Glass article manufacturing apparatus and glass article manufacturing method

Abstract

To appropriately arrange a rib part to a tubular part of a transfer tube, when the tubular part has a seam part and also the rib part has a seam part, to suppress the damage of the tubular part due to thermal expansion caused by electric heating in the peripheral direction.SOLUTION: An apparatus 1 for manufacturing a glass article includes a transfer tube P1 for transferring molten glass Gm. The transfer tube P1 includes a tubular part 14 having molten glass Gm flowing into the inside and electric heating electrode parts 15a and 16a attached on the outer peripheral side of the tubular part 14; the tubular part 14 includes a seam part 14a extended in the tube axis Z direction; an annular rib part 24 is attached to the tubular part 14; the rib part 24 includes a seam part 24a in the middle in the peripheral direction of the tubular part 14; and a position of the seam part 14a of the tubular part 14 is different from that of the seam part 24a of the rib part 24 in the peripheral direction of the tubular part 14.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a manufacturing apparatus for glass articles and a manufacturing method for glass articles, which include a transfer pipe for transferring molten glass.

Background Art

[0002] As is well known, when manufacturing glass articles such as glass plates and glass tubes, molten glass is transferred from a melting furnace to a forming apparatus. A plurality of transfer pipes are arranged in the path for transferring this molten glass.

[0003] Main transfer pipes include, in order from the upstream side of the transfer path, those constituting a fining tank, a stirring tank, a cooling pipe, etc. respectively. There are also transfer pipes that constitute an upstream connection pipe interposed between the melting furnace and the fining tank, a midstream connection pipe interposed between the fining tank and the stirring tank, etc. respectively.

[0004] Patent Document 1 discloses joining both circumferential ends of a pipe material that constitutes a tubular portion through which molten glass flows inside a transfer pipe (the transfer pipe constituting a stirring tank in the same document) by welding. Therefore, a joint portion (joining portion) extending in the pipe axis direction is provided in the tubular portion of the same document.

[0005] Patent Document 2 discloses attaching an electrode portion for electric heating to the outer peripheral side of a tubular portion in a transfer pipe. In the same document, the electrode portion is integrally attached to the outer peripheral side of a flange portion provided at the pipe axis direction end of the tubular portion.

[0006] Patent Document 3 discloses attaching a flange-shaped reinforcing member (annular rib portion) to the outer peripheral side of a tubular portion in a transfer pipe. In the same document, the annular rib portion is attached by plasma welding at a plurality of locations in the pipe axis direction of the tubular portion.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0008] By the way, when an electrode part as disclosed in Patent Document 2 is attached to a tubular part having a joint part as disclosed in Patent Document 1 and the molten glass flowing inside the tubular part is heated by energization, thermal stress is generated in the tubular part during the temperature rise process, making the tubular part prone to deformation and possibly leading to damage. With the configuration disclosed in Patent Document 3, the deformation of the tubular part can be suppressed by the annular rib part, but there are still problems to be solved as described below.

[0009] That is, as a method of attaching an annular rib part to the outer peripheral side of the tubular part, the present inventor tried to join both ends of the rib material constituting the rib part by welding or the like in a state where the rib material is arranged along the circumferential direction on the outer peripheral surface of the tubular part. In such a case, a joint part (seam part) is provided in the middle of the circumferential direction of the rib part. Under this configuration, in order to avoid damage such as cracks that may occur in the tubular part (its joint part) due to thermal stress, the problem becomes how to arrange the rib part with respect to the tubular part.

[0010] From the above viewpoints, the problem of the present invention is to appropriately arrange the rib part with respect to the tubular part when the tubular part of the transfer pipe has a joint part and the rib part also has a joint part, and suppress damage to the tubular part caused by circumferential thermal stress caused by energization heating.

Means for Solving the Problems

[0011] A first aspect of the present invention devised to solve the above problems is a manufacturing apparatus for glass articles including a transfer pipe for transferring molten glass, the transfer pipe including a tubular portion through which the molten glass flows inside, and an electrode portion attached to the outer peripheral side of the tubular portion and passing an electric current through the tubular portion, the tubular portion having a joint portion extending along the tube axis direction, an annular rib portion being attached to the tubular portion, the rib portion having a joint portion in the middle of the circumferential direction of the tubular portion, and the position of the joint portion of the tubular portion and the position of the joint portion of the rib portion being different in the circumferential direction of the tubular portion.

[0012] According to such a configuration, even if thermal stress is generated in the tubular portion by energization heating by the electrode portion, since the positions of the joint portion of the tubular portion and the joint portion of the rib portion are different in the circumferential direction, a situation where damage such as a crack occurs in the tubular portion can be suppressed. More specifically, since the joint portion of the tubular portion is a joint portion by welding or the like, its strength is low. Also, since the joint portion of the rib portion is also a joint portion by welding or the like, its strength is low. Therefore, when the positions of these two joint portions overlap in the circumferential direction, the two portions with insufficient strength against thermal expansion overlap in the circumferential direction, which becomes a factor for causing damage such as a crack in the tubular portion (its joint portion). In the configuration here, since the positions of the two joint portions are different in the circumferential direction, such a problem is less likely to occur, and the strength of the tubular portion and thus the transfer pipe can be improved.

[0013] In this configuration, the tubular portion may be formed of platinum or a platinum alloy, and the rib portion may be formed of reinforced platinum or a reinforced platinum alloy.

[0014] By doing so, since the tubular portion has lower brittleness than the rib portion, the thermal stress generated in the tubular portion by energization heating can be reduced, and damage to the tubular portion can be efficiently suppressed. Moreover, since the rib portion has higher strength than the tubular portion, the effect of reducing the deformation of the tubular portion by the rib portion is improved. Also, compared with the case where both the rib portion and the tubular portion are formed of reinforced platinum or a reinforced platinum alloy for improving strength against thermal expansion, the manufacturing cost can be suppressed, and the strength of the tubular portion and thus the transfer pipe can be improved efficiently.

[0015] In the above configuration, the transfer pipe may form a stirring tank in which the axial direction of the tubular portion is along the vertical direction, and an inflow pipe and an outflow pipe may be respectively connected to the inflow port and the outflow port of the molten glass provided in the tubular portion from the outside.

[0016] In this way, even if the inflow pipe and the outflow pipe each undergo thermal expansion in the pipe axial direction, the adverse effects associated therewith can be suppressed. More specifically, when both pipes undergo thermal expansion in the pipe axial direction, the stirring tank is pushed by both pipes, and thus the cross-sectional shape in plan view is likely to deform from a circle to an ellipse and be damaged. In the present invention, as described above, since the positions of the joint portions of both the tubular portion and the rib portion are different in the circumferential direction, such deformation and damage can be appropriately dealt with.

[0017] In this case, the position of the joint portion of the tubular portion and the positions of the inflow port and the outflow port may be different in the circumferential direction of the tubular portion.

[0018] In this way, even if the stirring tank is pushed by both pipes due to the above-described thermal expansion of both pipes in the pipe axial direction, it is difficult for the pressing force to act on the joint portion of the tubular portion, so that damage to the tubular portion (its joint portion) and thus the stirring tank can be efficiently avoided.

[0019] Also, the position of the joint portion of the rib portion and the positions of the inflow port and the outflow port may be different in the circumferential direction of the tubular portion.

[0020] In this way, even if the stirring tank is pushed by both pipes due to the above-described thermal expansion of both pipes in the pipe axial direction, it is difficult for the pressing force to act on the joint portion of the rib portion, so that damage to the rib portion (its joint portion) and thus the stirring tank can be efficiently avoided.

[0021] In these configurations, the position of the inlet and the position of the outlet may face each other across the tube axis of the tubular portion in a plan view, and the position of the joint portion of the tubular portion and the position of the joint portion of the rib portion may face each other across the virtual straight-line path from the inlet to the outlet in a plan view.

[0022] In this way, even when the stirring tank is pushed by the above-described two pipes due to thermal expansion, both joint portions of the tubular portion and the rib portion are located at positions sufficiently separated from the position where the pressing force acts, so that damage to the stirring tank can be more reliably avoided.

[0023] A second aspect of the present invention devised to solve the above problems is a method for manufacturing a glass article, characterized by including a step of transferring molten glass using a transfer pipe provided in the above-described manufacturing apparatus.

[0024] According to this method, it is possible to enjoy substantially the same operational effects as those of the manufacturing apparatus for glass articles according to the present invention already described.

Effects of the Invention

[0025] According to the present invention, when the tubular portion of the transfer pipe has a joint portion and the rib portion also has a joint portion, the rib portion is appropriately arranged with respect to the tubular portion, so that damage to the tubular portion due to circumferential thermal expansion caused by energization heating is suppressed.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0027] Hereinafter, a glass article manufacturing apparatus and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0028] FIG. 1 illustrates a glass article manufacturing apparatus according to the present invention. As shown in the figure, this manufacturing apparatus 1 is roughly divided into a melting furnace 2 provided at the upstream end for heating a glass raw material to generate molten glass Gm, a transfer device 3 for transferring the molten glass Gm flowing out from the melting furnace 2 toward the downstream side, and a forming device 4 for forming a glass ribbon Gr using the molten glass Gm supplied from the transfer device 3.

[0029] The transfer device 3 includes, in order from the upstream side, a clarification tank 5, a stirring tank 6, and a state adjustment tank 7. The inflow portion 5a of the clarification tank 5 communicates with the outflow portion 2b of the melting furnace 2 via an upstream connection pipe 8. The outflow portion 5b of the clarification tank 5 communicates with the inflow portion 6a of the stirring tank 6 via a middle connection pipe 9. The outflow portion 6b of the stirring tank 6 communicates with the inflow portion 7a of the state adjustment tank 7 via a cooling pipe 10.

[0030] The fining tank 5 subjects the molten glass Gm produced in the melting furnace 2 to a fining process. The stirring tank 6 stirs the molten glass Gm that has undergone the fining process to perform a homogenization process. The cooling pipe 10 cools the molten glass Gm that has undergone the homogenization process to adjust its viscosity and the like. The state adjustment tank 7 further adjusts the viscosity, flow rate, and the like of the cooled molten glass Gm. Note that a plurality of stirring tanks 6 may be arranged in the transfer path of the transfer device 3.

[0031] The forming device 4 includes a formed body 11 that causes the molten glass Gm to flow down by the overflow down-draw method to form a strip shape, and a large-diameter introduction pipe 12 that guides the molten glass Gm to the formed body 11. The molten glass Gm is supplied to the introduction pipe 12 from the state adjustment tank 7 of the transfer device 3 via a small-diameter pipe 13.

[0032] The glass ribbon Gr formed in a strip shape is supplied to a slow cooling process and a cutting process, and plate glass of a desired size is cut out as a glass article. The plate glass obtained here has, for example, a thickness of 0.01 to 2 mm and is used for glass substrates and cover glasses of displays such as liquid crystal displays and organic EL displays. Note that the forming device 4 may execute another down-draw method such as the slot down-draw method, or may execute a method other than the down-draw method, for example, the float method.

[0033] As the glass of the plate glass, silicate glass and silica glass are used. Preferably, borosilicate glass, soda-lime glass, aluminosilicate glass, and chemically strengthened glass are used. Most preferably, non-alkali glass is used. Here, non-alkali glass means glass that substantially does not contain an alkali component (alkali metal oxide), and specifically, glass having a weight ratio of the alkali component of 3000 ppm or less. In the present invention, the weight ratio of the alkali component is preferably 1000 ppm or less, more preferably 500 ppm or less, and most preferably 300 ppm or less.

[0034] The clarification tank 5, stirring tank 6, state adjustment tank 7, upstream connection pipe 8, middle stream connection pipe 9, and cooling pipe 10 of the transfer device 3 are all composed of transfer pipes. It should be noted that the clarification tank 5, stirring tank 6, state adjustment tank 7, upstream connection pipe 8, middle stream connection pipe 9, and cooling pipe 10 may each be composed of connecting a plurality of transfer pipes. Hereinafter, these transfer pipes will be described in detail.

[0035] Figures 2 to 4 illustrate the transfer pipe P1 (hereinafter referred to as the first transfer pipe P1) according to the first example. In the present embodiment, the first transfer pipe P1 constitutes the stirring tank 6. FIG. 2 is a perspective view showing the first transfer pipe P1, FIG. 3 is a longitudinal side view cut along the line A-A of FIG. 2, and FIG. 4 is a cross-sectional plan view cut along the line B-B of FIG. 2. As shown in each of these figures, the first transfer pipe P1 includes a tubular portion 14 whose pipe axis Z extends along the vertical direction (preferably the vertical direction). An upper flange portion 15 and a lower flange portion 16 are respectively attached to the upper end and the lower end of the tubular portion 14. The upper flange portion 15 has an opening corresponding to the inner peripheral surface of the tubular portion 14, while the lower flange portion 16 is in the form of a blind flange having no such opening. An upper electrode portion 15a is integrally attached to the outer peripheral side of the upper flange portion 15, and a lower electrode portion 16a is integrally attached to the outer peripheral side of the lower flange portion 16. An inlet 17 and an outlet 18 for the molten glass Gm are respectively formed in the upper and lower portions of the peripheral wall of the tubular portion 14. An inlet pipe 19 constituting the inflow portion 6a (see FIG. 1) is connected to the inlet 17, and an outlet pipe 20 constituting the outflow portion 6b (see FIG. 1) is connected to the outlet 18. A stirring blade (stirrer) 21 is accommodated inside the tubular portion 14 (see FIG. 2). The molten glass Gm flows into the inside of the tubular portion 14 through the inlet 17 from the inlet pipe 19, is homogenized by the stirring blade 21, and then flows out to the outlet pipe 20 through the outlet 18. In this case, the molten glass Gm flowing through the inside of the first transfer pipe P1 (stirring tank 6) is energized and heated by the current flowing from both electrode portions 15a and 16a to the tubular portion 14. An openable lid 22 is disposed above the upper end of the tubular portion 14 (above the upper flange portion 15), and the aforementioned lower flange portion 16 (blind flange) is disposed as the bottom wall at the lower end of the tubular portion 14. Further, the rotation axis 21a of the stirring blade 21 penetrates the lid 22 and protrudes upward.

[0036] An annular rib portion 24 extending along the circumferential direction is attached to the outer peripheral side of the tubular portion 14. In the present embodiment, the rib portions 24 are attached at a plurality of locations (four locations in the illustrated example) in the tube axis Z direction of the tubular portion 14. Each of these rib portions 24 is provided with a joint portion 24a in the middle of the circumferential direction. These joint portions 24a are joint portions formed by joining both ends of a plurality of circular (true circular) curved rib materials by welding or the like. These joint portions 24a are provided at the same location in the circumferential direction in the plurality of rib portions 24 and are aligned linearly along the tube axis Z direction. The inner peripheral portions of these rib portions 24 are joined to the outer peripheral surface of the tubular portion 14 by welding or the like over the entire circumferential length. The tubular portion 14 is provided with a joint portion 14a extending linearly along the tube axis Z direction. This joint portion 14a is a joint portion formed by joining both ends of a circular (true circular) curved tube material by welding or the like.

[0037] The tubular portion 14 and the rib portion 24 can be formed of platinum, a platinum alloy (such as a platinum-rhodium alloy, etc.), reinforced platinum, or a reinforced platinum alloy. Reinforced platinum has a metal structure in which zirconia or the like is dispersed in platinum, and the reinforced platinum alloy has a metal structure in which zirconia or the like is dispersed in a platinum alloy. The tubular portion 14 is preferably formed of platinum or a platinum alloy (such as a platinum-rhodium alloy, etc.), and the rib portion 24 is preferably formed of reinforced platinum or a reinforced platinum alloy in which zirconia or the like is dispersed in platinum or a platinum alloy. According to this, since the tubular portion 14 has lower brittleness than the rib portion 24, the thermal stress generated in the tubular portion 14 by energization heating can be reduced, and damage to the tubular portion 14 can be efficiently suppressed. Moreover, since the rib portion 24 has higher strength than the tubular portion 14, the effect of reducing the deformation of the tubular portion 14 by the rib portion 24 is improved. Note that both flange portions 15, 16 and both electrode portions 15a, 16a can be formed of platinum, a platinum alloy, reinforced platinum, a reinforced platinum alloy, nickel, or a nickel alloy. Both flange portions 15, 16 are fixed to one end and the other end in the tube axis Z direction of the tubular portion 14 by welding or the like, respectively.

[0038] The position of the joint portion 24a of the rib portion 24 and the position of the joint portion 14a of the tubular portion 14 are different in the circumferential direction of the tubular portion 14. In this case, since the joint portion 14a of the tubular portion 14 is a joint portion by welding or the like, its strength is low. Also, since the joint portion 24a of the rib portion 24 is also a joint portion by welding or the like, its strength is low. Therefore, when the positions of these two joint portions 14a and 24a overlap in the circumferential direction, the portions with insufficient strength against thermal expansion overlap in the circumferential direction between the tubular portion 14 and the rib portion 24, which becomes a factor causing damage such as cracks in the tubular portion 14 (its joint portion 14a). If the positions of the two joint portions 14a and 24a are different in the circumferential direction as in the configuration here, such a problem is less likely to occur, and the strength of the tubular portion 14 and thus the stirring tank 6 can be improved. Further, when the inflow pipe 19 expands thermally in the pipe axis Z1 direction and the outflow pipe 20 also expands thermally in the pipe axis Z2 direction, the first transfer pipe P1 (stirring tank 6) is pushed by the two pipes 19 and 20, so that its cross-sectional shape in plan view deforms from circular to elliptical and is likely to be damaged. Also in this regard, since the positions of the two joint portions 14a and 24a are different in the circumferential direction, such a problem is less likely to occur.

[0039] The position of the joint portion 14a of the tubular portion 14 and the positions of the inflow port 17 and the outflow port 18 are different in the circumferential direction of the tubular portion 14. According to this, when the inflow pipe 19 and the outflow pipe 20 expand thermally as described above, even if the first transfer pipe P1 is pushed by the two pipes 19 and 20, it is difficult for the pressing force to act on the joint portion 14a of the tubular portion 14. Therefore, damage to the tubular portion 14 and thus the first transfer pipe P1 can be efficiently avoided.

[0040] The position of the joint portion 24a of the rib portion 24 and the positions of the inflow port 17 and the outflow port 18 are different in the circumferential direction of the tubular portion 14. According to this, when the inflow pipe 19 and the outflow pipe 20 expand thermally as described above, even if the first transfer pipe P1 is pushed by the two pipes 19 and 20, it is difficult for the pressing force to act on the joint portion 24a of the rib portion 24. Therefore, damage to the rib portion 24 and thus the first transfer pipe P1 can be efficiently avoided.

[0041] Hereinafter, the configuration of the first transfer pipe P1 will be described in more detail with reference to FIG. 4. As shown in the figure, in the first transfer pipe P1, an inlet 17 and an outlet 18 face each other across the pipe axis Z of the tubular portion 14 in a plan view, and a joint portion 14a of the tubular portion 14 and a joint portion 24a of the rib portion 24 face each other across a virtual straight-line path (a path including the virtual straight line L) from the inlet 17 to the outlet 18 in a plan view. In the illustrated example, the inlet 17 and the outlet 18 are arranged at an interval of 180°, and both joint portions 14a and 24a are also arranged at an interval of 180°. And, a virtual straight-line path from the inlet 17 to the outlet 18 in a plan view and a virtual straight line connecting both joint portions 14a and 24a in a plan view are orthogonal to each other. According to this configuration, even if the first transfer pipe P1 is pushed by both pipes 19 and 20 due to thermal expansion, both joint portions 14a and 24a are both at positions sufficiently separated from the positions where the pressing force acts (the most separated positions in the illustrated example), so that damage to the first transfer pipe P1 is more reliably avoided. In the illustrated example, both electrode portions 15a and 16a are arranged at an interval of 180°. Moreover, the positions of both electrode portions 15a and 16a are different from the positions of both joint portions 14a and 24a in the circumferential direction. According to this configuration, adverse effects due to energization heating can be avoided. That is, at the circumferential positions of the tubular portion 14 corresponding to the attachment positions of both electrode portions 15a and 16a, the current density increases and the temperature becomes high, so it is easily damaged by heat. Therefore, when the position of one or both of both electrode portions 15a and 16a and the position of the joint portion 14a of the tubular portion 14 are overlapped in the circumferential direction, the tubular portion 14 and thus the stirring tank 6 are extremely likely to be damaged. According to this configuration, such a problem is less likely to occur. Also, the positions of both electrode portions 15a and 16a are different from the positions of both the inlet 17 and the outlet 18 in the circumferential direction. According to this configuration, damage to the stirring tank 6 can be more reliably suppressed. That is, since an inflow pipe 19 and an outflow pipe 20 are respectively connected to the inlet 17 and the outlet 18, the connection portions of the tubular portion 14 thereto have low strength. Therefore, when the positions of the inlet 17 and the outlet 18 and the positions of both electrode portions 15a and 16a that increase the current density of the tubular portion 14 are overlapped in the circumferential direction, the stirring tank 6 is more likely to be damaged. According to this configuration, such a problem is less likely to occur.

[0042] Here, regarding the first transfer pipe P1, if the positions of both joint portions 14a and 24a are different in the circumferential direction, it is not limited to the configurations shown in FIGS. 2 to 4. For example, both joint portions 14a and 24a may not be arranged at 180° intervals. In that case, it is preferable that the positions of both joint portions 14a and 24a are different from the positions of both the inlet 17 and the outlet 18 in the circumferential direction. The joint portions 24a of the plurality of rib portions 24 may be provided at different positions in the circumferential direction of the plurality of rib portions 24. Therefore, these joint portions 24a do not have to be aligned linearly along the pipe axis Z direction. In that case, the positions of all the joint portions 24a may be different in the circumferential direction, or the relationship may be such that the positions of some of the joint portions 24a and the positions of the remaining joint portions 24a are different in the circumferential direction (for example, a staggered relationship, etc.). Both electrode portions 15a and 16a do not have to be arranged at 180° intervals and may be at the same position in the circumferential direction. The position of either one or both of both joint portions 14a and 24a may overlap with the position of either one or both of both electrode portions 15a and 16a in the circumferential direction. The position of either one or both of the inlet 17 and the outlet 18 may overlap with the position of either one or both of both electrode portions 15a and 16a in the circumferential direction.

[0043] Next, the positional relationship between both joint portions 14a and 24a will be described in detail. As shown in FIG. 4, a straight line from the pipe axis Z to the joint portion 24a of the rib portion 24 is defined as L1, and a straight line from the pipe axis Z to the joint portion 14a of the tubular portion 14 is defined as L2, and the angle formed by both joint portions 14a and 24a is defined as α1. This angle α1 is preferably 45° or more, more preferably 90° or more, and even more preferably 135° or more. In other words, the joint portion 24a of the rib portion 24 is preferably provided at positions different by 45° or more with respect to both one side (arrow a1 direction side) and the other side (arrow b1 direction side) in the circumferential direction with respect to the joint portion 14a of the tubular portion 14, more preferably provided at positions different by 90° or more, and even more preferably provided at positions different by 135° or more. In this case, the joint portion 24a of the rib portion 24 is most preferably provided at positions different within a range of 10° or less with respect to both one side and the other side in the circumferential direction with respect to a virtual straight line passing through the pipe axis Z from the joint portion 14a of the tubular portion 14 (in other words, it is most preferable that the angle α1 is 170° or more). Note that the upper limit of the angle α1 is 180° or less.

[0044] Figs. 5 and 6 illustrate a transfer pipe P2 according to a second example (hereinafter referred to as the second transfer pipe P2). In the present embodiment, the second transfer pipe P2 constitutes the clarification tank 5 and the midstream connection pipe 9. Fig. 5 is a perspective view showing the second transfer pipe P2, and Fig. 6 is a longitudinal front view cut along the C-C line of Fig. 5. The differences between this second transfer pipe P2 and the above-described first transfer pipe P1 are that the pipe axis Z extends along the lateral direction (horizontal direction in the illustrated example), and an inlet 17k is formed at the upstream end of the tubular portion 14k and an outlet 18k is formed at the downstream end. Note that an upstream electrode portion 15ka protruding downward is integrally attached to an upstream flange portion 15k provided at the upstream side end of the tubular portion 14k. This upstream flange portion 15k and upstream electrode portion 15ka respectively correspond to the upper end flange portion 15 and upper end electrode portion 15a of the first transfer pipe P1. Further, a downstream electrode portion 16ka protruding upward is integrally attached to a downstream flange portion 16k provided at the downstream side end of the tubular portion 14k. This downstream flange portion 16k and downstream electrode portion 16ka respectively correspond to the lower end flange portion 16 and lower end electrode portion 16a of the first transfer pipe P1. Note that both the upstream flange portion 15k and the downstream flange portion 16k have openings corresponding to the inner peripheral surface of the tubular portion 14k. The joint portions 24ka of the plurality of rib portions 24k are provided at the central position in the circumferential direction from the top to the bottom on one side (right side in the illustrated example) of the tubular portion 14k. Further, the joint portion 14ka of the tubular portion 14k is provided at the central position in the circumferential direction from the top to the bottom on the other side (left side in the illustrated example) of the tubular portion 14k. Therefore, both joint portions 14ka and 24ka in the second transfer pipe P2 are arranged at an interval of 180° in the same manner as the first transfer pipe P1 (the configuration of the example shown in Figs. 2 to 4). If both joint portions 14ka and 24ka are provided at positions excluding the top and bottom of the tubular portion 14k in this way, the following advantages can be obtained. That is, when the molten glass Gm fills the inside of the tubular portion 14k, the molten glass Gm can reach the highest temperature around the top of the tubular portion 14k, so the top of the tubular portion 14k is likely to be damaged. Moreover, since air pockets are likely to occur in the molten glass Gm around the top of the tubular portion 14k, problems such as oxidation and thinning of the top of the tubular portion 14k are caused.In addition, when the presence of an air pocket or the non - filling of the tubular portion 14k with the molten glass Gm causes the periphery of the top of the tubular portion 14k to not come into contact with the molten glass Gm, the top of the tubular portion 14k itself becomes hotter and is more likely to be damaged. Therefore, it is preferable to provide both joint portions 14ka and 24ka excluding the top of the tubular portion 14k. Also, the bottom of the tubular portion 14k is a part where the influence of the self - weight of the molten glass is the greatest, so it is likely to be damaged. Therefore, it is preferable to provide both joint portions 14ka and 24ka excluding the bottom of the tubular portion 14. Other matters to be explained are the same as those explained for the first transfer pipe P1 described above.

[0045] FIGS. 7 and 8 illustrate a transfer pipe P3 (hereinafter referred to as the third transfer pipe P3) according to a third example. In the present embodiment, the third transfer pipe P3 constitutes the upstream connection pipe 8 and the cooling pipe 10, and in some cases, also constitutes the clarification tank 5. FIG. 7 is a perspective view showing the third transfer pipe P3, and FIG. 8 is a longitudinal front view cut along the line D - D of FIG. 7. The difference between this third transfer pipe P3 and the second transfer pipe P2 described above is that the downstream side of the tubular portion 14k is inclined upward by an angle β from the horizontal plane. In this case, both the upstream flange portion 15k and the downstream flange portion 16k are provided at the upstream end and the downstream end of the tubular portion 14k such that their end faces (planes) are along the vertical plane. Therefore, the inlet 17k and the outlet 18k of the tubular portion 14k form an oblong shape that is long in the vertical direction. On the other hand, the rib portion 24k is formed along a plane perpendicular to the pipe axis Z. Therefore, the shape of the rib portion 24k is circular (a perfect circle). Other matters to be explained are the same as those explained for the first transfer pipe P1 and the second transfer pipe P2 described above.

[0046] As described above, the manufacturing apparatus and the manufacturing method of the glass article according to the embodiment of the present invention have been described. However, the present invention is not limited to this, and various variations are possible without departing from the gist thereof.

[0047] For example, in the above embodiment, the present invention is applied to the transfer device used in manufacturing plate glass. However, the present invention may also be applied to the transfer device used in manufacturing glass articles other than plate glass (such as glass tubes and glass fibers).

[0048] In the above embodiment, the annular rib portions are provided at four positions in the tube axis direction of the tubular portion. However, they may be provided at five or more positions or three or fewer positions (even only one position).

[0049] In the above embodiment, the annular rib portion is attached to the outer peripheral side of the tubular portion. However, the annular rib portion may be attached to the inner peripheral side of the tubular portion.

[0050] In the above embodiment, the flange portions and the electrode portions are provided at both longitudinal ends of the tubular portion. However, instead of the ends, the flange portions and the electrode portions may be provided at the intermediate portion, or in addition to both ends, the flange portions and the electrode portions may be provided at the intermediate portion.

Explanation of Reference Numerals

[0051] 1 Manufacturing apparatus for glass article 2 Melting furnace 3 Transfer device 4 Forming device 5 Refining tank 6 Stirring tank 8 Upstream connecting pipe 9 Middle stream connecting pipe 10 Cooling pipe 14 Tubular portion 14a Joint portion of tubular portion 14k Tubular portion 14ka Joint portion of tubular portion 15 Flange portion (upper end flange portion) 15a Electrode portion (upper end electrode portion) 15k Flange portion (upstream side flange portion) 15ka Electrode portion (upstream side electrode portion) 16 Flange portion (lower end flange portion) 16a Electrode portion (lower end electrode portion) 16k Flange portion (downstream side flange portion) 16ka Electrode part (downstream electrode part) 17 Inlet 17k Inlet 18 Outlet 18k Outlet 19 Inflow pipe 20 Outflow pipe 24 Annular rib part 24a Joint part of the annular rib part 24k Annular rib part 24ka Joint part of the annular rib part Gm Molten glass Gr Glass ribbon P1 Transfer pipe (first transfer pipe) P2 Transfer pipe (second transfer pipe) P3 Transfer pipe (third transfer pipe) Z Pipe axis

Claims

1. A manufacturing apparatus for glass articles, comprising a transfer pipe for transferring molten glass, wherein the transfer pipe includes a tubular portion through which molten glass flows inside, and an electrode portion attached to the outer peripheral side of the tubular portion and passing an electric current through the tubular portion, the tubular portion has a joint portion extending along the tube axis direction, an annular rib portion is attached to the tubular portion, the rib portion has a joint portion in the middle of the circumferential direction of the tubular portion, and a manufacturing apparatus for glass articles, characterized in that the position of the joint portion of the tubular portion and the position of the joint portion of the rib portion are different in the circumferential direction of the tubular portion.

2. The manufacturing apparatus for glass articles according to claim 1, wherein the tubular portion is formed of platinum or a platinum alloy, and the rib portion is formed of reinforced platinum or a reinforced platinum alloy.

3. The transfer pipe constitutes a stirring tank in which the tube axis direction of the tubular portion is along the vertical direction, and an inflow pipe and an outflow pipe are respectively connected to the inflow port and the outflow port of the molten glass provided in the tubular portion from the outside. The manufacturing apparatus for glass articles according to claim 1 or 2.

4. The manufacturing apparatus for glass articles according to claim 3, wherein the position of the joint portion of the tubular portion and the positions of the inflow port and the outflow port are different in the circumferential direction of the tubular portion.

5. The manufacturing apparatus for glass articles according to claim 3 or 4, wherein the position of the joint portion of the rib portion and the positions of the inflow port and the outflow port are different in the circumferential direction of the tubular portion.

6. The position of the inflow port and the position of the outflow port face each other across the tube axis of the tubular portion in a plan view, and the position of the joint portion of the tubular portion and the position of the joint portion of the rib portion face each other across a virtual straight-line path from the inflow port to the outflow port in a plan view. The manufacturing apparatus for glass articles according to any one of claims 3 to 5.

7. A manufacturing method for glass articles, including a step of transferring molten glass using a transfer pipe included in the manufacturing apparatus according to any one of claims 1 to 6.

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