Method for manufacturing a glass sheet

Abstract

In a manufacturing method of a glass sheet, a carrying process in which a glass sheet (G) and a protective sheet (S) are sequentially taken out from a glass sheet laminate (2) loaded on a tray (1) and carried, and a detection process in which it is detected whether or not a crack is generated in the glass sheet (G) based on the weights of the glass sheet (G) and the protective sheet (S) measured when the glass sheet (G) and the protective sheet (S) are carried in the carrying process.

Description

Technical Field

[0001] This invention relates to a method for manufacturing glass plates, including a handling process of removing and transporting glass plates from a glass plate laminate. Background Technology

[0002] In the field of glass manufacturing, the process involves transporting laminated glass sheets, loaded onto pallets, in bundled form to other factories or transferring them within the same factory. Typically, glass laminates are constructed by alternating layers of glass sheets and protective sheets.

[0003] After the bundle is unbundled following the completion of conveying and transfer, a transport process is performed in which the glass plates (or glass plates and protective sheets) are sequentially removed from the glass plate stack and transported to the next process (for example, see Patent Documents 1 and 2). The glass plates arriving at the next process undergo end-face processing, etching, etc.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-99330

[0007] Patent Document 2: Japanese Patent Application Publication No. 2019-151434 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] During the bundling, conveying, and transfer of glass plate stacks, breakage can easily occur due to swaying and vibration. When breakage occurs, it hinders end-face processing and etching treatments performed on the glass plates after unbundling.

[0010] To address this problem, the inventors attempted to detect breakage of glass plates as they were sequentially removed and transported from a glass plate stack using cameras, sensors, and the like. However, they concluded that detecting breakage across the entire surface of the glass plate using this method was not easy and that accurate detection was difficult.

[0011] Based on the above viewpoints, the objective of this invention is to easily and accurately detect whether any cracks have occurred on the entire surface of a glass plate during a handling process in which glass plates are sequentially removed from and transported from a glass plate stack loaded on a tray.

[0012] Solution for solving the problem

[0013] (1) The present invention, made to solve the above-mentioned problem, is a method for manufacturing a glass plate, including a transport step of sequentially taking out and transporting glass plates from a glass plate stack loaded on a tray, wherein the glass plate manufacturing method is characterized in that, based on the weight of the glass plate measured during the transport step, it is detected whether the glass plate has cracked.

[0014] If a glass plate breaks, the broken portion will fall during the handling process. Therefore, the weight will be lighter than if the glass plate were unbroken. Thus, by measuring the weight of the glass plate during handling, it is possible to easily and accurately detect whether a breakage has occurred on the entire surface of the glass plate.

[0015] (2) In the structure of (1) above, it is also possible to compare the weight of the glass plate measured by the first glass plate being transported with the weight of the glass plate measured by the second glass plate being transported after the first glass plate when detecting whether the glass plate has cracked.

[0016] In this way, even if there is a weight difference between the glass plates taken out in the early stage of the glass plate stack and the glass plates taken out in the later stage, which is due to the deviation of the manufacturing conditions of the glass plates, and such a weight difference is unacceptable, the cracking of the glass plates can be detected without being affected.

[0017] (3) In the structure of (2) above, it is also possible to visually inspect the glass plate to check whether the glass plate has cracked, and compare the weight of the glass plate that has no cracked inspection result with the weight of the glass plate that was transported after the glass plate.

[0018] In this way, after visually confirming that the glass plate has not broken, the weight of the glass plate is compared with the weight of the glass plate that is transported after it, thus preventing false detection of breakage.

[0019] (4) In any of the structures (1) to (3) above, the glass plate may be transported in a suspended support state during the transport process, and the weight of the glass plate may be measured by a weight measuring mechanism provided in the suspension part for suspending the glass plate.

[0020] In this way, the weight of the glass plate being transported by suspension support can be measured efficiently and quickly using a weight measuring mechanism.

[0021] (5) In any of the structures (1) to (4) above, the glass plate may be transported in a direction orthogonal to the main surface of the glass plate.

[0022] In this way, a series of operations can be carried out smoothly, including taking the glass plates out of the glass plate stack and transporting them to the next process.

[0023] (6) In any of the structures (1) to (5) above, the glass plate in the transport process may have an ascending path that rises in the transport direction and a descending path that falls in the transport direction after passing through the ascending path. Based on the weight of the glass plate measured in the descending path, it is detected whether the glass plate has cracked.

[0024] In this way, the weight change of the glass plate during the descent path after sufficient time has passed since it was removed from the glass plate stack is smaller than the weight change of the glass plate during the ascent path before sufficient time has passed. That is, the weight of the glass plate becomes stable during the descent path compared to the weight of it during the ascent path. Therefore, by measuring the weight of the glass plate in its stable state during the descent path, it is possible to detect glass plate breakage more accurately.

[0025] (7) In the structure of (6) above, it is also possible to detect whether the glass plate has cracked based on the weight of the glass plate measured at the front end of the transport direction of the descent path.

[0026] In this way, the weight of the glass plate is measured at the front end of the transport direction of the descent path, which is the most stable state during the descent, thus enabling more accurate detection of glass plate breakage.

[0027] (8) In any of the structures (1) to (7) above, the glass plate stack can also be formed by alternating arrangement of the glass plate and the protective sheet. In the handling process, the protective sheet is taken out and handled sequentially from the glass plate stack, overlapping the glass plate, and the weight of the glass plate plus the weight of the protective sheet is measured.

[0028] In this way, with a protective sheet superimposed on the glass plate, even if the protective sheet becomes an obstacle and makes it difficult to detect glass plate breakage by the camera, sensor, etc., the breakage can still be detected without being hindered by the protective sheet. Furthermore, when the glass plate breaks, the broken portion falls off, reducing the weight of the glass plate. Conversely, even if the protective sheet is damaged, the damaged portion usually does not fall off, and even if it does, the weight of the fallen portion is minimal, so the weight of the protective sheet can be considered unchanged. Therefore, even if the weight of the glass plate plus the weight of the protective sheet is measured, the breakage of the glass plate can be detected without being affected by the weight of the protective sheet.

[0029] Invention Effects

[0030] According to the present invention, it is possible to easily and accurately detect whether cracks have occurred on the entire surface of a glass plate during a handling process in which glass plates are sequentially removed and transported from a glass plate stack loaded on a tray. Attached Figure Description

[0031] Figure 1 This is a side view showing the outline structure of a manufacturing apparatus for a method of manufacturing a glass plate for implementing embodiments of the present invention.

[0032] Figure 2 This is a side view of the separation process in a method for manufacturing a glass plate according to an embodiment of the present invention.

[0033] Figure 3 This is a side view illustrating the handling process, weight measurement process, and breakage detection process in the glass plate manufacturing method of an embodiment of the present invention.

[0034] Figure 4 This is a side view illustrating the handover process in the glass plate manufacturing method of an embodiment of the present invention.

[0035] Figure 5 This is a side view illustrating the posture conversion process and the delivery process in the glass plate manufacturing method of an embodiment of the present invention.

[0036] Figure 6 This is a perspective view showing the detailed structure of a glass plate manufacturing method according to an embodiment of the present invention.

[0037] Figure 7 This is a top view illustrating, in a time sequence, the transport method of the glass plate and the protective sheet in the glass plate manufacturing method of an embodiment of the present invention. Detailed Implementation

[0038] Hereinafter, a method for manufacturing a glass plate according to an embodiment of the present invention will be described with reference to the accompanying drawings. It should be noted that... Figures 1-5 In the diagram, the direction of arrow A is the front side, and the direction of arrow B is the back side.

[0039] Figure 1This is a side view showing the general structure of a manufacturing apparatus for implementing the glass plate manufacturing method of this embodiment. As shown in the figure, the manufacturing apparatus includes: a transport unit 3, which removes and transports glass plates G one by one from the glass plate stack 2 loaded on a tray 1; and a posture conversion table 4, which transfers the glass plates G after transport. In this embodiment, the transport unit 3 removes and transports one glass plate G and one protective sheet S as a set. In addition, the manufacturing apparatus includes an adsorption pad 5 used when removing a set of glass plates G and protective sheets S from the glass plate stack 2.

[0040] The glass plate laminate 2 is obtained by alternating rectangular glass plates G and rectangular protective sheets S in a longitudinal orientation. The upper end of the protective sheet S preferably extends upward from the upper end of the glass plate G. Furthermore, the two ends of the protective sheet S in the width direction (the direction orthogonal to the paper plane) preferably extend from the two ends of the glass plate G in the width direction. It should be noted that... Figures 1-5 For ease of recording, the upper end of the protective sheet S does not extend upward from the upper end of the glass plate G, and the two ends of the protective sheet S in the width direction do not extend from the two ends of the glass plate G in the width direction.

[0041] The tray 1 includes: a base portion 1a that supports the glass plate stack 2 from below; and a backrest 1b that extends upward from the rear of the base portion 1a and supports the glass plate stack 2 from the rear. The base portion 1a has a lower end support surface 1aa that supports the lower end of the glass plate stack 2. The backrest 1b has a rear end support surface 1ba that supports the rear end (back side) of the glass plate stack 2. The lower end support surface 1aa is an inclined surface that slopes upward towards the front. The rear end support surface 1ba is an inclined surface that slopes backward towards the top. Therefore, the glass plates G and protective sheets S of the glass plate stack 2 loaded on the tray 1 are in a rearward inclined posture with their upper ends located further back than their lower ends.

[0042] The glass plate G and the protective sheet S are preferably tilted at an angle of 45° to 88° relative to the horizontal plane when loaded on the tray 1, and more preferably at an angle of 75° to 88° relative to the horizontal plane. In this embodiment, the glass plate G has a thickness of 500 μm or less (the lower limit is, for example, 10 μm) and is flexible. It should be noted that this is not a limitation; the thickness of the glass plate G may exceed 300 μm but be less than 3200 μm. The size of the glass plate G is preferably 900 to 4000 mm on one side, and more preferably 1800 to 3500 mm on one side. In this embodiment, the glass plate G is formed by an overflow pull-down method, but it can also be formed by other methods such as slit pull-down, re-pull-down, or float glass.

[0043] In this embodiment, the protective sheet S is formed of a foamed resin sheet, but it can also be formed of a backing paper, a non-foamed resin sheet, or the like. The protective sheet S can also be made of a material that prevents air from passing through in a direction perpendicular to its surface, but in this embodiment, it is made of a material that allows air to pass through. Therefore, in this embodiment, with the protective sheet S overlapping the front side of the glass plate G, the protective sheet S and the glass plate G can be removed as a set from the front using the suction pad 5.

[0044] The transport unit 3 is able to move in the front-back direction by engaging with a track (not shown) extending in the front-back direction at its upper end. In this embodiment, the transport unit 3 moves forward, thereby transporting a set of glass plates G and protective sheets S from the periphery of the placement area of ​​the tray 1 to the periphery of the setting area of ​​the attitude conversion table 4. At this time, the set of glass plates G and protective sheets S are transported in a direction orthogonal to the main surface Ga of the glass plate G while being suspended and supported by the transport unit 3 in a longitudinal posture. After the transport is completed and the set of glass plates G and protective sheets S are handed over to the attitude conversion table 4, the transport unit 3 moves backward and returns to the periphery of the placement area of ​​the tray 1.

[0045] The conveying unit 3 includes: a holding structure 6 that holds the upper ends of a set of glass plates G and protective sheets S; and a hanging member 7 whose upper end engages with a track extending in the front-rear direction. A force sensor 8, serving as a weight measuring mechanism, is installed between the holding structure 6 and the hanging member 7. The holding structure 6 has a pair of holding claws 6a. When the pair of holding claws 6a are closed as shown in the figure, they suspend and support the glass plates G and protective sheets S; when the pair of holding claws 6a are open, their suspension and support are released. The force sensor 8 measures the total weight of the suspended glass plates G and protective sheets S. In this embodiment, the force sensor 8 and the holding structure 6 are installed at multiple locations (e.g., two to five locations) in the width direction of the hanging member 7. Specifically, the hanging member 7 is a single component, and its upper end engages with a track. Furthermore, the length of the lower end 7a of the suspension member 7 in the width direction is the same as the length of the glass plate G in the width direction, and force sensors 8 and holding structures 6 are respectively installed at multiple locations in the width direction of the lower end 7a. Therefore, the total value measured by the multiple force sensors 8 is the total weight of a set of glass plates G and protective sheets S. In addition, the suspension member 7 is designed to move in the vertical direction.

[0046] The attitude conversion stage 4 changes the glass plate G and protective sheet S, which are handed over from the transport unit 3 in a longitudinal orientation, to a flat orientation. Specifically, the attitude conversion stage 4 is rotatable about the support shaft 10. The support shaft 10 is mounted on the rear end and upper corner 9a of the support platform 9, which is rectangular in side view. The attitude conversion stage 4 has a longitudinally elongated main body 4a and a base plate 4b protruding rearward from the lower end of the main body 4a. The main body 4a has a receiving surface 4aa for receiving the glass plate G and protective sheet S. The base plate 4b has a supporting surface 4ba for receiving the lower ends of the glass plate G and protective sheet S. As shown, when the glass plate G and protective sheet S are handed over, the receiving surface 4aa of the attitude conversion stage 4 becomes an inclined surface that tilts forward as it faces upward, and the supporting surface 4ba of the attitude conversion stage 4 becomes an inclined surface that tilts upward as it faces rearward. Therefore, at the time of handover to the attitude conversion stage 4, the glass plate G and protective sheet S are in a forward-tilted orientation with their upper ends positioned forward of their lower ends. In this case, the tilt angle of the receiving surface 4aa is preferably 45° to 88° relative to the horizontal plane, and more preferably 75° to 88° relative to the horizontal plane. From this state, the attitude conversion platform 4 rotates about the support axis 10 in the direction of arrow C, and stops at the point when the rear protrusion 4x of the main body 4a abuts against the upper surface 9b of the support platform 9.

[0047] Adsorption pad 5 becomes in Figure 1 The structure shown moves between the retraction position and the holding position described later. The movement of the adsorption pad 5 is achieved by a robotic arm or the like. The adsorption pad 5 uses the attractive force generated by negative pressure to adsorb and hold a set of glass plates G and protective sheets S.

[0048] Next, the manufacturing method of the glass plate using the manufacturing apparatus having the above-described structure will be described in detail.

[0049] The manufacturing method of glass plates includes a separation process, a handling process, a weight measurement process, a breakage detection process, a handover process, a posture conversion process, and a delivery process. The separation process is the process of separating at least the upper ends of a set of glass plates G and protective sheets S from the glass plate stack 2 loaded on tray 1. The handling process is the process of removing and handling a set of glass plates G and protective sheets S from the glass plate stack 2 after the separation process. The weight measurement process is the process of measuring the total weight of the set of glass plates G and protective sheets S handled in the handling process. The breakage detection process is the process of detecting whether any breakage has occurred in the glass plate G based on the results of the weight measurement process. The handover process is the process of handing over a set of glass plates G and protective sheets S after the handling process. The posture conversion process is the process of changing the posture of a set of glass plates G and protective sheets S after the handover process. The delivery process is the process of sending the set of glass plates G and protective sheets S, after the posture conversion process, toward the work area of ​​the subsequent process where the glass plate G is processed.

[0050] Figure 2 This is a side view showing the separation process. As shown in the figure, in the separation process, as indicated by the dashed line, the adsorption pad 5 adsorbs and holds a set of glass plates G and protective sheets S overlapping on the front side of the glass plate G. From this state, the adsorption pad 5 moves forward, thereby separating the upper portions of the glass plates G and protective sheets S from the glass plate stack 2 as indicated by the solid line. In this state, the pair of gripping claws 6a of the transport unit 3 changes from the open state shown by the solid line to the closed state shown by the dashed line, thereby holding the upper ends of the glass plates G and protective sheets S by the pair of gripping claws 6a. It should be noted that in this embodiment, the glass plate G is flexible, so the glass plate G and protective sheets S at the point when their upper ends are held by the pair of gripping claws 6a are in the shape shown in the figure. In contrast, when the glass plate G is not flexible, the glass plates G and protective sheets S separate from the glass plate stack 2 along their entire vertical length when their lower ends contact the lower end support surface 1aa of the tray 1. In any of these cases, the distance by which the upper ends of the glass plate G and the protective sheet S are separated from the glass plate laminate 2 is the distance that the pair of gripping claws 6a of the conveying unit 3 can hold the upper ends of the glass plate G and the protective sheet S.

[0051] Figure 3 This is a side view showing the implementation of the transport process in a time sequence. During the transport process, a weight measurement process is performed, and based on the results, the glass plate G is tested for breakage in a breakage detection process. As shown in the figure, in the transport process, firstly, a pair of gripping claws 6a of the transport unit 3 grips the upper ends of the glass plate G and the protective sheet S, which are separated from the glass plate laminate 2 by the adsorption pad 5. In this state, the transport unit 3 removes both the glass plate G and the protective sheet S from the glass plate laminate 2 and suspends them in a longitudinal posture, and transports them to the perimeter of the setting location of the posture conversion table 4. The transport path K in this case has: an ascending path K1, which gradually rises in the transport direction in the first part of the transport process; and a descending path K2, which gradually descends in the transport direction in the second part of the transport process. When comparing the two paths K1 and K2, the transport speed of the descending path K2 is higher than that of the ascending path K1. Furthermore, the transport speed gradually increases to high speed along the ascending path K1, while the transport speed remains constant along the descending path K2. It should be noted that after the transport unit 3 reaches the end of the descending path K2 and hands over the glass plate G and protective sheet S to the attitude conversion table 4 in the handover process described later, it moves backward and returns to the vicinity of the tray 1's placement area. Afterward, the transport unit 3 again removes and transports the glass plate G and protective sheet S from the glass plate stack 2 in the same sequence.

[0052] In the weight measurement process, the combined weight of the glass plate G and the protective sheet S is measured using a force sensor 8 along the descent path K2 of the aforementioned transport path K. In the breakage detection process, the measurement results are used to detect whether the glass plate G has broken. The reason why measuring the combined weight of the glass plate G and the protective sheet S allows for accurate detection of breakage in the glass plate G is as follows: If the glass plate G breaks during transport in the transport process, the broken portion falls, making it lighter than an unbroken glass plate G. Conversely, even if the protective sheet S is damaged, the damaged portion usually does not fall, and even if it does fall, the weight of the fallen portion is minimal, so the weight of the protective sheet S can be considered unchanged. Therefore, by measuring the combined weight of the glass plate G and the protective sheet S, breakage of the glass plate G can be accurately detected regardless of the weight of the protective sheet S. Furthermore, the reason for measuring the weight of the glass plate G and the protective sheet S along the descent path K2 is as follows. That is, in the ascending path K1, which is traversed before sufficient time has elapsed after the glass plate laminate 2 is removed, the weight of the glass plate G and the protective sheet S varies considerably due to various external factors. In contrast, in the descending path K2, which is traversed after sufficient time has elapsed after the glass plate laminate 2 is removed, the weight of the glass plate G and the protective sheet S varies less. Therefore, by measuring the weight of the glass plate G and the protective sheet S in a stable state in the descending path K2, it is possible to accurately detect glass plate breakage. In this case, in the descending path K2, at its leading end in the transport direction (for example, the part indicated by reference numeral D in the figure), the glass plate G and the protective sheet S are less susceptible to wind pressure and are therefore in an untilted state. Therefore, at the leading end in the transport direction of the descending path K2, the weight of the glass plate G and the protective sheet S is most stable; therefore, if weight measurement is performed at this location, it is possible to further accurately detect glass plate G breakage. Furthermore, this transport process also provides advantages as described below. That is, a protective sheet S is superimposed on the front side of the glass plate G, thus placing the protective sheet S in a state where it is difficult to detect the breakage of the glass plate G using a camera, sensor, etc. However, if the weight of the glass plate G and the protective sheet S is measured, the breakage of the glass plate G can be accurately detected without being obstructed by the protective sheet S.

[0053] When performing the weight measurement and breakage detection processes during the handling process, the following procedure is also followed. Specifically, when detecting whether glass plate G has broken, the weight of the glass plate G and protective sheet S measured during the initial handling is compared with the weight of the glass plate G and protective sheet S measured during the subsequent handling. This comparison ensures that even if there is a weight difference between the glass plate G and protective sheet S initially removed from the glass plate laminate 2 and those removed later, due to deviations in the manufacturing conditions of the glass plate G, and this weight difference is unacceptable, the breakage of the glass plate G can be detected without being affected. Furthermore, in this case, the operator visually inspects the glass plate G to check for breakage. The weight of the glass plate G and protective sheet S in cases where no breakage is found is then compared with the weight of the glass plate G and protective sheet S measured during the subsequent handling. In this way, after visually confirming that the glass plate G has not cracked, the weight of the glass plate G and the protective sheet S are compared as a benchmark, thus preventing false detections of cracking. Alternatively, if the glass plate G is found to be cracked based on the operator's visual observation, its weight at that point is compared as a benchmark once a subsequent observation confirms that it has not cracked.

[0054] Figure 4 This is a side view showing the handover process. In the handover process, as shown by the solid lines in the figure, the glass plate G and protective sheet S, suspended and supported by the transport unit 3 at the end of the transport process, are handed over to the attitude conversion table 4 in an inclined posture, as shown by the dashed lines in the figure, accompanied by the opening action of a pair of gripping claws 6a. Alternatively, as described previously, an adsorption pad can be used to gradually transfer the upper portions of the glass plate G and protective sheet S along the receiving surface 4aa of the attitude conversion table 4. Afterwards, in the attitude conversion process, the attitude conversion table 4 rotates about the support axis 10 in the direction of arrow C. Furthermore, as... Figure 5As shown, at the point when the rear protrusion 4x of the main body 4a abuts against and stops on the upper surface 9b of the support platform 9, the receiving surface 4aa becomes a horizontal surface (preferably a horizontal surface). Thus, the glass plate G and the protective sheet S change from the aforementioned inclined posture to a flat posture. At this point, the glass plate G is placed on the protective sheet S. From this state, in the feeding process, while maintaining the glass plate G on the protective sheet S, it is fed forward from the posture conversion table 4 by a conveyor (not shown). The fed-out glass plate G and the protective sheet S are transported towards the work area of ​​the next process by a conveyor (e.g., a roller conveyor, a belt conveyor) while maintaining a flat posture. In the next process, the glass plate G undergoes end-face processing, etching, etc.

[0055] Figure 6 This is a perspective view showing the manufacturing apparatus of the above-described embodiment in further detail, and with new constituent elements added to the manufacturing apparatus. It should be noted that the structure of this manufacturing apparatus, except for the matters described below, is different from that already described... Figures 1-5 The manufacturing apparatus shown is the same, therefore the common constituent elements in both are... Figure 6The same reference numerals are used in the accompanying drawings, and their descriptions are omitted. As shown in the figure, the manufacturing apparatus is structured as follows: a first track structure 12 has two first tracks 11 extending in the front-rear direction, and a sliding member 13 disposed above it is guided by the first tracks 11 to move in the front-rear direction. Furthermore, the manufacturing apparatus is structured as follows: two second tracks 14 extend in a width direction orthogonal to the front-rear direction, and the first track structure 12 disposed above them is guided by the second tracks 14 to move in the width direction. A support column 15 extending in the vertical direction is held on the sliding member 13, and a horizontal stack 16 extending in the width direction is mounted at the lower end of the support column 15. The support column 15 forms the upper part of the hanging member 7, and the horizontal stack 16 forms the lower end 7a of the hanging member 7. Multiple gripping structures 6 (gripping claws 6a) are mounted on the horizontal stack 16. In this manufacturing apparatus, the transport unit 3, as described above, is composed of the sliding member 13, the support column 15, the horizontal stack 16, and the multiple gripping structures 6. Therefore, the conveying unit 3 becomes a structure that moves not only in the front-to-back direction as described, but also in the width direction. Furthermore, although not shown, the support column 15 is held in place of the sliding member 13 in a manner that allows it to move in the vertical direction, or, based on the support column 15 being fixed to the sliding member 13, it is configured such that two second tracks 14 can move vertically together with the first track structure 12, thereby allowing the conveying unit 3 to also move vertically. Moreover, the force sensor (not shown), which serves as the weight measuring mechanism, can be installed between the multiple holding structures 6 and the horizontal stack 16 (the lower end 7a of the hanging member 7) as described previously, or it can be installed instead at the position between the sliding member 13 and the horizontal stack 16 in the support column 15. If the force sensor is installed on the support column 15, the number of force sensors can be reduced (for example, to one).

[0056] Under the structure of this manufacturing apparatus, multiple trays 1X and 1Y (two in the illustration) loaded with glass plate laminates 2 are arranged side-by-side along the width direction. Furthermore, in the illustration, the two trays 1X and 1Y, and the attitude conversion table 4 in front of them, are arranged such that the center of the gap between the two trays 1X and 1Y in the width direction coincides with the center of the attitude conversion table 4 in the width direction. The transport unit 3 first repeatedly performs the action of removing a set of glass plates G and protective sheets S from the glass plate laminate 2 loaded on one tray 1X and transporting it forward while simultaneously measuring its weight. Through this repeated action, at the point when the glass plate laminate 2 on one tray 1X is emptied, the transport unit 3 moves along the width direction to the arrangement position of the other tray 1Y and repeats the same weight measurement action. When there are other trays, the transport unit 3 performs the same operation. Therefore, while the operation of replacing the empty pallet 1X with a new pallet containing the glass plate stack 2 is being carried out, the transport unit 3 can also continue to transport a set of glass plates G and protective sheets S, so there is no waiting time and the operation efficiency is good.

[0057] Figure 7 This is a top view schematically illustrating, in chronological order, the state of the transport unit 3 transporting glass plates G and protective sheets S under the condition of the structure of this manufacturing apparatus. It should be noted that this figure illustrates the state in which a set of glass plates G and protective sheets S are held by the three gripping claws 6a of the transport unit 3. As shown by the solid lines in the figure, the set of glass plates G and protective sheets S taken from one of the trays 1X first moves forward in the upstream part of the transport path as indicated by arrow X1. Then, in the middle part of the transport path, it moves diagonally forward (diagonally forward towards the center side in the width direction) as indicated by arrow X2. Moreover, in the downstream part of the transport path, it moves forward again as indicated by arrow X3. The aforementioned diagonally forward movement is achieved through... Figure 6 The sliding member 13 shown, and thus the conveying unit 3, moves forward along the first track 11 while simultaneously moving along the second track 14 in the width direction. Furthermore, this forward diagonal movement is as described above. Figure 3 In the illustrated handling method, the movement occurs during the period when the handling unit 3 moves from, for example, the position indicated by reference numeral E in the figure to the position indicated by reference numeral D. Thus, the glass plate G moves diagonally forward without contacting the tray 1 (1X) and the attitude conversion table 4. Therefore, it is possible to suppress the impact that could cause the glass plate G to break due to movement while in contact with the tray 1 (1X) and the attitude conversion table 4. It should be noted that... Figure 7When one of the trays 1X is empty, as shown by the dotted line in the figure, the other tray 1Y, in the same manner as described above, makes a forward movement as indicated by arrow X1, a diagonal forward movement as indicated by arrow X2 (towards the center side in the width direction), and then makes another forward movement as indicated by arrow X3.

[0058] The manufacturing method of glass articles according to the embodiments of the present invention has been described above, but the present invention is not limited thereto, and various modifications can be made without departing from its spirit.

[0059] For example, in the above embodiments, a set of glass plates G and protective sheets S are held and transported by a pair of gripping claws 6a of the transport unit 3. Alternatively, other components (such as suction pads for negative pressure attraction) may be installed on the transport unit 3, and these other components may hold and transport the set of glass plates G and protective sheets S.

[0060] In the above embodiments, the transport unit 3 removes a set of glass plates G and protective sheets from the glass plate stack 2 loaded on the tray 1 in a longitudinal (tilted) position and transports them in a longitudinal position. However, the transport unit 3 may also remove a set of glass plates G and protective sheets S from the glass plate stack 2 loaded on the tray 1 in a horizontal position and transport them in a horizontal position. In this case, the transport unit 3 may be equipped with, for example, multiple suction pads that perform negative pressure suction. After the glass plates G and protective sheets S are held in a horizontal position by these suction pads, the weight acting on these suction pads may be measured using a force sensor 8 or the like.

[0061] In the above embodiments, the weights of the glass plates G and protective sheets S measured during the initial handling are compared with the weights of the glass plates G and protective sheets S measured during the subsequent handling to detect breakage of the glass plate G. Alternatively, a moving average of the weights of a predetermined number of sheets (e.g., 3 to 30 sheets) measured during the initial handling can be calculated, and breakage of the glass plate G can be detected if the weight deviates from a threshold determined therefrom. In this case, when calculating the moving average of the weights of the predetermined number of sheets measured during the initial handling, the moving average of the weights of the predetermined number of sheets can be calculated without omitting any broken glass plates G.

[0062] In the above embodiments, the operator visually observes the glass plate G to check whether the glass plate G has cracked. The weight of the glass plate G and the protective sheet S when the inspection result shows that no crack has occurred is compared with the weight of the glass plate G and the protective sheet S measured in the group that was transported later than these glass plates G and the protective sheet S. Alternatively, the weight of the glass plate G and the protective sheet S when the inspection result shows that no crack has occurred can be compared with the weight of the glass plate G and the protective sheet S measured in the group that was transported earlier than these glass plates G and the protective sheet S.

[0063] In the above embodiments, the location for measuring the weight of the glass plate G and the protective sheet S is set at a point on the descent path K2 of the transport path K. However, the weight measurement location can be changed as needed. In such cases, multiple (e.g., about 10 locations) weight measurement locations can be prepared in advance, with measurements always performed at one location and measurements taken at other locations as needed. It should be noted that in this case, locations other than the descent path K2 in the transport path K may also be included.

[0064] In the above embodiments, the transport unit 3 transports a set of glass plates G and protective sheets S in sequence. However, it is also possible that the transport unit 3 transports only one glass plate G in sequence. In this case, it is preferable to remove one protective sheet S that is arranged alternately with the glass plates on the tray 1 each time a glass plate G is removed.

[0065] In the above embodiments, a force sensor 8 is used as a weight measuring mechanism, but other weight measuring instruments such as crane scales can also be used.

[0066] Explanation of reference numerals in the attached figures

[0067] 1 pallet

[0068] 1X Tray

[0069] 1Y tray

[0070] 2. Glass plate laminate

[0071] 3. Handling Unit

[0072] 8. Force sensor (weight measuring mechanism)

[0073] G glass plate

[0074] S Protective Film

[0075] K Transport path

[0076] K1 Ascending Path

[0077] K2 descent path.

Claims

1. A method for manufacturing a glass plate, comprising a handling step of sequentially removing glass plates from a glass plate stack loaded on a tray and transporting them in a suspended and supported state. The method for manufacturing the glass plate is characterized in that, The glass plate in the transport process has an ascending path that rises in the transport direction and a descending path that falls in the transport direction after passing through the ascending path. Based on the weight of the glass plate measured during the descent path, it is determined whether the glass plate has cracked.

2. The method for manufacturing a glass plate according to claim 1, wherein, When detecting whether the glass plate has cracked, the weight of the glass plate measured by the first glass plate is compared with the weight of the glass plate measured by the next glass plate after it is transported.

3. The method for manufacturing a glass plate according to claim 2, wherein, The glass plate is visually inspected to check for cracks, and the weight of the glass plate that is found to be unbroken is compared with the weight of the glass plate that was transported after it.

4. The method for manufacturing a glass plate according to any one of claims 1 to 3, wherein, In the transport process, the weight of the glass plate is measured using a weight measuring mechanism installed in the suspension part used to suspend the glass plate.

5. The method for manufacturing a glass plate according to claim 4, wherein, The glass plate is transported in a direction orthogonal to the main surface of the glass plate.

6. The method for manufacturing a glass plate according to any one of claims 1 to 3, wherein, Based on the weight of the glass plate measured at the leading end of the transport direction in the descent path, it is detected whether the glass plate has cracked.

7. The method for manufacturing a glass plate according to any one of claims 1 to 3, wherein, The glass plate stack is formed by alternating glass plates and protective sheets. In the handling process, the protective sheets are sequentially stacked on top of the glass plates and taken out and handled together. The weight of the glass plates plus the weight of the protective sheets are measured.

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