Glass article manufacturing method and manufacturing device

Abstract

The invention provides a manufacturing method and a manufacturing device for a glass article, which can detect position deviation in the width direction of a glass ribbon conveyed in the longitudinal direction. This method for manufacturing a glass article comprises: an imaging step (S31) in which an imaging device (16a, 16b) is used to image the ends (GRa, GRb) of a glass ribbon (GR) in the width direction (X) while transporting the glass ribbon (GR) in the longitudinal direction (Y); and a detection step (S32) for detecting the positions of the ends (GRa, GRb) of the glass ribbon (GR) on the basis of the image (19) captured by the imaging step (S31).

Description

Technical Field

[0001] The present invention relates to a method and apparatus for manufacturing glass articles such as glass sheets. Background Art

[0002] As is well known, glass sheets are used as components for displays such as liquid crystal displays and organic EL displays, as well as mobile devices such as smartphones. Down-draw methods are widely used as a method for manufacturing glass sheets. Examples of such down-draw methods include the overflow down-draw method and the slit down-draw method.

[0003] The overflow down-draw method involves flowing molten glass into an overflow trough located at the top of a forming body with a roughly wedge-shaped cross-section. The molten glass overflowing from the overflow trough flows down along the sidewalls of the forming body and fuses together at the bottom end of the forming body, thereby continuously forming a single glass ribbon. The slot down-draw method, on the other hand, involves forming a slit-shaped opening in the bottom wall of the forming body into which the molten glass is supplied, and allowing the molten glass to flow down through this opening, thereby continuously forming a single glass ribbon.

[0004] For example, Patent Document 1 discloses a method for producing a glass sheet using an overflow down-draw method. This method utilizes a forming zone where a glass ribbon is formed from molten glass using a forming body; an annealing zone where the glass ribbon descending from the forming zone is guided downward while annealing the glass ribbon; and a cooling zone where the glass ribbon passing through the annealing zone is cooled while being pulled downward by support rollers. The glass ribbon passing through the cooling zone is then obtained as a ribbon-shaped glass sheet (glass film) (see Claim 1 of this document).

[0005] In this production method, the glass ribbon is conveyed in the longitudinal direction by edge rollers provided in the forming zone, annealing rollers provided in the annealing zone, and support rollers provided in the cooling zone (see paragraphs 0032 to 0038 of the document).

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2022-91351 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] In conventional glass product manufacturing methods, during conveyance of a glass ribbon, the glass ribbon may meander along its width, causing positional deviation. When the glass ribbon undergoes positional deviation during conveyance, changes in warpage and strain in the glass ribbon may occur, leading to quality issues in the glass ribbon.

[0011] The present invention has been made in view of the above circumstances, and a technical object thereof is to detect positional deviation in the width direction of a glass ribbon conveyed in the longitudinal direction.

[0012] Solutions to Problems

[0013] (1) The present invention is a method for manufacturing a glass article for solving the above-mentioned problems, comprising: a forming step of forming a glass ribbon from molten glass; and an annealing step of annealing the formed glass ribbon in an annealing furnace while conveying the glass ribbon in a longitudinal direction, wherein:

[0014] The method for manufacturing a glass article includes: a photographing step of photographing an end portion of the glass ribbon in a width direction while the glass ribbon is conveyed in a longitudinal direction; and a detecting step of detecting a position of the end portion of the glass ribbon based on the image photographed in the photographing step.

[0015] According to this configuration, the position of the glass ribbon end is detected in the detection step based on the image of the glass ribbon end obtained in the imaging step. Therefore, if the glass ribbon is misaligned during transport, the misalignment can be detected based on the change in the position of the glass ribbon end. By detecting transport anomalies in the glass ribbon in this manner, quality anomalies caused by changes in warpage or strain in the glass ribbon can be detected early, allowing appropriate measures to be taken to eliminate the anomalies.

[0016] (2) In the method for manufacturing a glass article according to (1) above, in the photographing step, light may be irradiated toward the end portion of the glass ribbon using a lighting device.

[0017] According to this configuration, the end of the glass ribbon is illuminated by light from the lighting device, making the end of the glass ribbon darker or blacker. In the image captured by the imaging device, the position of the end of the glass ribbon can be easily detected based on the darker or blacker portion.

[0018] (3) In the method for manufacturing a glass article described in (1) or (2) above, in the detecting step, the position of the end portion of the glass ribbon may be detected based on one or more of the hue, chroma, and lightness of the end portion of the glass ribbon included in the image by using an image processing device.

[0019] According to this configuration, it is easy to identify the position of the end portion of the glass ribbon in an image including the end portion of the glass ribbon.

[0020] (4) In the method for manufacturing a glass article according to any one of (1) to (3), in the detecting step, a width of an ear portion included in the end portion of the glass ribbon may be detected based on the image captured in the capturing step.

[0021] The ear portions formed at the ends of a glass ribbon are thicker than the product portion (effective portion) in the center of the glass ribbon. When the width of these ear portions decreases, the strength of the glass ribbon ends decreases, potentially leading to breakage. Furthermore, when the width of the ear portions increases, this can cause poor cutting when the glass ribbon is cut in subsequent steps. According to the present invention, by detecting the width of the ear portions at the ends of the glass ribbon during the inspection step, ear abnormalities can be detected early and addressed appropriately.

[0022] (5) In the method for manufacturing a glass article described in (4) above, in the detecting step, the width of the ear portion may be detected based on one or more of hue, chroma, and lightness of the end portion of the glass ribbon included in the image by using an image processing device.

[0023] According to this configuration, in an image including the end portion of the glass ribbon, the width of the ear portion at the end portion of the glass ribbon can be easily identified.

[0024] (6) In the method for manufacturing a glass article according to any one of (1) to (5) above, the photographing step may be performed below the annealing furnace.

[0025] According to this configuration, by performing the imaging step at a position spaced downward from the annealing furnace, it is possible to prevent the imaging device used in the imaging step from malfunctioning due to the heat of the annealing furnace.

[0026] (7) In the method for manufacturing a glass article described in any one of (1) to (6) above, the method for manufacturing a glass article may include: a cooling step of cooling the glass ribbon that has undergone the annealing step while conveying it in the longitudinal direction; and a cutting step of cutting a glass sheet from the glass ribbon after the cooling step, wherein the photographing step is performed during the cooling step.

[0027] According to this configuration, the glass ribbon temperature during the cooling process is lower than that in the annealing furnace. Therefore, the imaging device used in the imaging process can be prevented from being exposed to high temperatures, thereby preventing malfunction of the imaging device. Furthermore, compared to performing the imaging process between the cooling process and the cutting process, the glass ribbon experiences less oscillation, making it easier to detect positional deviations of the glass ribbon. From this perspective, it is more preferable to perform the imaging process upstream of the cooling process (upstream of the cooling zone described below).

[0028] (8) In the method for manufacturing a glass article described in any one of (1) to (7) above, the method for manufacturing the glass article may include a determination step of determining whether the position of the end portion of the glass ribbon is good or bad, wherein in the determination step, when the position of the end portion of the glass ribbon exceeds a reference value, it is determined that an excessive positional deviation has occurred in the glass ribbon, and the method for manufacturing the glass article may include a response step of changing the conditions of the forming step and / or the annealing step when it is determined that the positional deviation of the glass ribbon is excessive.

[0029] According to this configuration, when excessive positional deviation of the glass ribbon is detected in the determination step, the excessive positional deviation can be eliminated by changing the conditions of the forming step and / or the annealing step.

[0030] (9) The present invention is a device for manufacturing glass articles for solving the above-mentioned problems, comprising: a forming device for forming a glass ribbon from molten glass; a conveying device for conveying the glass ribbon in the longitudinal direction; and an annealing furnace for annealing the glass ribbon conveyed by the conveying device, wherein the device for manufacturing glass articles comprises: a photographing device for photographing the widthwise end of the glass ribbon conveyed by the conveying device; and an image processing device for detecting the position of the end of the glass ribbon based on the image photographed by the photographing device.

[0031] According to this configuration, the image processing device detects the position of the glass ribbon end based on an image of the glass ribbon end captured by the imaging device. This allows the positional deviation of the glass ribbon during transport to be detected based on the change in position of the glass ribbon end. By detecting abnormalities in the transport of the glass ribbon in this manner, quality abnormalities caused by changes in warpage or strain in the glass ribbon can be detected early, allowing appropriate measures to be taken to eliminate these abnormalities.

[0032] Effects of the Invention

[0033] According to the present invention, positional deviation in the width direction of the glass ribbon conveyed in the longitudinal direction can be detected. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a cross-sectional view showing a glass plate manufacturing apparatus.

[0035] Figure 2 It is a front view showing the manufacturing apparatus of a glass plate.

[0036] Figure 3 yes Figure 2 Cross-sectional view of the III-III direction.

[0037] Figure 4It is a top view showing the imaging device and the lighting device.

[0038] Figure 5 A diagram showing an example of an image captured by a camera.

[0039] Figure 6 A diagram showing an example of an image captured by a camera.

[0040] Figure 7 is a flowchart illustrating a method for manufacturing a glass article.

[0041] Figure 8 This is a flowchart showing an inspection process in a method for manufacturing a glass article.

[0042] Description of Reference Numerals

[0043] 1 Glass product manufacturing device

[0044] 3 Annealing furnace

[0045] 6 Forming device

[0046] 8a First edge roller (handling device)

[0047] 8b Second edge roller (transport device)

[0048] 13a First transport roller (transport device)

[0049] 13b Second transport roller (transport device)

[0050] 14a First support roller (conveying device)

[0051] 14b Second support roller (conveying device)

[0052] 16a First camera

[0053] 16b Second camera

[0054] 17a First lighting device

[0055] 17b Second lighting device

[0056] 18 Image processing device

[0057] 19 images

[0058] GM Molten Glass

[0059] GR Glass Ribbon

[0060] First end of GRa glass ribbon

[0061] GRb Second end of the glass ribbon

[0062] L Light from lighting device

[0063] S1 forming process

[0064] S2 annealing process

[0065] S3 cooling process

[0066] S4 cutting process

[0067] S31 Shooting Process

[0068] S32 Inspection process

[0069] S33 Judgment process

[0070] TP Ear

[0071] X Width direction of glass ribbon

[0072] Y vertical

[0073] W Width of the ear. DETAILED DESCRIPTION

[0074] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Figures 1 to 8 One embodiment of the manufacturing apparatus and manufacturing method of the glass article of the present invention is shown.

[0075] like Figure 1 as well as Figure 2 As shown, a manufacturing apparatus 1 for a glass article includes: a forming furnace 2 for forming a glass ribbon GR from molten glass GM; an annealing furnace 3 for annealing (annealing treatment) the glass ribbon GR; a cooling zone 4 for cooling the glass ribbon GR to near room temperature; and a cutting device 5 arranged below the cooling zone 4.

[0076] The glass ribbon GR is a long, transparent glass sheet with a predetermined width. Hereinafter, one end of the glass ribbon GR in the width direction X is referred to as the first end GRa, and the other end of the glass ribbon GR in the width direction X is referred to as the second end GRb. In the following description, one principal surface of the glass ribbon GR is referred to as the first principal surface GR1, and the other principal surface is referred to as the second principal surface GR2.

[0077] like Figure 3 As shown, the first end GRa and the second end GRb of the glass ribbon GR include a tab portion TP having a thickness greater than that of an effective portion located in the center of the glass ribbon GR in the width direction X; and a non-effective portion formed between the effective portion and the tab portion TP. It should be noted that the effective portion refers to a portion corresponding to a glass sheet as a glass article cut from the glass ribbon GR, while the non-effective portion refers to a portion having a thickness less than that of the tab portion TP and being a non-product portion that is cut along with the tab portion TP.

[0078] A forming device 6 for forming a glass ribbon GR from molten glass GM by an overflow down-draw method is arranged in the internal space of the forming furnace 2. The forming device 6 includes a forming body 7 and edge rollers 8a and 8b.

[0079] The formed body 7 is made of, for example, alumina-based or zirconia-based refractory bricks, but the material of the formed body 7 is not limited to that of the present embodiment.

[0080] like Figure 1 as well as Figure 2 As shown, the forming body 7 has an overflow channel 9 for overflowing molten glass GM in its upper portion. Furthermore, the forming body 7 has a pair of sidewall surfaces 10 and 11 for flowing molten glass GM down and a lower end portion 12 for fusing molten glass GM flowing down on the pair of sidewall surfaces 10 and 11.

[0081] The edge rollers 8a and 8b include a first edge roller 8a that clamps the first end GRa of the glass ribbon GR, and a second edge roller 8b that clamps the second end GRb of the glass ribbon GR. The edge rollers 8a and 8b are disposed below the forming body 7 and comprise a roller pair that clamps the respective end portions GRa and GRb of the glass ribbon GR formed by the forming body 7. The roller pair includes a roller positioned on the first principal surface GR1 side of the glass ribbon GR, and a roller positioned on the second principal surface GR2 side of the glass ribbon GR.

[0082] The pair of rollers constituting the edge rollers 8a and 8b is configured to be independently movable along the thickness direction T of the glass ribbon GR. Thereby, the edge rollers 8a and 8b can adjust the clamping pressure with respect to the glass ribbon GR.

[0083] The annealing furnace 3 is provided below the forming furnace 2. The annealing furnace 3 anneals the glass ribbon GR sent downward from the forming furnace 2 and conveys it in the longitudinal direction Y. Figure 1 as well as Figure 2 As shown, multiple upper and lower conveying rollers 13a and 13b are arranged in the annealing furnace 3 to convey the glass ribbon GR. The conveying rollers 13a and 13b include a first conveying roller 13a arranged on the first end GRa side of the glass ribbon GR and a second conveying roller 13b arranged on the second end GRb side of the glass ribbon GR. Each conveying roller 13a and 13b holds the inactive portion of the glass ribbon GR inward from the ear portion TP of the glass ribbon GR without contacting the ear portion TP.

[0084] The conveying rollers 13a and 13b consist of a pair of rollers that clamp the end portions GRa and GRb of the glass ribbon GR. The roller pair includes a roller positioned on the first principal surface GR1 side of the glass ribbon GR and a roller positioned on the second principal surface GR2 side of the glass ribbon GR. Each roller is configured to be independently movable along the thickness direction T of the glass ribbon GR. This allows the conveying rollers 13a and 13b to adjust the clamping pressure on the glass ribbon GR.

[0085] The cooling zone 4 is located below the annealing furnace 3. Multiple vertical support rollers 14a and 14b are arranged in the cooling zone 4 to transport the glass ribbon GR. The support rollers 14a and 14b include a first support roller 14a positioned on the first end GRa side of the glass ribbon GR and a second support roller 14b positioned on the second end GRb side of the glass ribbon GR. Each support roller 14a and 14b holds the inactive portion of the glass ribbon GR, located inward of the ear portion TP, without contacting the ear portion TP of the glass ribbon GR.

[0086] The support rollers 14a and 14b are composed of a pair of rollers that clamp the end portions GRa and GRb of the glass ribbon GR. The roller pair includes a roller positioned on the first principal surface GR1 side of the glass ribbon GR and a roller positioned on the second principal surface GR2 side of the glass ribbon GR. Each roller is configured to be independently movable along the thickness direction T of the glass ribbon GR. This allows the support rollers 14a and 14b to adjust the clamping pressure on the glass ribbon GR.

[0087] like Figure 1 As shown, an inspection device 15 for inspecting the position of the glass ribbon GR is arranged in the cooling zone 4, more specifically, on the upstream side of the cooling zone 4. The inspection device 15 includes imaging devices 16a and 16b for imaging the respective end portions GRa and GRb of the glass ribbon GR, lighting devices 17a and 17b for irradiating light L toward the glass ribbon GR, and an image processing device 18.

[0088] like Figure 1 as well as Figure 2 As shown in FIG. 1 , the imaging devices 16a and 16b are arranged below the annealing furnace 3. The imaging devices 16a and 16b are arranged above the detection position DP of the glass ribbon GR. Therefore, the imaging devices 16a and 16b are arranged as shown in FIG. Figure 1 As shown in FIG. 1 , the imaging devices 16 a and 16 b are tilted downward. The present invention is not limited thereto, and the imaging devices 16 a and 16 b may be arranged in a horizontal posture.

[0089] The imaging devices 16a and 16b capture images of the end portions GRa and GRb at the detection position DP set in the middle of the glass ribbon GR conveyed in the longitudinal direction Y, and transmit the images to the image processing device 18. Figure 2 as well as Figure 3 As shown, the imaging devices 16a and 16b include a first imaging device 16a for imaging the first end portion GRa of the glass ribbon GR and a second imaging device 16b for imaging the second end portion GRb of the glass ribbon GR.

[0090] like Figure 3As shown, the first imaging device 16a is positioned inward of the first end GRa in the width direction X of the glass ribbon GR. Furthermore, the first imaging device 16a is positioned in an inclined position relative to the thickness direction T of the glass ribbon GR so as to capture a detection position DP of the first end GRa of the glass ribbon GR, which is located outward of the first imaging device 16a in the width direction X. The inclination angle θ1 of the first imaging device 16a relative to the thickness direction T of the glass ribbon GR is greater than 1° and less than 45°. It should be noted that the first imaging device 16a may also be positioned outward of the first end GRa in the width direction X of the glass ribbon GR. To ensure installation space without increasing the size of the annealing furnace 3, the first imaging device 16a is preferably positioned inward of the first end GRa in the width direction X of the glass ribbon GR.

[0091] like Figure 3 As shown, the second imaging device 16b is positioned inward of the second end GRb in the width direction X of the glass ribbon GR. Furthermore, the second imaging device 16b is positioned in an inclined position relative to the thickness direction T of the glass ribbon GR so as to capture a detection position DP of the second end GRb of the glass ribbon GR, which is located outward of the second imaging device 16b in the width direction X. The inclination angle θ2 of the second imaging device 16b relative to the thickness direction T of the glass ribbon GR is greater than 1° and less than 45°. It should be noted that the second imaging device 16b may also be positioned outward of the second end GRb in the width direction X of the glass ribbon GR. To ensure installation space without increasing the size of the annealing lehr 3, the second imaging device 16b is preferably positioned inward of the second end GRb in the width direction X of the glass ribbon GR.

[0092] The arrangement of the imaging devices 16a and 16b is not limited to Figure 3 For example, Figure 4 As shown, the first imaging device 16a and the second imaging device 16b may be arranged in a posture parallel to the thickness direction T of the glass ribbon GR. In this case, the first lighting device 17a may be arranged in an inclined posture at a position outside the first imaging device 16a in the width direction X, and the second lighting device 17b may be arranged in an inclined posture at a position outside the second imaging device 16b in the width direction X. From the perspective of ensuring installation space without increasing the size of the annealing furnace 3, it is preferable that the first lighting device 17a is arranged in an inclined posture at a position inside the width direction X than the first imaging device 16a, and the second lighting device 17b is arranged in an inclined posture at a position inside the width direction X than the second imaging device 16b.

[0093] like Figure 1 as well as Figure 2 As shown, lighting devices 17a and 17b are arranged below the annealing furnace 3. The lighting devices 17a and 17b include a first lighting device 17a for imaging by the first imaging device 16a and a second lighting device 17b for imaging by the second imaging device 16b.

[0094] like Figure 3 As shown, the first lighting device 17a and the second lighting device 17b each include a plurality of illuminating devices. Specifically, each lighting device 17a, 17b includes a lighting device that is disposed on the first principal surface GR1 side of the glass ribbon GR and irradiates light L toward the first principal surface GR1, and a lighting device that is disposed on the second principal surface GR2 side of the glass ribbon GR and irradiates light L toward the second principal surface GR2.

[0095] like Figure 1 As shown, each lighting device 17a, 17b is arranged so as to horizontally irradiate light L. However, the present invention is not limited thereto, and each lighting device 17a, 17b may be configured so as to irradiate light L obliquely downward, similarly to each imaging device 16a, 16b.

[0096] like Figure 3 As shown, the lighting devices 17a and 17b are arranged so as to irradiate light L along the thickness direction T of the glass ribbon GR. The first lighting device 17a is arranged outside the first imaging device 16a in the width direction X. The second lighting device 17b is arranged outside the second imaging device 16b in the width direction X.

[0097] The image processing device 18 can detect the positions of the ends GRa and GRb of the glass ribbon GR based on the images captured by the imaging devices 16a and 16b. The image processing device 18 is a computer with built-in image analysis software. The image processing device 18 includes a monitor that displays images sent from the imaging devices 16a and 16b.

[0098] Figure 5 as well as Figure 6 The image displayed on the monitor of the image processing device 18 is schematically shown. Figure 5 as well as Figure 6 In the example of FIG, an image 19 including the second end portion GRb of the glass ribbon GR is illustrated. The image 19 includes the ear portion TP of the second end portion GRb of the glass ribbon GR and a non-effective portion formed integrally with the ear portion TP.

[0099] The image processing device 18 can display the measurement area 20 in an overlapping manner within the range of the image 19. Figure 5As shown, one measurement area 20 displayed in the image 19 is configured as a rectangular frame along the width direction X. The image processing device 18 can detect the positions of the ends GRa and GRb of the glass ribbon GR and the width W of the ear portion TP within the measurement area 20 (inside the frame).

[0100] Specifically, the image processing device 18 detects the positions of the edges TPa and TPb of the ear TP within the measurement area 20. The edges TPa and TPb of the ear TP include a first edge TPa located outside in the width direction X and a second edge TPb located inside the first edge TPa in the width direction X. The image processing device 18 detects the position of the first edge TPa within the measurement area 20 as the position of the second end GRb. Furthermore, by detecting the positions of the first and second edges TPa and TPb, the image processing device 18 can detect the distance between the first and second edges TPa and TPb in the width direction X, i.e., the width W of the ear TP.

[0101] exist Figure 6 In the example shown, image 19 includes two measurement areas 20a and 20b. Hereinafter, one of the two measurement areas 20a and 20b will be referred to as the first measurement area 20a, and the other as the second measurement area 20b. The first measurement area 20a can detect the position of a first edge TPa of the ear TP. The second measurement area 20b can detect the position of a second edge TPb of the ear TP.

[0102] The edge rollers 8a and 8b of the forming device 6, the conveying rollers 13a and 13b of the annealing furnace 3, and the support rollers 14a and 14b of the cooling zone 4 constitute a conveying device for conveying the glass ribbon GR in the longitudinal direction Y.

[0103] like Figure 1 As shown, the cutting device 5 is provided below the cooling zone 4. The cutting device 5 includes a scribing device (not shown), a contact portion 21, and a stress applying portion 22.

[0104] The scoring device forms scored lines SL on the first main surface GR1 of the glass ribbon GR along the width direction X. The scoring device includes, for example, a cutter wheel for forming the scored lines SL. The scoring device is not limited to the cutter wheel, and the scored lines SL may be formed by other methods such as laser irradiation.

[0105] The contact portion 21 supports the second main surface GR2 of the glass ribbon GR at a position corresponding to the scribed line SL. The contact portion 21 is composed of a plate-like body (platform) having a contact surface that contacts the second main surface GR2 of the glass ribbon GR along the width direction X of the glass ribbon GR while following the descending glass ribbon GR.

[0106] The stress-applying unit 22 holds the portion of the glass ribbon GR corresponding to the glass sheet GF to be cut (the portion below the scribed line SL) and applies bending stress to the scribed line SL. The stress-applying unit 22 includes gripping units (e.g., chucks) for gripping the end portions GRa and GRb of the glass ribbon GR.

[0107] Hereinafter, a method for manufacturing a glass plate GF as a glass article using the manufacturing apparatus 1 having the above-mentioned structure will be described. Figure 7 As shown, the method includes a forming step S1 , an annealing step S2 , a cooling step S3 and a cutting step S4 .

[0108] like Figure 1 As shown, in the forming step S1, the glass ribbon GR is continuously formed from the molten glass GM by the forming device 6. The forming body 7 causes the molten glass GM to overflow from the overflow channel 9 and flow down along the side wall surfaces 10 and 11 on both sides of the forming body 7.

[0109] Furthermore, the forming body 7 causes the flowing molten glass GM to merge (join) at the lower end portion 12. Thus, a glass ribbon GR having a predetermined width is formed. The edge rollers 8a, 8b feed the glass ribbon GR downward while holding the respective ends GRa, GRb of the glass ribbon GR with a predetermined pressure so as to suppress shrinkage in the width direction X of the glass ribbon GR.

[0110] In the annealing step S2, the glass ribbon GR is conveyed downward by the conveying rollers 13a and 13b in the annealing furnace 3. A predetermined temperature gradient is set in the annealing furnace 3, and the glass ribbon GR is annealed while passing through the annealing furnace 3.

[0111] In the cooling step S3 after the annealing step S2 , the glass ribbon GR passes through the cooling zone 4 while being conveyed in the longitudinal direction Y in a state where tension is applied by the support rollers 14 a and 14 b , and is cooled to near room temperature.

[0112] During the execution of the cooling step S3, an inspection step is performed to inspect the position of the glass ribbon GR passing through the cooling zone 4. Figure 8 As shown, the inspection process includes a photographing process S31 , a detection process S32 , and a determination process S33 .

[0113] In the imaging step S31, the end portions GRa and GRb of the glass ribbon GR are imaged by the imaging devices 16a and 16b while the glass ribbon GR is conveyed in the longitudinal direction Y, and images 19 thereof are acquired. In the imaging step S31, the end portions GRa and GRb of the glass ribbon GR are irradiated with light L by the lighting devices 17a and 17b.

[0114] The photographing step S31 is performed so that the ear portions TP of the ends GRa and GRb of the glass ribbon GR can be easily detected in the subsequent detection step S32 in the acquired image 19. That is, the positions and postures of the photographing devices 16a and 16b and the irradiation angles of the irradiation light L of the lighting devices 17a and 17b are arranged so as to use Figure 3 or Figure 4 The reason why the edges TPa and TPb of the ear TP appear darker or blacker is speculated to be due to light reflection and shadows formed by the unevenness of the ear TP.

[0115] In the detection step S32, the image processing device 18 detects the positions of the end portions GRa and GRb of the glass ribbon GR (the positions of the first edges TPa of the tabs TP) based on the image 19 captured in the capturing step S31. Furthermore, the image processing device 18 detects the width W of the tabs TP at each of the end portions GRa and GRb of the glass ribbon GR based on the image 19 of the glass ribbon GR received from the imaging devices 16a and 16b.

[0116] In the detection step S32, the image processing device 18 detects the position and width W of the ear portion TP based on one or more of the hue, saturation, and lightness of each end portion GRa, GRb of the glass ribbon GR included in the image 19. Figure 5 as well as Figure 6 As shown, in the image 19 captured in the capturing step S31, the first edge TPa and the second edge TPb of the ear TP at each end GRa and GRb are displayed in low-brightness black. In contrast, portions of the ear TP other than the edges TPa and TPb are displayed in high-brightness. Based on these black portions, the image processing device 18 can accurately detect the position and width W of each edge TPa and TPb of the ear TP.

[0117] In the determination step S33, the quality of the positions of the end portions GRa and GRb of the glass ribbon GR is determined by the image processing device 18. In the determination step S33, the image processing device 18 determines that excessive positional deviation has occurred in the glass ribbon GR when the positions of the end portions GRa and GRb of the glass ribbon GR exceed a reference value.

[0118] Furthermore, in the determination step S33, the image processing device 18 determines the quality of the ear portion TP at each end portion GRa or GRb of the glass ribbon GR. Specifically, the image processing device 18 compares the detected width W of the ear portion TP with a reference value (threshold value). The reference value includes a first reference value, which is the maximum allowable value for the width W of the ear portion TP, and a second reference value, which is the minimum allowable value for the width W of the ear portion TP.

[0119] The image processing device 18 compares the detected width W of the ear TP with a first reference value. If the width W of the ear TP exceeds the first reference value, the image processing device 18 determines that the width W of the ear TP is abnormal. The image processing device 18 compares the detected width W of the ear TP with a second reference value. If the width W of the ear TP is less than the second reference value, the image processing device 18 determines that the width W of the ear TP is abnormal. The image processing device 18 can display the determination result (normal or abnormal) on a monitor.

[0120] This method includes a countermeasure step of changing the conditions of the forming step S1 and / or the annealing step S2 when an abnormality in the position of the glass ribbon GR (excessive positional deviation) or an abnormality in the width W of the ear portion TP is detected in the determining step S33 .

[0121] For example, in the response process, in order to eliminate the positional deviation caused by the detected meandering of the glass ribbon GR and return the glass ribbon GR to a desired position, the position of the glass ribbon GR is adjusted by the conveying device (edge rollers 8a, 8b, conveying rollers 13a, 13b, support rollers 14a, 14b).

[0122] Specifically, as a response process, the rotation speed of the edge rollers 8a and 8b is adjusted, the clamping pressure of the glass ribbon GR clamped by the edge rollers 8a and 8b is adjusted, the rotation speed of the conveying rollers 13a and 13b in the annealing furnace 3 is adjusted, the clamping pressure of the glass ribbon GR clamped by the conveying rollers 13a and 13b is adjusted, or the rotation speed of the support rollers 14a and 14b in the cooling area 4 is adjusted, the clamping pressure of the glass ribbon GR clamped by the support rollers 14a and 14b is adjusted, etc. are performed.

[0123] The following, such as Figure 5 As shown, the detection step S32, the determination step S33, and the response step will be described in detail by taking the case where the second end GRb of the glass ribbon GR moves to the outer side X1 in the width direction X as an example. Figure 5 As shown, when the second end GRb of the glass ribbon GR moves from the appropriate position indicated by the solid line to the position indicated by the two-dot chain line, the image processing device 18 calculates the moving distance D of the second end GRb (detection step S32 ).

[0124] Then, the image processing device 18 starts the determination step S33 and compares the calculated movement distance D of the second end portion GRb with a reference value (threshold value). If the movement distance D of the second end portion GRb exceeds the reference value, the image processing device 18 determines that an abnormal positional deviation has occurred in the glass ribbon GR.

[0125] When an abnormal positional deviation of the glass ribbon GR is detected, the manager of the manufacturing apparatus 1 executes a countermeasure process to return the glass ribbon GR to its proper position. This is not limiting; the countermeasure process may also be executed automatically by a control device. In the countermeasure process, the following process is performed to return the glass ribbon GR, which has moved to the outer side X1 in the width direction X, to its original proper position.

[0126] For example, in the countermeasure process, the manufacturing apparatus 1 increases the rotational speed of the first edge roller 8a, the first conveying roller 13a, and the first support roller 14a. This causes the glass ribbon GR to be pulled toward the first edge roller 8a, the first conveying roller 13a, and the first support roller 14a. As another process, the manufacturing apparatus 1 increases the clamping pressure applied to the glass ribbon GR by the first edge roller 8a, the first conveying roller 13a, and the first support roller 14a. This causes the glass ribbon GR to be pulled toward the first edge roller 8a, the first conveying roller 13a, and the first support roller 14a. In this way, the glass ribbon GR that has excessively moved outward X1 in the width direction X can be pulled back to its original proper position.

[0127] The cutting step S4 is a step for cutting a glass sheet GF from the glass ribbon GR after the cooling step S3. The cutting step S4 includes a first cutting step and a second cutting step. In the first cutting step, the cutting device 5 cuts the midway portion of the glass ribbon GR along the width direction X, thereby cutting out a glass sheet GF of a predetermined size. Specifically, in the first cutting step, a scoring device forms a score line SL along the width direction X in the midway portion of the downwardly moving glass ribbon GR (scoring step), and then a portion of the glass ribbon GR is broken along the score line SL to form a single glass sheet GF (breaking step).

[0128] During the scoring process, the cutter wheel of the scoring device forms a score line SL along the width direction X of the glass ribbon GR while following the descending glass ribbon GR. During the breaking process, the stress-applying unit 22 operates to bend the glass ribbon GR using the contact portion 21 as a fulcrum while following the descending glass ribbon GR. This operation of the stress-applying unit 22 applies bending stress to the score line SL. As a result, the glass ribbon GR breaks along the score line SL in the width direction X, and a glass sheet GF is cut from the glass ribbon GR.

[0129] In the second cutting step, the ends of the glass sheet GF in the width direction corresponding to the ends GRa and GRb of the glass ribbon GR are cut and removed by a cutting device (not shown), thereby forming a rectangular glass sheet GF.

[0130] According to the manufacturing device 1 and manufacturing method of the glass article of the present embodiment described above, the positions of the respective ends GRa and GRb can be detected in the detection step S32 (image processing device 18) based on the images 19 of the respective ends GRa and GRb of the glass ribbon GR acquired in the imaging step S31 (imaging devices 16a and 16b).

[0131] Thus, when the glass ribbon GR is misaligned during conveyance, the misalignment can be detected based on changes in the positions of the ends GRa and GRb of the glass ribbon GR. By detecting conveyance anomalies of the glass ribbon GR in this manner, quality anomalies caused by changes in the warpage or strain of the glass ribbon GR can be detected early, and appropriate measures can be taken to eliminate the anomalies.

[0132] It should be noted that the present invention is not limited to the configuration of the above-described embodiment, nor is it limited to the above-described effects. The present invention can be modified in various ways without departing from the spirit of the present invention.

[0133] In the above embodiment, the method of cutting the glass ribbon GR to produce the glass sheet GF has been described, but the present invention is not limited to this example. For example, the present invention can also be applied to the case of producing a glass roll by winding the glass ribbon GR into a roll.

[0134] In the above embodiment, an example of manufacturing a glass article by the overflow down-draw method is shown, but the present invention is not limited thereto. For example, the present invention can also manufacture a glass article by the slot down-draw method.

[0135] In the above embodiment, an example is shown in which the imaging step S31 is performed by the imaging devices 16a, 16b and the lighting devices 17a, 17b installed in the cooling area 4, but the present invention is not limited to this structure. The imaging step S31 can also be performed by the imaging devices 16a, 16b and the lighting devices 17a, 17b installed in the annealing furnace 3. Alternatively, the imaging step S31 can also be performed by the imaging devices 16a, 16b and the lighting devices 17a, 17b installed between the cooling area 4 and the cutting device 5.

Claims

1. A method for manufacturing a glass article, comprising: a forming process for forming a glass ribbon from molten glass; and an annealing step, wherein the formed glass ribbon is annealed in an annealing furnace while being conveyed in the longitudinal direction, wherein The method for manufacturing a glass article includes: a photographing step of photographing an end portion of the glass ribbon in a width direction while the glass ribbon is conveyed in a longitudinal direction; and a detecting step of detecting a position of the end portion of the glass ribbon based on the image photographed in the photographing step.

2. The method for manufacturing a glass article according to claim 1, wherein: In the imaging step, light is irradiated toward the end portion of the glass ribbon using a lighting device.

3. The method for manufacturing a glass article according to claim 1 or 2, wherein: In the detecting step, the position of the end portion of the glass ribbon included in the image is detected based on one or more of hue, chroma, and lightness using an image processing device.

4. The method for manufacturing a glass article according to claim 1 or 2, wherein: In the detecting step, the width of the ear portion included in the end portion of the glass ribbon is detected based on the image captured in the capturing step.

5. The method for manufacturing a glass article according to claim 4, wherein: In the detecting step, the width of the ear portion is detected based on one or more of hue, chroma, and lightness of the end portion of the glass ribbon included in the image using an image processing device.

6. The method for manufacturing a glass article according to claim 1 or 2, wherein: The photographing step is performed below the annealing furnace.

7. The method for manufacturing a glass article according to claim 1 or 2, wherein: The method for manufacturing a glass article comprises: a cooling step of cooling the glass ribbon that has undergone the annealing step while conveying it in the longitudinal direction; and a cutting step of cutting a glass sheet from the glass ribbon after the cooling step. The photographing step is performed during the cooling step.

8. The method for manufacturing a glass article according to claim 1 or 2, wherein: The method for manufacturing a glass article includes a step of determining whether the position of the end portion of the glass ribbon is good or bad. In the determination step, when the position of the end portion of the glass ribbon exceeds a reference value, it is determined that an excessive positional deviation has occurred in the glass ribbon. The method for manufacturing a glass article includes a countermeasure step of changing the conditions of the forming step and / or the annealing step when it is determined that the positional deviation of the glass ribbon is excessive.

9. A device for manufacturing a glass article, comprising: a forming device for forming a glass ribbon from molten glass; a conveying device for conveying the glass ribbon in a longitudinal direction; and an annealing furnace for annealing the glass ribbon conveyed by the conveying device, wherein: The manufacturing apparatus for a glass article includes: an imaging device that images an end portion in the width direction of the glass ribbon conveyed by the conveying device; and an image processing device that detects a position of the end portion of the glass ribbon based on the image captured by the imaging device.

Images