the pressing force applied when the pressing device presses the support brick is the same as the direction in which the bar extends, so the reaction force can be efficiently absorbed by the frame.

[0020] In the above configuration, the pressing device preferably has a lever mechanism configured to press the support brick by utilizing a force that is applied to the force point and then amplified and acts on the action point, and the bar is preferably positioned at the same height as the fulcrum of the lever mechanism.

[0021] In this way, the pressing device has a lever mechanism, and the pressing device presses the support bricks using the force acting on the point of application of the lever mechanism, which is advantageous in pressing the support bricks with a large force. In addition, since the bar is positioned at the same height as the fulcrum of the lever mechanism, it is possible to efficiently absorb the force in the direction of separation. [Effects of the Invention]

[0022] According to the glass forming apparatus of the present disclosure, it is possible to easily adjust the position of the formed body while suppressing creep deformation of the formed body. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 2 is a side view showing the glass forming device. [Figure 2] FIG. 2 is a cross-sectional view showing the cross section AA in FIG. [Figure 3] FIG. 10 is a side view showing a modified example of the glass forming device. [Figure 4] FIG. 10 is a side view showing another modified example of the glass forming device. [Figure 5] FIG. 10 is an exploded view showing a partial configuration of another modified example of the glass forming device. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, a glass forming apparatus according to an embodiment will be described with reference to the accompanying drawings. Note that the X, Y, and Z directions shown in each drawing referred to in the description of the embodiment are directions that are perpendicular to one another.

[0025] As shown in Figures 1 and 2, the glass forming apparatus 1 (hereinafter simply referred to as the forming apparatus 1) includes a forming body 4 that forms a glass ribbon 3 from molten glass 2, a supply pipe 5 that supplies the molten glass 2 to the forming body 4, a pair of support bricks 6, 7 that support the forming body 4, a pressing device 8 that presses the support brick 6 of the two support bricks 6, 7 toward the forming body 4, and a forming furnace 9 that accommodates the forming body 4 inside.

[0026] The formed body 4 and both support bricks 6 and 7 are placed inside the forming furnace 9. The forming furnace 9 includes a frame 10, a refractory brick wall 11 (shown only in FIG. 2) that is placed inside the enclosure of the frame 10 and surrounds the formed body 4, and a heating device 12 (shown only in FIG. 2) that is placed between the frame 10 and the refractory brick wall 11.

[0027] The frame 10 has a rectangular box-like outer shape that is elongated in the X direction and also functions as a casing. The frame 10 includes a pair of main frames 10a, 10b disposed at both longitudinal ends of the compact 4, and a beam 10c and a bar 10d that span the two main frames 10a, 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 that makes up the frame 10 is preferably 80 GPa or more, and more preferably 150 GPa or more.

[0028] Each of the main frames 10a, 10b has a framework made up of plates and rods extending in the X, Y, and Z directions. The lower parts of the main frames 10a, 10b support supporting bricks 6, 7, respectively. The beams 10c and bars 10d extend parallel to the longitudinal direction of the molded body 4.

[0029] At least four beams 10c are provided, and these four beams correspond to the four sides of the rectangular parallelepiped that is the external shape of the frame 10, extending in the X direction.

[0030] The bars 10d are arranged on both sides of the formed body 4, sandwiching the formed body 4 therebetween. That is, a pair of the bars 10d are arranged with a gap in the Y direction. Each of the pair of bars 10d, 10d is arranged at a height between the upper and lower beams 10c of the four beams 10c. The height at which the pair of bars 10d, 10d are arranged is the same height as the fulcrum P3 of the lever mechanism 13, which will be described later. Note that, as in this embodiment, when the fulcrum P3 is located at a height between the upper and lower ends of the frame 10 (here, the height between the upper beam 10c and the lower beam 10c), the bar 10d can effectively perform its function by aligning the heights of the bar 10d and the fulcrum P3 (details will be described later). Each of the pair of bars 10d, 10d is fixed to the side of each of the main frames 10a, 10b. That is, the main frames 10a and 10b are sandwiched between the pair of bars 10d and 10d. The cross-sectional shape of the bar 10d (the shape of a cross section perpendicular to the X direction) may be any shape, for example, rectangular or circular.

[0031] As a modification of this embodiment, the number of bars 10d is not limited to one, and multiple pairs may be provided on the frame 10. That is, in addition to a pair of bars 10d, 10d arranged at the same height as the fulcrum P3 of the lever mechanism 13, the frame 10 may be provided with one or multiple pairs of bars 10d, 10d arranged at a different height from the fulcrum P3. Furthermore, each bar 10d does not necessarily have to be fixed to the sides of both main frames 10a, 10b. For example, each bar 10d may be fixed in a state where it is interposed between both main frames 10a, 10b. In this case, one end of each bar 10d is connected to the main frame 10a, and the other end is connected to the main frame 10b.

[0032] The firebrick wall 11 is made up of a plurality of firebricks and is formed in the shape of a room that covers the molded body 4 from above and from the sides. The firebrick wall 11 includes a pair of plate-shaped firebricks 11a, 11a that are spaced apart in the Y direction. The pair of plate-shaped firebricks 11a, 11a are arranged on both sides of the molded body 4, with the molded body 4 sandwiched between them. Each plate-shaped firebrick 11a is in contact with both support bricks 6, 7 from the sides. The firebrick wall 11 is held by the frame 10 via heat insulating members (e.g., firebricks) not shown.

[0033] The heating device 12 can heat the molded body 4 from the side via the plate-shaped firebrick 11a. The heating devices 12 are arranged on both sides of the molded body 4 with the molded body 4 sandwiched therebetween. Furthermore, a plurality of heating devices 12 are arranged along the longitudinal direction of the molded body 4 on both sides of the molded body 4. Each of the plurality of heating devices 12 is attached to a beam (not shown) (separate from the above-mentioned four beams 10c) provided on the frame 10 and is in contact with the plate-shaped firebrick 11a. In this embodiment, a panel heater is used as the heating device 12. Of course, this is not limited to this, and as a modification of this embodiment, something other than a panel heater may be used as the heating device 12.

[0034] 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 at the opening 9a.

[0035] The molded body 4 is a molded body for an overflow downdraw process having a wedge-shaped cross section (a cross section perpendicular to the X direction). The molded body 4 is made of dense zircon, alumina-based, zirconia-based or other refractory bricks.

[0036] Molten glass 2 is poured into grooves (not shown) formed in the upper part of forming body 4, and then the molten glass 2 overflowing on both sides from the grooves is caused to flow down along a pair of side surfaces 4b, 4b (only one of the pair is shown in FIG. 1) of forming body 4. Thereafter, the molten glass 2 that has flowed down both side surfaces 4b, 4b joins at a lower end 4c of forming body 4. A glass ribbon 3 is formed from the molten glass 2 that joins at the lower end 4c.

[0037] The dimension along the longitudinal direction of the molded body 4 is, for example, 1500 mm to 6000 mm. Since the above-mentioned frame 10 is effective when a large molded body 4 is provided, a preferable lower limit of the dimension along the longitudinal direction of the molded body 4 is 2000 mm or more, 2500 mm or more, 3000 mm or more, 3500 mm or more, particularly 4000 mm or more.

[0038] The supply pipe 5 supplies the molten glass 2 to the forming body 4 from one end in the longitudinal direction thereof.

[0039] Each of the pair of support bricks 6, 7 presses the molded body 4 in the longitudinal direction while supporting the longitudinal ends of the molded body 4 from below. Specifically, both longitudinal ends of the upper part of the molded body 4 are placed on the upper surfaces of the pair of support bricks 6, 7, thereby supporting the molded body 4 in a spanning state. Each of the pair of support bricks 6, 7 has a pressing surface S for pressing the molded body 4, and presses the molded body 4 in the longitudinal direction with this pressing surface S in surface contact with the longitudinal end face 4d of the lower part of the molded body 4. Note that the pressing surfaces S of both support bricks 6, 7 and the end face 4d of the molded body 4 are both vertical flat surfaces, but may also be inclined surfaces or include curved surfaces. Of the two support bricks 6, 7, the support brick 7 is held so that it cannot move along the longitudinal direction of the molded body 4. On the other hand, the support brick 6 can be moved toward the molded body 4 as it is pressed by the pressing device 8. In this embodiment, the support brick 7 is fixed to a frame 10, and the support brick 6 is held by the frame 10 so as to be movable along the longitudinal direction of the molded body 4.

[0040] The pressing device 8 is disposed on the opposite side of the supply pipe 5 in the longitudinal direction of the molded body 4. Of the pair of support bricks 6, 7, the pressing device 8 presses only the support brick 6. As the pressing device 8 presses the support brick 6, it applies a compressive stress in the longitudinal direction to the molded body 4 sandwiched between the support bricks 6, 7. This suppresses creep deformation of the molded body 4 due to its own weight, etc.

[0041] The pressing device 8 has a lever mechanism 13 that amplifies the force applied to the force point P1 and applies it to the action point P2, and an air cylinder 14 that serves as an actuator that generates the force applied to the force point P1. The pressing device 8 presses the support brick 6 using the force that acts on the action point P2.

[0042] 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, or the like may be used instead of the air cylinder 14. Furthermore, a weight may be used as a force generating source instead of an actuator.

[0043] The lever mechanism 13 includes an arm member 15 having a pressure receiving portion 15a and a pressing portion 15b, and a holding member 17 that holds the arm member 15 in a state that allows the arm member 15 to swing around a fulcrum P3.

[0044] The arm member 15 is a member that is elongated in one direction, extending vertically. The pressure-receiving portion 15a located on the upper end side of the arm member 15 is a portion that receives a force generated by the air cylinder 14 as a source, and is a portion that corresponds to the point of force P1. On the other hand, the pressing portion 15b located on the lower end side of the arm member 15 is a portion that presses the support brick 6, and is a portion that corresponds to the point of action P2. The distance L1 from the fulcrum P3 to the point of force P1 is longer than the distance L2 from the fulcrum P3 to the point of action P2. It is preferable that the distance L1 is 1.2 to 3.0 times the distance L2.

[0045] The pressing portion 15b of the arm member 15 is formed of a disk that is rotatable around a shaft 16. That is, the pressing portion 15b is rotatably held by the shaft 16 at the lower end of the arm member 15. The shaft 16 extends parallel to a rod 17a (described below) provided on the holding member 17.

[0046] The holding member 17 is fixed to the outer surface 10e of the frame 10. In other words, the lever mechanism 13 is fixed to the outer surface 10e of the frame 10 via the holding member 17. The holding member 17 has a rod 17a that extends in the Y direction and passes through the arm member 15, and the rod 17a serves as the central axis of swing of the arm member 15 and as a fulcrum P3 of the lever mechanism 13.

[0047] The air cylinder 14 has one end (the end opposite to the tip of the piston rod) fixed to the pressure-receiving portion 15a of the arm member 15. The air cylinder 14 is disposed above the rod body 17a (fulcrum P3) provided on the holding member 17, between the pressure-receiving portion 15a of the arm member 15 and the outer surface 10e of the frame 10.

[0048] 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 tip (the part that directly contacts the outer surface 10e of the frame 10) is formed into a convex curved surface.

[0049] The center of gravity of the air cylinder 14 is located in the X direction on the opposite side of the rod 17a (fulcrum P3) from the outer surface 10e of the frame 10. As a result, the air cylinder 14 generates a clockwise force moment (clockwise in FIG. 1) around the rod 17a due to its own weight.

[0050] When the air cylinder 14 operates, its output part, a piston rod, presses against the outer surface 10e of the frame 10. The reaction force generated at this time is utilized to apply a force to the pressure-receiving part 15a of the arm member 15. The force received by the pressure-receiving part 15a is then amplified by the lever mechanism 13 and becomes a force that presses against the support brick 6. In addition, the moment of the force due to the weight of the air cylinder 14 described above is utilized to further press against the support brick 6.

[0051] The height at which the pair of bars 10d, 10d are arranged does not necessarily have to be the same as the height of the fulcrum P3 of the lever mechanism 13, and there may be a difference therebetween. From the viewpoint of efficiently absorbing the reaction force, the difference between the height at which the pair of bars 10d, 10d and the height of the fulcrum P3 of the lever mechanism 13 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.

[0052] As described above, the height at which the pair of bars 10d, 10d are arranged is the same as the fulcrum P3 of the lever mechanism 13. As a result, the bar 10d provides the following effect when the pressing device 8 presses the support brick 6. When the pressing device 8 presses the support brick 6, a force (reaction force) acting in a direction away from the molded body 4 acts on the part of the frame 10 at the height where the fulcrum P3 is located. However, this force can be efficiently absorbed by the bar 10d, which is arranged at the same height as the fulcrum P3.

[0053] The holding member 17 and the air cylinder 14 provided in the lever mechanism 13 are disposed outside the forming furnace 9. On the other hand, the arm member 15 provided in the lever mechanism 13 is disposed so as to straddle the inside and outside of the forming furnace 9 through an opening 9a of the forming furnace 9. In detail, the entire pressure-receiving portion 15a of the arm member 15 is located outside the forming furnace 9, whereas at least the portion of the pressing portion 15b of the arm member 15 corresponding to the action point P2 is inserted into the forming furnace 9.

[0054] Here, as a modified example of this embodiment, a configuration may be adopted in which a part of the support brick 6 protrudes outside the forming furnace 9 through the opening 9a of the forming furnace 9, and the protruding part is pressed by the pressing portion 15b of the arm member 15. In this case, the entire pressing portion 15b of the arm member 15 is present outside the forming furnace 9.

[0055] The main actions and effects of the molding device 1 will be described below.

[0056] In the above-described molding apparatus 1, the pressing device 8 is fixed to the molding furnace 9. Specifically, the holding member 17 of the pressing device 8 is fixed to the outer surface 10e of the frame 10, thereby fixing the pressing device 8 to the molding furnace 9. Therefore, when adjusting the position of the molding furnace 9, the pressing device 8, which includes the air cylinder 14, the arm member 15, and the holding member 17, can be moved integrally with the molding furnace 9. Therefore, when adjusting the position of the compact 4, etc., it is not necessary to change the position of the pressing device 8, which makes the work easier. Furthermore, a mechanism for changing the position of the pressing device 8 is not required, which simplifies the equipment configuration.

[0057] Here, the following modifications can also be applied to the above embodiment.

[0058] In the above embodiment, the bar 10d provided on the frame 10 extends parallel to the longitudinal direction of the molded body 4, but as a modification, a configuration as shown in Fig. 3 may be adopted. In this configuration, the two bars 10d extend along the diagonals of the rectangle formed by the frame 10 in a side view. Note that, as a further modification, one of the two bars 10d may be omitted.

[0059] In the lever mechanism 13 of the above embodiment, the air cylinder 14 is fixed to the arm member 15, but the air cylinder 14 may be fixed to the forming furnace 9. Furthermore, the fulcrum P3 is located above the point of action P2 and the point of force P1 is located above the fulcrum P3, but the fulcrum P3 may be located below the point of action P2 and the point of force P1 may be located below the fulcrum P3.

[0060] In the pressing device 8 of the above embodiment, the actuator (air cylinder 14) which is the force generating source presses the support brick 6 via the lever mechanism 13, but the actuator (force generating source) may press the support brick 6 via another mechanism, or the actuator may directly press the support brick 6. Also, instead of the actuator, a weight may be used as the force generating source, and for example, the downward force due to the weight of the weight may be converted into a horizontal force by the lever mechanism 13 or the like to press the support brick 6.

[0061] Although the pressing device 8 of the above embodiment is configured to include one lever mechanism 13, it may also be configured to include two lever mechanisms. This will be described below.

[0062] 4, the lever mechanism 13 of the pressing device 8 is made up of an upper first lever mechanism 21 and a lower second lever mechanism 22. The first lever mechanism 21 has a first arm member 23 having an air cylinder 14 and a pressure receiving portion 15a (including a first force point P1a) at its upper end. The second lever mechanism 22 has a second arm member 24 having a pressing portion 15b (including a second application point P2b) at its lower end via a shaft 16.

[0063] First fulcrum P3a of first lever mechanism 21 is formed by a shaft protrusion 25 fixed to the lower end of first arm member 23, and is disposed on the upper part of holding member 17. This shaft protrusion 25 does not pass through second arm member 24. In addition, first point of action P2a of first lever mechanism 21 is formed by a rod-shaped shaft 27 supported at the vertical middle part of first arm member 23, and is inserted into elongated hole 26 formed in the upper end of second arm member 24.

[0064] The second fulcrum P3b of the second lever mechanism 22 is formed by the shaft 28 of a rod body disposed at the bottom of the holding member 17, and supports a vertically intermediate portion of the second arm member 24. The second force point P1b of the second lever mechanism 22 is formed by the shaft 27 of the rod body described above. Therefore, this rod body shaft 27 is configured to serve as both the first point of action P2a of the first lever mechanism 21 and the second force point P1b of the second lever mechanism 22.

[0065] The detailed configuration of this lever mechanism 13 will be described with reference to FIG. 5. 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 with a first predetermined distance between them. A rod-shaped shaft 27, which also serves as the first point of application P2a and the second point of force P1b, is fixed across the two first arm plates 23a. A shaft protrusion 25 forming the first fulcrum P3a protrudes from each of the outer surfaces 23aa of the two first arm plates 23a. Each of these shaft protrusions 25 is supported in a shaft hole 29 formed in the upper portion of the holding member 17.

[0066] 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 that is smaller than the first predetermined interval. A vertically long slot 26 is formed in each of the upper ends of the two second arm plates 24a. A shaft 27 of the rod body described above is inserted into each of the slots 26. The rod shaft 27 is permitted to move relative to the longitudinal direction of the slots 26, but is restricted from moving relative to the longitudinal direction in the width direction perpendicular to the longitudinal direction. A shaft hole 30 is formed in each of the two second arm plates 24a in the vertical middle. A shaft 28 of a rod body that constitutes a second fulcrum P3b supported by the lower part of the holding member 17 fits into each of the shaft holes 30.

[0067] The distance L1a from the first fulcrum P3a to the first point of force P1a in 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 point of application P1b in 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.

[0068] Next, the effects of the molding apparatus 1 according to the fifth embodiment having the above-described configuration will be described. When the air cylinder 14 is operated, the piston rod, which is its output portion, presses against the outer surface 10e of the molding furnace 9. The reaction force generated at this time is utilized to apply a force to the pressure-receiving portion 15a (first force point P1a of the first lever mechanism 21) provided at the upper end of the first arm member 23. The force received by the pressure-receiving portion 15a is then amplified by the first lever mechanism 21, and a clockwise force moment acts on the shaft 27 of the rod body (first force point P2a of the first lever mechanism 21) around the shaft protrusion 25 (first fulcrum P3a of the first lever mechanism 21).

[0069] At this time, the force generated at the rod axis 27 (second point of force P1b of the second lever mechanism 22) is amplified by the second lever mechanism 22, and a clockwise force moment acts around the rod axis 28 (second fulcrum P3b of the second lever mechanism 22) on the pressing part 15b (second point of application P2b of the second lever mechanism 22) provided at the lower end of the second arm member 24. As a result, a pressing force is applied to the support brick 6.

[0070] In this embodiment, the force acting on 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, and is applied from the second application point P2b to the support brick 6. Therefore, according to the molding device 1 of this fifth embodiment, it is possible to apply a stronger pressing force to the support brick 6 than in the case where a single lever mechanism is provided.

[0071] Here, two lever mechanisms 21 and 22 are provided, but three or more lever mechanisms may be provided. [Explanation of symbols]

[0072] 1. Glass forming equipment 2 Molten Glass 3. Glass Ribbon 4 Molded body 6 Support bricks 7 Support bricks 8 Pressing device 9 Molding furnace 10 frames 10a Mainframe 10b Mainframe 10d bar 10e Exterior 11 Firebrick wall 12 Heating device 13 Leverage mechanism P1 emphasis P2 Point of action P3 fulcrum

Claims

1. a forming body for forming a glass ribbon from molten glass by an overflow downdraw method; a support brick that supports an end portion of the molded body in the longitudinal direction at an upper portion of the molded body from below and presses a lower portion of the molded body in the longitudinal direction; a pressing device that presses the support brick toward the molded body; a forming furnace that accommodates the formed body therein, the pressing device is fixed to the forming furnace, The glass forming apparatus is characterized in that the forming furnace has a firebrick wall surrounding the forming body, a heating device that heats the forming body from the side, and a frame that surrounds the firebrick wall and the heating device and to which the pressing device is fixed.

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

3. The glass forming apparatus according to claim 1 or 2, characterized in that the frame comprises a pair of main frames arranged corresponding to both ends of the forming body in the longitudinal direction, and a bar spanning the pair of main frames.

4. 4. The glass forming apparatus according to claim 3, wherein the bars are disposed on both sides of the forming body with the forming body sandwiched therebetween.

5. 5. The glass forming apparatus according to claim 3, wherein the bar extends parallel to the longitudinal direction of the forming body.

6. The pressing device has a lever mechanism configured to press the support brick by utilizing a force that is applied to a force point, is amplified, and acts on a force point, 6. The glass forming apparatus according to claim 5, wherein the bar is disposed at the same height as a fulcrum of the lever mechanism.

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