Glass sheet manufacturing method and manufacturing apparatus thereof

Abstract

The present invention includes: a first cutting step of cutting a glass ribbon (G) that is continuously moved downward while being shaped in a shaping area (11) in a width direction to cut out a glass sheet; and a second cutting step of cutting the glass ribbon (G) using a device (3) having a structure different from that of a device (2) used in the first cutting step without performing the first cutting step, in which a cutting state of the glass ribbon (G) is checked by a sensor (35) and a cutting process is performed on the glass ribbon (G) based on a result of the checking by the sensor (35).

Description

Technical Field

[0001] The present invention relates to glass plate manufacturing technology, and more specifically, to a technology for performing a first cut to cut a glass plate by cutting a glass strip that moves continuously downward while being formed, and a second cut to cut the glass strip without performing the first cut. Background Technology

[0002] In the field of glass manufacturing, it is known to perform a first cutting process that cuts a glass strip that moves continuously downwards in a forming zone to a predetermined length along the width direction, thereby sequentially cutting out glass sheets. In this case, since the melting furnace and other equipment of the glass manufacturing equipment usually operate continuously, the glass strip generally continues to form even if the device used to perform the first cutting process is unavailable for maintenance, etc. Therefore, even if the first cutting process is not performed, it is necessary to cut and recycle the continuously forming glass strip.

[0003] To address this requirement, for example, Patent Document 1 discloses a second cutting process that cuts the glass strip using a device with a different structure than the device in the first cutting process, without performing the first cutting process. The device used in this second cutting process includes: a holding member that holds the glass strip; a pressing member that applies stress to the glass strip while it is held by the holding member; and an engraving member that engraves engraving lines on the stress-applying portion of the glass strip.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Chinese Utility Model Announcement No. 205473369 Specification Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] The device used in the second cutting process in Patent Document 1 has a simpler structure than the device used in the first cutting process (see paragraph 0005 of that document, etc.). However, when using this device, it is easy to cause poor cutting or failure to cut.

[0009] For example, during the continuous downward movement of the glass strip, the lower end of the glass strip may become caught in a component of the aforementioned device (e.g., a pressing member) or collide with the end of the glass strip's movement path. As a result, cracks may propagate along the vertical direction of the glass strip, leading to longitudinal fractures or other undesirable conditions.

[0010] Based on the above viewpoints, the objective of the present invention is to address situations such as poor cutting or inability to cut properly and prevent longitudinal breakage from occurring when a second cutting process is performed on a glass strip that moves continuously downward while being formed, instead of the first cutting process.

[0011] Solution for solving the problem

[0012] The first aspect of the present invention, made to solve the aforementioned problems, is a method for manufacturing a glass plate, comprising: a first cutting step, wherein a glass strip that moves continuously downward while being formed in a forming zone is cut along its width direction to produce a glass plate; and a second cutting step, wherein, when the first cutting step is not performed, the glass strip is cut using a device with a different structure than the device used in the first cutting step, wherein the glass plate manufacturing method is characterized in that, in the second cutting step, the state of the glass strip is checked using a sensor, and the cutting process of the glass strip is performed based on the check result of the sensor.

[0013] According to this structure, when the second cutting process is performed in place of the first cutting process, the condition of the glass strip is checked using a sensor, thus enabling appropriate handling of situations such as poor cutting or inability to cut. Specifically, for example, if a poor cutting or inability to cut occurs during the previous cutting process, the sensor quickly and accurately detects this situation and reflects the detection result to the cutting process. Therefore, during the cutting process, an appropriate cut can be performed so that the lower end of the glass strip does not become an obstacle. As a result, longitudinal breakage of the glass strip can be prevented.

[0014] In this structure, the sensor may also check whether there is a downward protrusion in the glass strip.

[0015] In this way, even if there is a protrusion that protrudes downwards from the glass strip in cases of poor cutting or inability to cut, the protrusion is detected by the sensor and the detection result is reflected in the cutting process. Therefore, the longitudinal breakage of the glass strip caused by the presence of the protrusion can be effectively prevented.

[0016] In the above structure, the sensor may also be provided in multiple locations corresponding to multiple parts in the width direction of the glass strip.

[0017] In this way, because multiple sensors are used to check the cutting status at multiple points along the width of the glass strip, the inspection performed by the sensors is detailed and highly accurate.

[0018] In this structure, the cutting process can also be performed in different ways depending on the different inspection results of the multiple sensors.

[0019] In this way, the cutting process can be carried out in different ways depending on the different cutting states detected by multiple sensors, so that the state of each part can be taken into account to perform the cutting process appropriately.

[0020] In the aforementioned structure, it is also possible that the multiple sensors have an inspection area at a position where a predetermined length is separated downward from the cutting position where the cutting process is performed in the second cutting step, and obtain a first inspection result based on the multiple sensors during a first period until the glass strip reaches the inspection area.

[0021] In this way, by comparing the glass ribbon with a case where it has undergone normal cutting at the cut position, it is possible to obtain results from multiple sensors inspecting the state of multiple parts of the glass ribbon. Specifically, by obtaining the first detection result in the first period, information about the lower end of the glass ribbon can be obtained.

[0022] In this structure, if none of the multiple sensors detect the glass strip in the first period, a second inspection result based on the multiple sensors is obtained in the second period following the first period. If all of the multiple sensors detect the glass strip in the second period, the glass strip is cut off along its entire width as part of the cutting process.

[0023] Here, the situation where all sensors fail to detect the glass strip in the first period refers to a situation where the glass strip has undergone normal cutting at the cutting position or where the cut end of the glass strip is located above the cutting position after cutting. Upon obtaining this information, a waiting period is initiated in the second period until all sensors detect the presence of the glass strip. If all sensors detect this situation, subsequent cutting processing is performed on the glass strip. Waiting until all sensors detect the glass strip is done to properly cut the glass strip across its entire width in the subsequent cutting process. Based on this structure, the glass strip can be cut to an appropriate length (e.g., a pre-set length).

[0024] In the aforementioned structure, it is also possible that, if all of the multiple sensors detect the glass strip in the first period, the glass strip is cut off along its entire width as part of the cutting process.

[0025] Here, if all multiple sensors detect the glass strip in the first phase, a situation arises where the initial cutting process cannot be completed. Upon obtaining this information, it is preferable to perform the cutting process immediately after sensor detection. This prevents the lower end of the glass strip from unduly elongating downwards over the entire length.

[0026] In the aforementioned structure, if two or more of the multiple sensors detect the glass strip in the first period and one or more sensors fail to detect the glass strip, a second inspection result based on the multiple sensors is obtained in the second period following the first period. In the second period, a waiting period is maintained until one or more sensors detect the glass strip. If one or more sensors detect the glass strip in the second period, the glass strip is cut off along its entire width as part of the cutting process.

[0027] The reason for not immediately cutting the glass strip when it is detected in two or more locations along the width direction in the first period is that cutting across the entire width length ensures ease and reliability of the cutting action. In this case, waiting in the second period until more than one sensor detects the glass strip is to wait until the situation becomes suitable for properly cutting the glass strip across the entire width length through the cutting process.

[0028] In the aforementioned structure, bending stress may also be applied to the area of ​​the glass strip to be cut when the glass strip is cut across its entire width as part of the cutting process.

[0029] In this way, bending stress can be effectively utilized to cut the glass strip across its entire width, enabling a smooth and reliable cutting process.

[0030] In the aforementioned structure, if one of the multiple sensors detects the glass strip in the first period and more than one other sensor does not detect the glass strip, the cutting process may involve cutting only a portion of the glass strip in the width direction corresponding to the one sensor.

[0031] In this way, if the glass strip is detected in only one of several locations in the width direction during the first phase, only that location of the glass strip is cut. Therefore, compared to cutting the glass strip over its entire width, it can be cut easily and quickly.

[0032] In this structure, the portion of the glass strip in the width direction can also be an end of the glass strip in the width direction.

[0033] Here, the glass strip has ears at both ends in the width direction. These ears are thicker than their central side region, making it easy to create long, narrow protrusions pointing downwards. When such a protrusion occurs at one end in the width direction, it can be cut off as early as possible. This allows for efficient cutting off of protrusions that could become obstacles.

[0034] In these structures, it is also possible that when only a portion of the glass strip in the width direction is cut as the cutting process, bending stress is not applied to the area of ​​the glass strip that should be cut.

[0035] In this way, since the effort of applying bending stress is eliminated, the cutting process can be carried out earlier and more easily.

[0036] A second aspect of the present invention, made to solve the aforementioned problems, is a glass sheet manufacturing apparatus comprising: a first cutting device that cuts a glass strip that moves continuously downward in a forming zone along its width direction to produce a glass sheet; and a second cutting device that, when not using the first cutting device, has a different structure from the first cutting device and cuts the glass strip, characterized in that the second cutting device is configured to use a sensor to check the state of the glass strip and perform the cutting process of the glass strip based on the check result of the sensor.

[0037] According to this scheme, the same effect as the described manufacturing method with the same structure as the manufacturing apparatus can be obtained.

[0038] Invention Effects

[0039] According to the present invention, even if a second cutting process is performed instead of the first cutting process when the glass strip that moves continuously downward during forming is being cut, resulting in poor cutting or inability to cut, these situations can be appropriately addressed to prevent longitudinal cracking from occurring. Attached Figure Description

[0040] Figure 1 This is a side view showing the overall structure of a glass plate manufacturing apparatus according to an embodiment of the present invention.

[0041] Figure 2 This is a schematic front view showing the main parts of a glass plate manufacturing apparatus according to an embodiment of the present invention.

[0042] Figure 3 This is an enlarged schematic top view of the second cutting device in a glass plate manufacturing apparatus according to an embodiment of the present invention.

[0043] Figure 4This is an enlarged schematic top view of the second cutting device in a glass plate manufacturing apparatus according to an embodiment of the present invention.

[0044] Figure 5 This is an enlarged side view of the second cutting device in a glass plate manufacturing apparatus according to an embodiment of the present invention.

[0045] Figure 6 This is a schematic front view showing the basic structure of the glass strip being cut by the second cutting device in a glass sheet manufacturing apparatus using an embodiment of the present invention.

[0046] Figure 7a This is a schematic front view showing a first example of how a glass strip is cut by a second cutting device in a glass sheet manufacturing apparatus using an embodiment of the present invention.

[0047] Figure 7b This is a schematic front view showing a first example of how a glass strip is cut by a second cutting device in a glass sheet manufacturing apparatus using an embodiment of the present invention.

[0048] Figure 8 This is a schematic front view showing a second example of how a glass strip is cut by a second cutting device in a glass sheet manufacturing apparatus using an embodiment of the present invention.

[0049] Figure 9a This is a summary front view showing a third example of how the glass strip is cut by the second cutting device in a glass sheet manufacturing apparatus using an embodiment of the present invention.

[0050] Figure 9b This is a summary front view showing a third example of how the glass strip is cut by the second cutting device in a glass sheet manufacturing apparatus using an embodiment of the present invention.

[0051] Figure 10a This is a schematic front view showing a fourth example of how the second cutting device in a glass sheet manufacturing apparatus using an embodiment of the present invention cuts a glass strip.

[0052] Figure 10b This is a schematic front view showing a fourth example of how the second cutting device in a glass sheet manufacturing apparatus using an embodiment of the present invention cuts a glass strip.

[0053] Figure 11a This is a schematic front view showing a fifth example of how the second cutting device in a glass sheet manufacturing apparatus using an embodiment of the present invention cuts a glass strip.

[0054] Figure 11bThis is a schematic front view showing a fifth example of how the second cutting device in a glass sheet manufacturing apparatus using an embodiment of the present invention cuts a glass strip.

[0055] Figure 12a This is a schematic front view showing a sixth example of how the second cutting device in a glass sheet manufacturing apparatus using an embodiment of the present invention cuts a glass strip.

[0056] Figure 12b This is a schematic front view showing a sixth example of how the second cutting device in a glass sheet manufacturing apparatus using an embodiment of the present invention cuts a glass strip.

[0057] Figure 13a This is a schematic front view illustrating a first variation of how a glass strip is cut by a second cutting device in a glass sheet manufacturing apparatus according to an embodiment of the present invention.

[0058] Figure 13b This is a schematic front view illustrating a first variation of how a glass strip is cut by a second cutting device in a glass sheet manufacturing apparatus according to an embodiment of the present invention.

[0059] Figure 14a This is a schematic front view illustrating a second variation of how a glass strip is cut by a second cutting device in a glass sheet manufacturing apparatus according to an embodiment of the present invention.

[0060] Figure 14b This is a schematic front view illustrating a second variation of how a glass strip is cut by a second cutting device in a glass sheet manufacturing apparatus according to an embodiment of the present invention. Detailed Implementation

[0061] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0062] Figure 1 This is a side view showing the overall structure of the glass plate manufacturing apparatus according to this embodiment. As shown in the figure, the glass plate manufacturing apparatus includes a glass strip G processing device 1, a first cutting device 2, and a second cutting device 3 as its main components.

[0063] The processing apparatus 1 includes: a forming zone 11, which continuously forms a glass strip G; a heat treatment zone 12, which heat-treats (anneales) the glass strip G; a cooling zone 13, which cools the glass strip G to near room temperature; and a conveying device 14, which is composed of roller pairs R arranged in multiple stages above and below the forming zone 11, the heat treatment zone 12 and the cooling zone 13 respectively.

[0064] The forming zone 11 and the heat treatment zone 12 are both furnaces surrounded by walls around the transport path of the glass strip G, and heating devices such as heaters for adjusting the temperature of the glass strip G are arranged in appropriate parts inside the furnace. On the other hand, the cooling zone 13 is not surrounded by walls around the transport path of the glass strip G but is open to the external environment at room temperature, and no heating devices such as heaters are provided.

[0065] A forming body 15, which forms a glass strip G from molten glass Gm using an overflow-pull method, is disposed within the internal space of the forming zone 11. Molten glass Gm supplied to the forming body 15 overflows from a groove (not shown) formed in the top 15a of the forming body 15. The overflowing molten glass Gm flows along the two wedge-shaped sides 15b of the forming body 15 and converges at the lower end. Thus, a plate-shaped glass strip G is continuously formed. This continuously formed glass strip G is fed downwards in a longitudinal (preferably vertical) orientation.

[0066] The interior space of the heat treatment zone 12 faces downwards and has a predetermined temperature gradient. The longitudinally oriented glass strip G is heat-treated (annealed) in such a manner that its temperature decreases as it moves downwards within the interior space of the heat treatment zone 12. This heat treatment reduces the internal strain of the glass strip G. The temperature gradient within the heat treatment zone 12 is adjusted, for example, by a heating device provided on the inner surface of the wall of the heat treatment zone 12.

[0067] Multiple roller pairs R constituting the conveying device 14 clamp the two ends of the glass strip G in a longitudinal orientation along its width from both sides of the back surface. The uppermost roller pair R located in the forming zone 11 is a cooling roller. It should be noted that, in the internal space of the heat treatment zone 12 or the like, roller pairs that do not clamp the side ends of the glass strip G may also be included among the multiple roller pairs R. That is, the opposing interval of the roller pairs R may be made larger than the thickness of the two ends of the glass strip G in the width direction, allowing the glass strip G to pass between the roller pairs R.

[0068] In this embodiment, the glass strip G manufactured by the processing apparatus 1 has a portion (hereinafter referred to as "ear") with a thickness greater than that of the central portion in the width direction at both ends due to shrinkage during the forming process.

[0069] The first cutting device 2 is configured to cut the longitudinally oriented glass strip G to a predetermined length along the width direction below the processing device 1, thereby sequentially cutting glass plates from the glass strip G. In subsequent processes, the glass plates have their ears removed to become raw glass plates (mother glass plates) for extracting one or more product glass plates. Here, the width direction is orthogonal to the length direction (transport direction) of the glass strip G, and in this embodiment, it is substantially aligned with the horizontal direction.

[0070] like Figure 1 as well as Figure 2As shown, the first cutting device 2 includes a scribing line forming device 21 and a breaking device 22.

[0071] The scribing line forming apparatus 21 is an apparatus for forming scribing lines S on the first main surface Ga of a glass strip G in a longitudinal orientation descending from the processing apparatus 1 at the scribing line forming position P1. In this embodiment, the scribing line forming apparatus 21 includes: a cutting wheel 23 that forms scribing lines S on the first main surface Ga of the glass strip G along the width direction of the glass strip G; and a support member 24 (e.g., a support rod, a support roller) that supports the second main surface (the surface opposite to the first main surface Ga) Gb of the glass strip G at a position corresponding to the cutting wheel 23. It should be noted that the scribing lines S can also be formed by laser irradiation or the like.

[0072] The breaking device 22 is a device that cuts a glass sheet by breaking the glass strip G along the scribe line S at a breaking position P2 located below the scribe line forming position P1. In this embodiment, the breaking device 22 includes: a breaking member 25 that abuts against the area where the scribe line S is formed from the second main surface Gb side; and a holding mechanism 26 that holds the lower region of the glass strip G at a position lower than the breaking position P2.

[0073] The breaking member 25 is composed of a plate-like body (platform) having a plane that contacts the entire area or a portion of the glass strip G in the width direction. The contact surface of the breaking member 25 may also be a curved surface that is bent in the width direction.

[0074] The holding mechanism 26 includes: a clamp 27 disposed at multiple locations in the vertical direction at both ends of the glass strip G in the width direction; and an arm 28 (see reference). Figure 2 The multiple clamps 27 are held at both ends in the width direction. It should be noted that the clamps 27 can also be changed to other holding methods such as holding the glass strip G by negative pressure adsorption.

[0075] like Figure 1 as well as Figure 2 As shown, the second cutting device 3 is positioned below the first cutting device 2, and when the first cutting device 2 is unusable due to maintenance or other reasons, it cuts the glass strip G that is continuously moving downwards while being formed in the forming area 11. It should be noted that in the following description, the second main surface Gb side of the glass strip G ( Figure 1 The arrow X side) is set as the front side, and the first main surface Ga side ( Figure 1 The arrow on the Y side is set as the back side.

[0076] The second cutting device 3 has a main frame 31 consisting of a structure provided behind the glass strip G. A pair of holding devices 32, a pair of cutting devices 33, and a stress-applying device 34 are sequentially mounted from top to bottom at the front end of the main frame 31. Furthermore, the second cutting device 3 includes a sensor 35 located behind the glass strip G.

[0077] A pair of retaining devices 32 have retaining members 36 respectively arranged corresponding to the two ends of the glass strip G in the width direction. These retaining members 36 are respectively rotatable around a rotation axis 37 (see reference). Figure 3 as well as Figure 4 (Rotation). Furthermore, these retaining members 36 can be configured to rotate as follows: Figure 3 As shown, the glass strip G is retreated to the outer side in the width direction (in Figure 5 (The state shown by the solid line) and as... Figure 4 The second principal surface Gb of the glass strip G is supported as shown in the figure (in Figure 5 (The state indicated by the single-dot dash).

[0078] A pair of cutting devices 33 each has a rotating blade 38 corresponding to the two ends of the glass strip G in the width direction. These rotating blades 38 are respectively movable in the front-back direction (towards the front and upwards). Figure 2 as well as Figure 5 Moreover, these rotating blades 38 can each be transformed into, for example... Figure 3 As shown, the glass strip G is retreated to the rear (in Figure 5 (The state shown by the solid line) and as... Figure 4 As shown, it is in contact with both ends of the glass strip G in the width direction (in Figure 5 (The state is shown by the single-dot dash). Furthermore, these rotating blades 38 remain at the same height and can move and operate independently. When the rotating blades 38 contact the glass strip G, they can perform processes such as etching lines at the width-direction end of the glass strip G and cutting off the width-direction end of the glass strip G.

[0079] The stress-applying device 34 has a pressing member 41 (see reference) mounted on the front end of a pair of swing arms 40 capable of swinging about a support shaft 39. Figure 1 as well as Figure 2 The pressing member 41 is a roller-shaped member extending in the width direction and is longer than the width direction length of the glass strip G. Furthermore, the pressing member 41 can be varied as follows: Figure 3 As shown, the glass strip G is retreated to the rear (in Figure 5 (The state shown by the solid line) and as... Figure 4 The glass strip G is pressed as shown in the diagram (in...) Figure 5 (The state indicated by the single-dot dash).

[0080] Multiple sensors 35 are provided corresponding to various locations along the width of the glass strip G. In this embodiment, a total of three sensors 35 are provided at locations corresponding to both ends of the glass strip G along its width and at a location corresponding to the center of the width (see reference). Figure 2 These sensors 35 are fixed to the front end of the main frame 31 in a straight line along the width direction and held in a constant position. Laser sensors, ultrasonic sensors, thermal sensors, etc., are used as sensors 35.

[0081] The basic cutting process based on the second cutting device 3 is carried out as follows. First, as in Figure 5 As shown by the solid line, during the continuous downward movement of the glass strip G while it is being formed, the retaining member 36 rotates. Thus, the retaining member 36, as shown by the dashed line in the figure, can hold the second principal surface Gb of the glass strip G. In this state, the pressing member 41 swings forward. Thus, the pressing member 41 presses the glass strip G, as shown by the dashed line in the figure, imparting bending stress to the area GX of the glass strip G to be cut, i.e., the peripheral area Gx of the cutting position P3 where the rotating blade 38 cuts. At this time, the retaining member 36 holds the second principal surface Gb of the glass strip G above the cutting position P3 and prevents the glass strip G from displacing forward. In this state, the rotating blade 38 moves forward. Thus, the rotating blade 38, as shown by the dashed line in the figure, contacts the first principal surface Ga of the glass strip G at the cutting position P3 and etches a marking line (initial crack) onto the glass strip G. The initial crack is simultaneously etched by a pair of rotating blades 38 at both ends of the glass strip G in the width direction. The initial cracks can be incised at locations including or excluding the lugs on the glass strip G. These initial cracks propagate along the width of the glass strip G, thus cutting it. The cut glass, now discarded glass Gy, falls downwards and is collected in the recycling area 42. Subsequent cutting processes are then performed on the glass strip G in the same manner. Three sensors 35 inspect the cutting status of the glass strip G after the initial cutting process for a predetermined period until the subsequent cutting process is performed.

[0082] Next, a glass plate manufacturing method using a glass plate manufacturing apparatus having the structure described above will be explained.

[0083] The glass plate manufacturing method of this embodiment includes a forming process, a handling process, a first cutting process, and a second cutting process.

[0084] The forming process is the process of forming glass strip G in forming zone 11.

[0085] The transport process involves using the rollers of the transport device 14 to transport the formed glass ribbon G to R. It should be noted that the transport process includes both heat treatment and cooling processes.

[0086] The heat treatment process is a process in which the glass strip G, which has undergone the forming process, is heat-treated in the heat treatment zone 12 at the same time as it is being transported.

[0087] The cooling process is a process in the cooling zone 13 where the glass strip G, which has undergone the heat treatment process, is cooled while being transported.

[0088] The first cutting process is a process in which the glass strip G, which has undergone the cooling process, is cut along the width direction using the first cutting device 2 to obtain a glass plate.

[0089] In detail, such as Figure 1 as well as Figure 2 As shown, in the first cutting process, firstly, the cutter wheel 23 and the support member 24, while moving in tandem with the downwardly moving glass strip G, form a scribe line S over the entire area or a portion of the width of the glass strip G. In this embodiment, the scribe line S is also formed on the relatively thick ear portion. Next, after the multiple chucks 27 hold the glass strip G, the arm 28 moves the multiple chucks 27 in tandem with the glass strip G. At this time, the breaking member 25 also moves in tandem with the glass strip G. During these movements, the arm 28 performs an action to bend the glass strip G with the breaking member 25 as a fulcrum. Figure 1 (The action is shown in direction B). This imparts bending stress to the scribe line S and its vicinity, causing the glass strip G to break along the scribe line S in the width direction. The result of this breakage is that a glass plate is cut from the glass strip G.

[0090] The second cutting process is the process of cutting the glass strip G using the second cutting device 3 without using the first cutting device 2.

[0091] For example, in the second cutting process, after the glass strip G has undergone the previous cutting process, the cutting status of the glass strip G is checked by the sensor 35, and the subsequent cutting process is performed on the glass strip G based on the inspection result of the sensor 35.

[0092] In this embodiment, as already described, the three sensors 35 are held in a constant position. Therefore, as Figure 6 As shown, the inspection area E of the three sensors 35 is separated downward by a predetermined length L1 from the cutting position P3 where the glass strip G is cut by the rotating blade 38. Therefore, in this embodiment, the three sensors 35 inspect the cutting state of the glass strip G as it approaches and passes through the inspection area E after being cut at the cutting position P3.

[0093] Specifically, three sensors 35 check whether the glass strip G has a cut-off portion (details to follow) after the glass strip G has undergone the prior cutting process. The cut-off portion is the protrusion of the glass strip G that protrudes downward from the cut position P3 when the glass strip G has undergone the prior cutting process.

[0094] In this embodiment, a first inspection result based on three sensors 35 is obtained during a first period, which is predetermined as the length of the glass strip G that has traveled since the previous cutting process reaches a predetermined length L1. If necessary, a second inspection result based on the three sensors 35 is obtained during a second period following the first period. Furthermore, the first and second inspection results can be obtained continuously from the moment the previous cutting process occurred, or they can be obtained at predetermined time intervals. Here, the first and second inspection results based on the three sensors 35 can be obtained by an operator or an automated control mechanism such as a personal computer. An example of a specific method for performing this operation is shown below.

[0095] Figure 7a as well as Figure 7b The first example of the above specific method is shown. In this first example, as... Figure 7a As shown, when the glass strip G has undergone the prior cutting process, the glass strip G is cut at the cutting position P3 in a straight line along the width direction. This means that the glass strip G is cut normally. If the glass strip G moves downwards, in the first period, as in... Figure 7b As shown by the solid line, all three sensors 35 failed to detect the glass band G. Having obtained this information, a second period is initiated until all three sensors 35 detect the glass band G. Furthermore, in the second period, if all three sensors 35 detect the glass band G, for example, as in... Figure 7b As shown by the dashed line, for example, when the glass strip G reaches a predetermined position P4, it is cut across its entire width at the cutting position P3 as part of the subsequent cutting process. This predetermined position P4 is the position where a predetermined length L2, longer than L1, is separated downwards from the cutting position P3. Thus, the glass strip G is cut to the predetermined length L2. This subsequent cutting process is performed by forming an initial crack using a pair of rotating blades 38 while the holding member 36 and the pressing member 41 apply bending stress to the area Gx of the glass strip G to be cut. It should be noted that when the glass strip G is cut normally, all three sensors 35 detect the glass strip G at the point of transition from the first to the second stage.

[0096] Figure 8A second example of the above-described method is shown. In this second example, when the glass strip G has undergone the previous cutting process, the glass strip G is not cut at the cutting position P3. Therefore, when the glass strip G moves downward, in the first period, as shown by the solid line in the figure, all three sensors 35 detect the glass strip G. Upon obtaining this information, the glass strip G is immediately cut across its entire width as a subsequent cutting process. It should be noted that if the glass strip G has not reached the set position P4 at the time this information is obtained, the subsequent cutting process can also be performed on the glass strip G when it reaches the set position P4, as shown by the dashed line in the figure. The subsequent cutting process in this second example is also the same as in the first example described, using the holding member 36, the pressing member 41, and a pair of rotating blades 38.

[0097] Figure 9a as well as Figure 9b A third example of the specific method described above is shown. In this third example, as... Figure 9a As shown, after the glass strip G has undergone the prior cutting process, a remaining portion Gc protruding downwards from the cutting position P3 remains at more than half (more than half on the left side) in the width direction of the glass strip G. If the glass strip G moves downwards, in the first period, as in... Figure 9b As shown by the solid line, the two sensors 35 at the left end and the center in the width direction detect the glass strip G. Having obtained this information, a second period is initiated until the sensor 35 at the right end in the width direction detects the glass strip G. Furthermore, in the second period... Figure 9b As shown by the dashed line, when the sensor 35 at the right end in the width direction detects the glass strip G, this information is obtained, and the glass strip G is cut at the cutting position P3 along its entire width length as part of the subsequent cutting process. In this case, the subsequent cutting process can also be performed on the glass strip G immediately when the sensor 35 at the right end in the width direction detects the glass strip G. For this purpose, it is necessary to set the structure so that the pressing member 41 presses the glass strip G at a position higher than the inspection area E of the three sensors 35. In addition, when the subsequent cutting process can be performed, assuming that the lowermost end Gcx of the cut portion Gc of the glass strip G has not reached the set position P4 as shown in the figure, the subsequent cutting process can also be performed on the glass strip G when it reaches the set position P4. The subsequent cutting process in this third example is also the same as in the first example described above, using the holding member 36, the pressing member 41, and a pair of rotating blades 38.

[0098] Figure 10a as well as Figure 10b A fourth example of the above specific method is shown. This fourth example differs from the third example in that... Figure 10aAs shown, at the moment when the glass strip G has undergone the prior cutting process, remnants Gc protruding downwards from the cutting position P3 remain at both ends of the glass strip G in the width direction. Therefore, when the glass strip G moves downwards, in the first period, as in Figure 10b As shown by the solid line, the two sensors 35 at both ends of the width direction detect the glass strip G. After obtaining this information, the process waits in the second period until the sensor 35 at the center of the width direction detects the glass strip G. Then, the subsequent cutting process of the glass strip G is performed in the same manner as in the third example described above.

[0099] Figure 11a as well as Figure 11b The fifth example of the above specific method is shown. In this fifth example, as... Figure 11a As shown, after the glass strip G has undergone the prior cutting process, only one end (left end) of the glass strip G in the width direction retains a cut remnant Gc protruding downward from the cutting position P3. If the glass strip G moves downward, in the first period, as in... Figure 11b As shown by the solid line, only the sensor 35 at the left end in the width direction detects the glass strip G. Having obtained this information, in the second period, the system waits until a total of two sensors 35 at the center and right end in the width direction detect the glass strip G, or without waiting, and then, as part of the subsequent cutting process, uses the rotating blade 38 to cut only the remaining portion Gc along the width direction. In the case of cutting only the remaining portion Gc, the rotating blade 38 needs to be configured to move vertically, and the rotating blade 38 needs to be pre-moved to a position where only the remaining portion Gc can be cut. Therefore, in this case, the holding member 36 and the pressing member 41 may not need to be activated. Alternatively, in this case, it is also possible that, at the moment when the subsequent cutting process can be performed, assuming... Figure 11b If the lowest end Gcx of the cut portion Gc of the glass strip G shown by the single-dotted line has not reached the set position P4, only the cut portion Gc is cut off when it reaches the set position P4. Alternatively, if the two sensors 35 at the center and right end of the width direction in the second period do not detect the glass strip G within a specified period, subsequent cutting processing is performed on the glass strip G.

[0100] Figure 12a as well as Figure 12b A sixth example of the specific method described above is shown. In this sixth example, as... Figure 12a As shown, when the glass strip G has undergone a prior cutting process, a remnant Gc protrudes downwards from the cutting position P3, and a notch Gd is created that is recessed upwards from the cutting position P3. If the glass strip G moves downwards, in the first period, as in... Figure 12bAs shown by the solid line, a total of two sensors 35 detected the glass strip G. Having obtained this information, it is also possible to wait in the second period until only one sensor 35 detects the glass strip G, and then perform the subsequent cutting process on the glass strip G in the same manner as in the third example described above. However, it is also possible to proceed as follows: That is, in the second period, if one sensor 35 fails to detect the glass strip G within a predetermined time, after the predetermined time has elapsed, the glass strip G is subjected to the subsequent cutting process in the same manner as in the third example described above. This predetermined time is, for example, set based on the moment when the glass strip G has undergone a previous cutting process. Alternatively, in this case, it is also possible to perform the subsequent cutting process on the glass strip G in the same manner as in the third example described above when the lowest end Gcx of the remaining cut portion Gc of the glass strip G reaches the set position P4.

[0101] The above example illustrates the use of three sensors 35 to cut the glass strip G, but it is also possible to cut the glass strip G using only two sensors 35. In this case, the ears at both ends of the glass strip G in the width direction are thicker than its central portion, so a long, narrow cut remnant is easily left around the ears, especially at the bottom. Therefore, it is also possible to omit the sensor 35 at the central portion of the width direction of the three sensors 35 described above and use a total of two sensors 35 at both ends of the width direction. An example of this specific method is shown below (hereinafter referred to as a variation).

[0102] Figure 13a as well as Figure 13b A first variation is shown. In this first variation, as... Figure 13a As shown, after the glass strip G has undergone the previous cutting process, a narrow cut remnant Gc protruding downwards from the cutting position P3 remains at one end (left end) of the glass strip G in the width direction. If the glass strip G moves downwards, in the first period, as in... Figure 13b As shown by the solid line, sensor 35 at the left end in the width direction detects the glass strip G. Having obtained this information, the system either waits until sensor 35 at the right end in the width direction detects the glass strip G, or it does not wait, in order to... Figure 11a as well as Figure 11b The same principle applies to the fifth example already described, where the rotating blade 38 is used to cut off only the remaining portion Gc along the width direction as a subsequent cutting process. Alternatively, in this case, it is also possible that, at the moment when the subsequent cutting process can be performed, assuming as in... Figure 13b If the lowest end Gcx of the cut portion Gc of the glass strip G shown by the single-dotted line has not reached the set position P4, only the cut portion Gc will be cut off when it reaches the set position P4.

[0103] Figure 14a as well as Figure 14b A second variation is shown. In this second variation, as... Figure 14a As shown, after the glass strip G has undergone the previous cutting process, narrow cut portions Gc protruding downwards from the cutting position P3 remain at both ends of the glass strip G in the width direction. If the glass strip G moves downwards, in the first period, as in... Figure 14b As shown by the solid line, sensors 35 at both ends in the width direction detect the glass strip G. Having obtained this information, after a specified time, [the sensor]... Figure 9a as well as Figure 9b The same procedure is used to perform subsequent cutting of the glass strip G as in the third example already described. The specified time here is set, for example, based on the moment when the glass strip G has undergone a previous cutting process. Alternatively, in this case, it could be performed at the moment when the subsequent cutting process can be carried out, assuming, as in... Figure 14b If the lowest end Gcx of the cut portion Gc of the glass strip G shown by the single-dotted line has not reached the set position P4, only the cut portion Gc will be cut off when it reaches the set position P4.

[0104] According to the glass plate manufacturing apparatus and manufacturing method of the present invention having the above-described structure, the following effects are obtained.

[0105] In the above embodiment, during the first cutting process, the cutter wheel 23, support member 24, arm 28, multiple clamps 27, and breaking member 25 move along with the glass strip G. Therefore, the structure of the first cutting device 2 is complex, but it can cut the glass strip G with good quality and accuracy. In contrast, during the second cutting process, the components of the second cutting device 3 do not move along with the glass strip G. Therefore, the structure of the second cutting device 3 is extremely simple compared to the first cutting device 2, and thus, in the second cutting process, it is easy to produce poor cutting or failure to cut. Therefore, in the second cutting process, various countermeasures as described above are taken to avoid such undesirable situations. As a result, appropriate cutting operations can be performed in both the first and second cutting processes.

[0106] In the above embodiment, when the second cutting process is performed instead of the first cutting process, the state of the lower end of the glass strip G after the previous cutting process is checked by the sensor 35, thus enabling appropriate handling of issues such as poor cutting or inability to cut. Specifically, if the lower end of the glass strip G improperly lengthens downwards due to poor cutting or inability to cut caused by the previous cutting process, the sensor 35 quickly and accurately detects this and reflects the detection result to the subsequent cutting process. Therefore, in the subsequent cutting process, an appropriate cut can be performed so that the lower end of the glass strip G does not become an obstacle. This avoids undesirable situations such as the lower end of the glass strip G getting caught on the components of the second cutting device 3 or colliding with the end of the glass strip G's movement path during its continuous downward movement. That is, if the lower end of the glass strip G is improperly lengthened downwards, and the pressing member 41 of the second cutting device 3 has not returned to the retracted position, the lower end of the glass strip G may get caught on the swing arm 40 that supports the pressing member 41. Furthermore, if the lower end of the glass strip G is of improper length at the bottom, it is possible for the lower end of the glass strip G to collide with the recycling area 42 where no glass Gy is to be recycled. In the above embodiment, these situations can be prevented. As a result, longitudinal breakage of the glass strip G can be prevented.

[0107] In the second cutting step of the above embodiment, after the glass strip G has undergone the previous cutting process, a check is performed to see if there is a cut-off portion Gc in the glass strip G. Therefore, even if there is a cut-off portion Gc in the glass strip G, the sensor 35 detects the cut-off portion Gc and reflects the detection result to the subsequent cutting process, thus effectively preventing longitudinal cracking of the glass strip G caused by the presence of the cut-off portion Gc.

[0108] In this case, the aforementioned residual portion is the protrusion of the glass strip G that extends downward from the cutting position P3 after the glass strip has undergone a previous cutting process. Therefore, if the glass strip G has undergone normal cutting at the cutting position P3, no protrusion extending downward from the cutting position P3 will form on the glass strip G. Conversely, in cases of poor cutting or inability to cut, a protrusion extending downward from the cutting position P3, i.e., a residual portion Gc, will remain on the glass strip G. Therefore, by checking the presence or absence of the residual portion Gc using the sensor 35, it is possible to accurately determine whether normal cutting has been performed, and consequently, to accurately determine whether replacement of components of the second cutting device 3 is necessary.

[0109] In the second cutting process of the above embodiment, multiple (three or two) sensors 35 are provided corresponding to multiple locations in the width direction of the glass strip G. Therefore, the cutting status can be checked at multiple locations in the width direction of the glass strip G using multiple sensors 35, resulting in detailed and highly accurate inspection by the sensors 35.

[0110] In the second cutting process of the above embodiment, the subsequent cutting process is performed differently depending on the different inspection results of the multiple sensors 35. Therefore, the subsequent cutting process can be performed differently depending on the different cutting states inspected by the multiple sensors 35, and the cutting states of each part can be taken into account to perform the subsequent cutting process appropriately.

[0111] In the second cutting process of the above embodiment, multiple sensors 35 have inspection areas at positions where a predetermined length L1 is separated downward from the cutting position P3. Furthermore, a first inspection result based on the multiple sensors 35 is obtained during a first period, predetermined when the moving length of the glass strip G from the previous cutting process reaches the predetermined length L1. Additionally, a second inspection result based on the multiple sensors 35 is obtained in a second period following the first period, as needed. In this way, by comparing with the case where the glass strip G has undergone normal cutting at the cutting position P3, results obtained from the multiple sensors 35 inspecting the cutting state of each portion of the glass strip G can be obtained. Specifically, obtaining the first detection result in the first period allows it to determine whether the lower end of the glass strip G is improperly lengthened downwards. Furthermore, obtaining the second detection result in the second period allows it to determine the appropriate time for performing subsequent cutting processes on the glass strip G. Therefore, the inspection performed by the multiple sensors 35 can be performed more meticulously, and their inspection results can be effectively utilized.

[0112] In the second cutting step of the above embodiment, when the glass strip G is cut across its entire width as a subsequent cutting process, bending stress is applied to the area Gx of the glass strip G to be cut. Therefore, the bending stress can be effectively utilized to cut the glass strip G across its entire width, and the subsequent cutting process can be performed smoothly and reliably.

[0113] In the second cutting step of the above embodiment, when only a portion of the glass strip G in the width direction is cut as a subsequent cutting process, bending stress is not applied to the area Gx of the glass strip G to be cut. Therefore, the effort of applying bending stress can be eliminated, and the subsequent cutting process can be performed earlier and more easily.

[0114] The glass plate manufacturing apparatus and manufacturing method according to the embodiments of the present invention have been described above. However, the embodiments of the present invention are not limited thereto, and various modifications can be made without departing from the spirit of the present invention.

[0115] In the above embodiment, the glass strip G was formed by the overflow pull-down method, but it can also be formed by other pull-down methods such as the slit pull-down method or the re-pull method.

[0116] In the above embodiment, in the first cutting process, the glass strip G is cut by breaking along the scribe line S, but other methods such as laser cutting or laser melting can also be used to cut the glass strip G.

[0117] In the above embodiment, the second cutting device 3 is arranged below the first cutting device 2, but the two devices 2 and 3 can also be arranged side by side in a position that overlaps in the vertical direction. In such a case, the main frame 31 of the second cutting device 3 is kept in a constant position, and when using the first cutting device 2, the holding member 36, the rotating blade 38, and the pressing member 41 are pre-positioned to avoid obstructing the operation of the first cutting device 2.

[0118] In the above embodiment, a rotating blade 38 is used to cut the glass strip G, but it is not limited to this as long as it has a cutting blade.

[0119] In the above embodiments, two or three sensors 35 are arranged along the width direction, but four or more sensors 35 may also be arranged along the width direction.

[0120] In the above embodiments, there is a prior cutting process, but it could also be the initial stage of forming the glass strip G and before the glass strip G has been cut. In this case, the starting point of the first period could be set, for example, as the moment when the front end of the glass strip G reaches the position of the holding member 36 of the second cutting device 3 in the same height direction.

[0121] Explanation of reference numerals in the attached figures

[0122] 1. Glass ribbon processing device

[0123] 2 First cutting device

[0124] 3 Second cutting device

[0125] 11 Forming Zone

[0126] 31 Main Framework

[0127] 32 Holding device

[0128] 34 Stress-Applying Device

[0129] 35 sensors

[0130] 36 retaining components

[0131] 38 rotating blades

[0132] 40 swing arm

[0133] 41 Pressing component

[0134] Inspection area of ​​E sensor

[0135] G glass ribbon

[0136] Gc cut-off part

[0137] Gm molten glass

[0138] The area where the Gx glass strip should be cut

[0139] P3 cut-off position.

Claims

1. A method for manufacturing a glass plate, comprising: The first cutting process involves cutting the glass strip, which moves continuously downwards while being formed in the forming zone, along the width direction to cut out a glass plate. And a second cutting process, in which the glass ribbon is cut using a device with a different structure than the device used in the first cutting process, when the first cutting process is not performed. The glass plate manufacturing method is characterized by the following: In the second cutting process, the state of the glass strip is checked using a sensor, and the glass strip is cut based on the sensor's inspection result. The sensor is provided in multiple locations corresponding to various positions along the width of the glass strip. Multiple sensors inspect for downward-protruding protrusions in a portion of the width of the glass strip. Based on the different inspection results of the multiple sensors, the cutting process is divided into a process that cuts the glass strip across its entire width and a process that cuts only the downwardly protruding portion of the glass strip in its width.

2. The glass plate manufacturing method according to claim 1, wherein, If the inspection result indicates the presence of the protrusion, a process is performed to cut off only the protrusion as part of the cutting process.

3. The glass plate manufacturing method according to claim 1, wherein, The multiple sensors have an inspection area at a position where a predetermined length is separated downward from the cutting position where the cutting process is performed in the second cutting step, and obtain a first inspection result based on the multiple sensors during a first period until the glass strip reaches the inspection area.

4. The glass plate manufacturing method according to claim 3, wherein, If none of the multiple sensors detect the glass strip in the first period, a second inspection result based on the multiple sensors is obtained in the second period following the first period. If all of the multiple sensors detect the glass strip in the second period, the glass strip is cut off along its entire width as part of the cutting process.

5. The glass plate manufacturing method according to claim 3, wherein, If all of the sensors detect the glass strip during the first period, the glass strip is cut along its entire width as part of the cutting process.

6. The glass plate manufacturing method according to claim 3, wherein, If, during the first period, two or more of the multiple sensors detect the glass strip and one or more sensors fail to detect it, a second inspection result based on the sensors is obtained in the second period following the first period. During the second period, the process waits until one or more of the remaining sensors detect the glass strip. If, during the second period, one or more of the remaining sensors detect the glass strip, the glass strip is cut along its entire width as part of the cutting process.

7. The method for manufacturing a glass plate according to any one of claims 4 to 6, wherein, When the glass strip is cut across its entire width as part of the cutting process, bending stress is applied to the area of ​​the glass strip that should be cut.

8. The glass plate manufacturing method according to claim 3, wherein, If, during the first period, one of the multiple sensors detects the glass strip and one or more remaining sensors fail to detect the glass strip, the cutting process involves cutting only a portion of the glass strip in the width direction corresponding to the one sensor.

9. The glass plate manufacturing method according to claim 8, wherein, The portion of the glass strip in the width direction is one end of the glass strip in the width direction.

10. The method for manufacturing a glass plate according to claim 8 or 9, wherein, When cutting only a portion of the glass strip in the width direction as the cutting process, no bending stress is applied to the area of ​​the glass strip that should be cut.

11. A glass sheet manufacturing apparatus, comprising: a first cutting device that cuts a glass strip that moves continuously downward in a forming zone along its width direction to produce a glass sheet; and a second cutting device that, when not using the first cutting device, has a different structure from the first cutting device and cuts the glass strip. The glass plate manufacturing apparatus is characterized in that... The second cutting device is configured to use a sensor to check the state of the glass strip and perform the cutting process of the glass strip based on the check result of the sensor. The sensor is provided in multiple locations corresponding to various positions along the width of the glass strip. Multiple sensors inspect for downward-protruding protrusions in a portion of the width of the glass strip. The second cutting device is configured to, based on the different inspection results of the plurality of sensors, divide the cutting process into a process that cuts the glass strip over its entire width and a process that cuts only the downwardly protruding portion of the glass strip in its width.

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