Glass plate manufacturing method and glass plate package

Abstract

This glass plate manufacturing method includes: alternately arranging an original glass plate 7 and a protective sheet 8 in a vertical attitude so as to produce a laminated body; taking out the original glass plate 7 and the protective sheet 8 from a laminated body 9; cutting the glass original plate 7 in a state where the glass original plate 7 is stacked on the protective sheet 8 in a horizontal mounted attitude so as to divide said original glass plate into a glass plate 13 and an unnecessary part 14; and thereafter removing the unnecessary part 14 from the protective sheet 8. When the original glass plate 7 is cut, the shape of the protective sheet 8 on one side is configured to cause a corner part 7d of the original glass plate 7 on one side to project from the protective sheet 8, and said one side is the upper side of the original glass plate 7 and the protective sheet 8 when both of 7 and 8 were in the vertical attitude.

Description

[Technical field]

[0001] The present invention relates to an improvement in the shape of a protective sheet when a glass original plate is superimposed on the protective sheet for work, and to an improvement in the shape of the protective sheet in a glass plate package having a laminate in which protective sheets and glass original plates are arranged alternately. [Background technology]

[0002] In the field of glass plate manufacturing, glass original plates cut from a glass ribbon formed by a down-draw method, a float method, or the like are sometimes stacked together with a protective sheet on a pallet or the like, and then both are removed and subjected to various operations. As a specific example of a stack, Patent Document 1 discloses that glass plates (glass original plates) and protective sheets are alternately arranged in a vertical position (inclined position).

[0003] Among the various operations performed on the glass original plates taken out one by one together with the protective sheets from this type of laminate, there is an operation in which the posture of both is changed from a vertical posture to a flat posture. As a specific example of such an operation, for example, Patent Document 2 discloses a method in which the glass original plate is placed on the protective sheet in a flat posture, a scribe line is formed on the upper surface of the glass original plate, and then the glass original plate is bent and broken along the scribe line.

[0004] In the process of cutting the glass original sheet on the protective sheet in this way, both ends in the width direction of the glass original sheet are cut off as unnecessary parts, and after cutting, the unnecessary parts are sometimes removed from above the protective sheet. By carrying out such a process, a glass sheet can be obtained as a product. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-104566 A [Patent Document 2] JP 2017-190255 A Summary of the Invention [Problem to be solved by the invention]

[0006] According to Patent Document 1, in a laminate consisting of a vertically oriented original glass plate and a protective sheet, the upper end and both widthwise ends of the protective sheet protrude from both upper corners of the original glass plate. The cutting operation disclosed in Patent Document 2 is performed by removing both of the above-mentioned components from such a laminate in their original state and changing their positions to a flat position.

[0007] Under such circumstances, when performing a cutting operation that requires bending deformation or the like on the glass original sheet, for example, a folding operation, a corner on one side of the glass original sheet (a corner on the upper side of the glass original sheet when it is in a vertical position) may pierce the protective sheet. Therefore, when folding the glass original sheet along the scribe line, the corner on one side of the glass original sheet is caught by the protective sheet, which hinders smooth operation. Furthermore, when removing the unnecessary part by lifting it from the protective sheet with a holder such as a suction pad or a gripping member after folding, the corner of the unnecessary part may be caught by the protective sheet, which may cause the unnecessary part to fall off the holder. Even if the unnecessary part does not fall off the holder, the unnecessary part may be unduly deformed and broken due to the above-mentioned catch. In this case, glass powder falls and adheres to the glass sheet as a product, which not only reduces the quality of the glass sheet but also causes defective products.

[0008] From the above viewpoints, the present invention aims to facilitate various operations by making it difficult for the glass original plate and the protective sheet to get caught between each other when performing various operations on the glass original plate after removing them from a stack in which the glass original plate and the protective sheet are alternately arranged in a vertical position. [Means for solving the problem]

[0009] A first aspect of the present invention, which has been invented to solve the above-mentioned problems, is a method for manufacturing a glass plate, comprising: a preparation step of preparing a laminate in which glass original plates and protective sheets are alternately arranged in a vertical position; a removal step of removing the glass original plate and the protective sheet from the laminate after the preparation step; a cutting step of cutting the glass original plate in a state in which the glass original plate is laid flat on the protective sheet and dividing it into a glass plate and an unnecessary portion after the removal step; and a removal step of removing the unnecessary portion from the protective sheet after the cutting step, wherein in the cutting step, one side of the protective sheet is configured to have a corner portion on one side of the glass original plate protrude from the protective sheet, and the one side is an upper side of both the glass original plate and the protective sheet when they are in the vertical position.

[0010] According to this method, a set of glass original sheets and protective sheets taken out from a laminate in which the glass original sheets and protective sheets are alternately arranged in a vertical position is stacked in a flat position and a cutting process is performed. When performing this cutting process, since the corners on one side of the glass original sheet protrude from the protective sheet, the corners on one side of the glass original sheet are prevented from piercing the protective sheet. Here, "one side" refers to the upper side of both when the glass original sheet and the protective sheet are stacked in a vertical position. In this case, even if the cutting work performed in the cutting process is an operation that causes bending deformation or the like in the glass original sheet, such as folding and breaking, the glass original sheet is prevented from getting caught on the protective sheet on that one side, and the cutting work is facilitated. In addition, in the removal process after the cutting process, an operation of lifting and removing the unnecessary part is performed using a holding tool such as a suction pad or a gripping member. In this case, the corners on one side of the unnecessary part (the part that was the corner on one side of the glass original sheet) are prevented from getting caught on the protective sheet. This prevents the unnecessary parts from falling off the holder, breakage due to undue deformation of the unnecessary parts, adhesion of glass powder to the glass plate as a product, etc. As a result, inefficient interruptions of the work in the cutting and removing processes are prevented, and deterioration of the quality of the glass plate as a product and the occurrence of defective products are suppressed.

[0011] In the above-described method, in the preparing step, an upper corner of a protective sheet may be cut off to prepare the protective sheet to be used in the cutting step.

[0012] In this way, the protective sheet in the laminate before the preparation step has its upper corners not cut off, and this protective sheet can cover the entire upper area of ​​the original glass plate, thereby allowing the upper side of the glass plate to be appropriately protected by the protective sheet during transport or transportation of the laminate.

[0013] In the above-described method, the one side of the protective sheet used in the cutting step may be configured such that one corner of the product area of ​​the original glass plate protrudes from the protective sheet.

[0014] In this way, after the removal step, the corner portion on one side of the glass plate corresponding to the product area of ​​the original glass plate still protrudes from the protective sheet, so that when performing work on the glass plate after the removal step, the corner portion on one side of the glass plate does not pierce the protective sheet, and the work after the removal step can be performed smoothly.

[0015] In this method, in the cutting process, the shape of the other side of the protective sheet is such that the corner portion of the other side of the glass original plate protrudes from the protective sheet, and the other side may be the underside of both the glass original plate and the protective sheet when they are in the vertical position.

[0016] In this way, it is possible to prevent the corners of the glass original plate from piercing the protective sheet on the other side of the two plates, which makes it possible to avoid, on the other side, the difficulty of the cutting operation, the falling off of the unnecessary parts from the holders such as the suction pads and the gripping members, breakage due to the undesired deformation of the unnecessary parts, and the adhesion of glass powder to the glass plate as a product.

[0017] In the above-described method, in the preparing step, a lower corner of a protection sheet may be cut off to prepare the protection sheet to be used in the cutting step.

[0018] In this way, the protective sheet in the laminate before the preparation step has its lower corners not cut off, and this protective sheet can cover the entire lower area of ​​the original glass plate, thereby allowing the protective sheet to adequately protect the lower side of the glass plate during transport or shipping of the laminate.

[0019] In the above-described method, the other side of the protective sheet used in the cutting step may be configured such that a corner portion of the other side of the product area of ​​the glass original plate protrudes from the protective sheet.

[0020] In this way, after the removal step, the corner portion on the other side of the glass plate corresponding to the product area of ​​the original glass plate still protrudes from the protective sheet, so that when performing work on the glass plate after the removal step, the corner portion on the other side of the glass plate does not pierce the protective sheet, and the work after the removal step can be performed smoothly.

[0021] Furthermore, as a step subsequent to the removal step, the method may include a separation step in which the glass plate is placed flat on the protective sheet used in the cutting step in the above-mentioned glass plate manufacturing method, instead of the glass original plate, and the two are transported with the one side as the front side in the transport direction, and during the transport, the traveling directions of the two are made different, so that separation of the protective sheet is initiated from the end of the glass plate at the front side in the transport direction, thereby separating the two.

[0022] In this way, the operation of separating the protective sheet from the glass plate can be performed smoothly. That is, when the glass plate is transported in a state in which it is stacked on the protective sheet, if the corner of the glass plate on the front side in the transport direction is pierced into the protective sheet, even if the traveling directions of the two are changed during the transport, the glass plate and the protective sheet may proceed in the same direction. As a result, the protective sheet cannot be separated from the glass plate, and problems such as damage to the glass plate may occur. In the method here, the shape of the front side in the transport direction of the protective sheet is a shape in which the corner of the glass original plate on the front side in the transport direction protrudes. In this shape, the glass original plate cannot pierce the protective sheet. In this case, the position of the above-mentioned corner of the glass original plate and the above-mentioned corner of the glass plate are merely different by the amount of the unnecessary portion removed. Therefore, the above-mentioned piercing does not occur or is difficult to occur in the glass plate, which contributes to the smooth operation of separating the protective sheet from the glass plate.

[0023] A second aspect of the present invention, which has been devised to solve the above-mentioned problems, is a glass plate package in which a stack in which glass original plates and protective sheets are arranged alternately in a vertical position is loaded onto a packaging pallet, and is characterized in that the shape of the upper side of the protective sheet is such that the upper corners of the glass original plates protrude from the protective sheet.

[0024] According to this glass sheet package, the protective sheet and the glass sheet can be taken out as they are, and after changing the posture from vertical to flat, the glass sheet can be cut and the unnecessary part can be removed from the protective sheet. This prevents the corner of one side of the glass sheet from being stuck into the protective sheet, and provides the same advantages as those described above. In addition, if the upper side of the protective sheet and the glass sheet is the front side in the conveying direction, the protective sheet can be smoothly separated from the glass sheet. Effect of the Invention

[0025] According to the present invention, when performing various operations on a glass original plate after removing both the glass original plate and the protective sheet from a stack in which the glass original plate and the protective sheet are alternately arranged in a vertical position, the two are less likely to get caught on each other, making it possible to perform various operations more smoothly. [Brief description of the drawings]

[0026] [Figure 1] 2 is a flowchart showing a method for manufacturing a glass plate according to an embodiment of the present invention. [Diagram 2] 1 is a schematic side view showing a glass plate package according to an embodiment of the present invention. [Figure 3a] 3 is a vertical sectional front view of the glass plate package taken along line AA in FIG. 2. [Figure 3b] 3 is an enlarged front view showing a main part of the glass plate package taken along line AA in FIG. 2. [Figure 4a] FIG. 2 is a vertical sectional front view showing a first other example of a glass plate package according to an embodiment of the present invention. [Figure 4b] FIG. 2 is an enlarged front view showing a main part of a first other example of a glass plate package according to an embodiment of the present invention. [Figure 5a] FIG. 11 is a vertical sectional front view showing a second other example of a glass plate package according to an embodiment of the present invention. [Figure 5b] FIG. 4 is an enlarged front view showing a main part of a second other example of a glass plate package according to an embodiment of the present invention. [Figure 6a] FIG. 11 is a vertical sectional front view showing a third other example of a glass plate package according to an embodiment of the present invention. [Figure 6b] FIG. 11 is an enlarged front view showing a main part of a third other example of a glass plate package according to an embodiment of the present invention. [Figure 7a] FIG. 2 is a schematic perspective view showing an aspect in which a cutting step is being performed in the glass plate manufacturing method according to the embodiment of the present invention. [Figure 7b] FIG. 2 is a schematic perspective view showing an aspect in which a cutting step is being performed in the glass plate manufacturing method according to the embodiment of the present invention. [Figure 8]FIG. 2 is a schematic side view showing an aspect in which a separation step is being performed in the glass plate manufacturing method according to the embodiment of the present invention. [Figure 9] FIG. 2 is a schematic side view for explaining a problem that occurs when performing a separation step in the method for producing a glass plate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, a method for producing a glass sheet and a glass sheet package according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0028] The method for manufacturing a glass plate according to this embodiment includes a preparation step 1 for preparing a stack in which original glass plates and protective sheets are alternately arranged in a vertical position on a packaging pallet, and a removal step 2 for removing the original glass plates and protective sheets from the stack, as shown in Fig. 1. Furthermore, this manufacturing method includes a cutting step 3 for cutting the original glass plate into a glass plate and an unnecessary portion while the original glass plate is laid flat on the removed protective sheet, a removal step 4 for removing the unnecessary portion from the protective sheet, and a separation step 5 for separating the protective sheet from the glass plate.

[0029] FIG. 2 is a schematic side view illustrating the glass sheet package 6 prepared in the preparation step 1, and FIG. 3a is a schematic front view cut along the line A-A in FIG. 2. As shown in these figures, the glass sheet package 6 is a stack 9 in which glass original sheets 7 and protective sheets 8 are alternately arranged in a vertical position (specifically, in an inclined position) and loaded on a packaging pallet 10. The glass original sheet 7 is a glass ribbon formed by a down-draw method (e.g., an overflow down-draw method) or a float method, cut along the width direction. As shown in FIG. 3a, both ends 7a in the width direction of the glass original sheet 7 are portions that are considered unnecessary. These both ends 7a are to be separated from the product region 7b by cutting the glass original sheet 7 along the planned cutting line 7c in the cutting step 3.

[0030] The glass plate 7 preferably has a thickness of 100 to 2000 μm, and each side preferably has a length of 1500 to 4000 mm. The protective sheet 8 preferably has a thickness of 100 to 500 μm, and is preferably made of a foamed resin sheet such as polyethylene or a non-foamed resin sheet.

[0031] The configuration of the protective sheet 8 and the original glass plate 7 will be described below. In the following description, the same components as those in the protective sheet 8 and the original glass plate 7 shown in Figures 3a to 6b are denoted by the same reference numerals in each figure. Detailed description of the components denoted by the same reference numerals will be omitted.

[0032] The protective sheet 8 shown in FIG. 3a has an upper shape in which both upper corners 7d of the original glass plate 7 protrude. More specifically, the protective sheet 8 is a rectangular shape with both upper corners of the rectangle missing. The upper corners 7d of the rectangular original glass plate 7 protrude from the missing edge 8a of the upper side of the protective sheet 8. The protruding dimension L1 is preferably 5 to 20 mm. In this case, the upper corners 7d of the original glass plate 7 are contained within the missing portion 8b of the protective sheet 8 shown in FIG. 3b (the portion with parallel diagonal lines) and do not reach the outer edge 8c of the missing portion 8b. Therefore, the upper end 8d and both widthwise ends 8e of the protective sheet 8 protrude from the upper side 7e and both widthwise sides 7f of the original glass plate 7, respectively. The protruding dimension L2 from the upper side 7e is preferably 50 to 150 mm, and the protruding dimension L3 from the sides 7f on both sides in the width direction is preferably 50 to 200 mm. In this case, the corner 7g (upper corner of the product area 7b) formed by the upper side 7e of the glass original plate 7 and the planned cutting line 7c does not protrude from the upper missing edge 8a of the protective sheet 8. The distance L4 from the top of this corner 7g to the edge 8a is preferably 10 mm or less. As shown in FIG. 3a, the lower side 8f of the protective sheet 8 and the lower side 7h of the glass original plate 7 are in contact or approximately in contact with the placement surface 10a of the packing pallet 10, so that they are in the same position or approximately in the same position. In this case, in the illustrated example, the lower side 8f of the protective sheet 8 is in contact with the placement surface 10a, and the lower side 7h of the glass original plate 7 is spaced upward from the placement surface 10a. In other words, the lower end including the lower side 8f of the protective sheet 8 protrudes beyond the lower side 7h of the original glass plate 7. Contrary to the illustrated example, the lower side 8f of the protective sheet 8 may be spaced upward from the mounting surface 10a and the lower side 7h of the original glass plate 7 may be in contact with the mounting surface 10a. In other words, the lower end including the lower side 7h of the original glass plate 7 may protrude beyond the lower side 8f of the protective sheet 8.

[0033] In this embodiment, in the preparation step 1, the corners of the rectangular protective sheet are cut off to remove the corners. Therefore, when the glass plate package 6 is transported or shipped, the entire upper end portion and the entire widthwise end portions of the rectangular protective sheet protrude from the upper side 7e and both widthwise sides 7f of the original glass plate 7. This results in the entire glass plate 7 being covered by the protective sheet, and the original glass plate 7 is appropriately protected.

[0034] Incidentally, the corners of the rectangular protective sheet may be cut off during the removal step 2 or after the removal step 2 and before the cutting step 3. This cutting operation may be performed manually by an operator or by using a robot hand or the like. Furthermore, when producing the laminate 9, a protective sheet 8 with a missing corner as shown in the figure may be used instead of a rectangular protective sheet. Incidentally, the missing edge 8a on the upper side of the protective sheet 8 has a shape that follows a straight line in the illustrated example, but may also have a wave shape, a sawtooth shape, an arc shape, or the like.

[0035] The form of the protective sheet 8 is not limited to the above form, and may be the form shown below. That is, the protective sheet 8 shown in FIG. 4a is one in which both upper corners are missing as well as both lower corners. As shown in FIG. 4b, the form of the lower side of this protective sheet 8 is such that the lower end of the missing part (the part with parallel diagonal lines) 8g is located near the lower corner 7i of the original glass plate 7. More specifically, the lower end 8i of the missing edge 8h on the lower side of this protective sheet 8 coincides or approximately coincides with the apex of the lower corner 7i of the original glass plate 7. In this case, in the illustrated example, the lower side 8f of the protective sheet 8 contacts the mounting surface 10a, and the lower side 7h of the original glass plate 7 is separated upward from the mounting surface 10a, and further, the missing edge 8h on the lower side of the protective sheet 8 contacts the apex of the lower corner 7i of the original glass plate 7. Contrary to the illustrated example, the lower side 8f of the protective sheet 8 may be spaced upward from the mounting surface 10a and the lower side 7h of the original glass plate 7 may be in contact with the mounting surface 10a, in which case the lower end 8i of the edge 8h of the protective sheet 8 may be in contact with the side 7f on one side in the width direction of the lower end of the original glass plate 7. The shape of the upper side of this protective sheet 8 is the same as that shown in Figures 3a and 3b. The method of chipping off the lower corner of this protective sheet 8, the timing of chipping off, and the shape of the edge 8h are the same as those already explained for the upper corner of the protective sheet 8 shown in Figures 3a and 3b.

[0036] The protective sheet 8 shown in FIG. 5a has an upper shape in which both upper corners 7g of the product area 7b of the original glass plate 7 are protruding. Therefore, as shown in FIG. 5b, both the upper corners 7d of the original glass plate 7 and the upper corners 7g of the product area 7b are contained in the upper missing portion 8b of the protective sheet 8 (areas with parallel diagonal lines in a dashed line) and do not reach the outer edge 8c of the missing portion 8b. The protruding dimension L5 of the upper corners 7g of the product area 7b is preferably 1 to 10 mm. In this case, as shown in FIG. 5a, the lower side 8f of the protective sheet 8 is in contact with the mounting surface 10a, and the lower side 7h of the original glass plate 7 is spaced upward from the mounting surface 10a. Note that, contrary to the illustrated example, the lower side 8f of the protective sheet 8 may be spaced upward from the mounting surface 10a, and the lower side 7h of the original glass plate 7 may be in contact with the mounting surface 10a. Furthermore, in the illustrated example, the lower corner 8j of this protective sheet 8 is not missing, but the lower corner 8j may be missing as in the protective sheet 8 shown in Figures 4a and 4b. Note that the method for missing the upper corner of this protective sheet 8, the timing for missing, and the shape of the edge 8a are the same as those already explained for the upper corner of the protective sheet 8 shown in Figures 3a and 3b.

[0037] In addition to the upper shape, the lower shape of the protective sheet 8 shown in FIG. 6a is also configured so that both lower corners 7j of the product area 7b of the original glass plate 7 protrude. Therefore, as shown in FIG. 6b, both the lower corners 7i of the original glass plate 7 and the lower corners 7j of the product area 7b are contained in the lower missing portion 8g (area with parallel diagonal lines) of the protective sheet 8, and do not reach the outer edge 8k of the missing portion 8g. The protruding dimension L6 of the lower corners 7j of the product area 7b from the edge 8h is preferably 1 to 10 mm. The lower shape of the protective sheet 8 may be configured so that only the lower corners 7i of the original glass plate 7 protrude. In this case, the protruding dimension of the lower corners 7i is preferably 5 to 20 mm, and the distance from the lower corners 7i to the edge 8h is preferably 10 mm or less. In the illustrated example, the shape of the upper side of the protective sheet 8 is the same as that of the protective sheet 8 shown in Figs. 5a and 5b. The shape of the upper side of the protective sheet 8 may be the same as that of the protective sheet 8 shown in Figs. 3a and 3b. Here, the lower side 8f of the protective sheet 8 and the lower side 7h of the original glass plate 7 are at the same position or approximately the same position. In this case, in the example shown in Figs. 6a and 6b, the lower side 8f of the protective sheet 8 contacts the mounting surface 10a and the lower side 7h of the original glass plate 7 is spaced upward from the mounting surface 10a. Conversely to the illustrated example, the lower side 8f of the protective sheet 8 may be spaced upward from the mounting surface 10a and the lower side 7h of the original glass plate 7 may be in contact with the mounting surface 10a. Alternatively, the following may be used instead. That is, the protective sheet 8 is shifted downward relative to the original glass plate 7 during the execution of the removal step 2, or after the removal step 2 and before the cutting step 3. This ensures that not only the upper side 7e of the original glass plate 7 but also the lower side 7h of the original glass plate 7 is covered by the protective sheet 8. The "upper side" and "lower side" of the protective sheet 8 and the original glass plate 7 described here refer to the upper side and lower side when the protective sheet 8 and the original glass plate 7 are in a vertical position. The method of chipping off the lower corner of the protective sheet 8 and the shape of the edge 8h are the same as those already described for the upper corner of the protective sheet 8 shown in Figures 3a and 3b.

[0038] The removal step 2 is carried out using a device capable of holding the glass original plate 7 and the protective sheet 8 as a set, for example, a device having a suction pad at its tip for suction-holding both the glass original plate 7 and the protective sheet 8, or a device having a gripping member at its tip for gripping both the glass original plate 7 and the protective sheet 8. These devices remove the glass original plate 7 and the protective sheet 8 from the laminate 9 and change their positions so that the glass original plate 7 is laid flat on the protective sheet 8.

[0039] 7a and 7b are perspective views illustrating the state in which the cutting step 3 is being performed. As shown in these figures, in the cutting step 3, the glass original plate 7 is placed on the protective sheet 8 in a flat-laid position on the working surface 11a of the placement unit 11. The placement unit 11 is composed of, for example, a transport conveyor, a work pallet on the conveyor, or a work surface plate. In FIG. 7a, one side of the glass original plate 7 and the protective sheet 8 indicated by the reference symbol B is the upper side of both the protective sheet 8 and the glass original plate 7 when they are in a vertical position. The other side of the glass original plate 7 and the protective sheet 8 indicated by the reference symbol C is the lower side of both the protective sheet 8 and the glass original plate 7 when they are in a vertical position. The glass original plate 7 and the protective sheet 8 here are taken out from the stack 9 described based on FIG. 3a and FIG. 3b, and the relative positional relationship between both the protective sheet 8 and the glass original plate 7 is in the state in which they are arranged in the stack 9. 7a, the other side 8f of the protective sheet 8 and the other side 7h of the glass plate 7 are in the same position or approximately in the same position, but may be the same as the embodiment already described with reference to FIG. original It may protrude from the other side 7h of the plate 7, or an end portion including the other side 7h of the glass original plate 7 may protrude from the other side 8f of the protective sheet 8.

[0040] FIG. 7a illustrates an example of forming a scribe line along the planned cutting line 7c on the surface (upper surface) of the original glass plate 7. In this embodiment, a scribe wheel 12 is moved along the planned cutting line 7c of the original glass plate 7 to form a scribe line 7k along the planned cutting line 7c. In the illustrated example, the scribe line 7k is formed over the entire length of the original glass plate 7 from the other side to one side. The scribe line 7k may be formed in a portion excluding the end of the original glass plate 7 on the other side and the end of the original glass plate 7 on one side. Thereafter, a bending stress is applied to the region of the original glass plate 7 where the scribe line 7k is formed to bend and break the original glass plate 7 along the scribe line 7k, thereby dividing the original glass plate 7 into a glass plate (a glass plate as a product) 13 and an unnecessary portion 14 as shown in FIG. 7b.

[0041] After this, a removal step 4 is performed. In the removal step 4, the unnecessary part 14 is held by a holder such as a suction pad or a gripping member, and then the holder lifts and moves the unnecessary part 14, thereby removing the unnecessary part 14 from the protective sheet 8. Alternatively, in the removal step 4, the unnecessary part 14 may be manually removed from the protective sheet 8 by an operator using a tool, for example.

[0042] The effects of performing cutting step 3 and removing step 4 are as follows. That is, in cutting step 3, as shown in FIG. 7a, one corner 7g of the product area 7b of the glass original plate 7 does not protrude from the missing edge 8a on one side of the protective sheet 8. Therefore, one end of the planned cutting line 7c is supported from below by the protective sheet 8. Moreover, in the illustrated example, the other end of the planned cutting line 7c is also supported from below by the protective sheet 8. As a result, when the scribing wheel 12 is moved along the planned cutting line 7c of the glass original plate 7, it is not adversely affected by the step, and it becomes possible to form the scribe line 7k accurately. This effect is due to the fact that the other end of the protective sheet 8 is supported from below by the protective sheet 8. originalThe same effect can be obtained when the end portion on the other side of the glass original plate 7 protrudes from the other side 7h of the plate 7. Moreover, when the end portion on the other side of the glass original plate 7 protrudes from the other side 8f of the protective sheet 8, the same effect can be obtained by forming the scribe line 7k in a portion excluding the end portion on the other side and the end portion on one side of the glass original plate 7.

[0043] When bending and breaking the glass original plate 7, it is necessary to bend and deform the glass original plate 7 in order to apply bending stress to the region where the scribe line 7k is formed. For this purpose, the corner 7d on one side of the glass original plate 7 protrudes from the missing edge 8a on one side of the protective sheet 8. Therefore, there is no risk that the corner 7d on one side of the glass original plate 7 will pierce the protective sheet 8, and no catch occurs between the two 7 and 8 on that one side, which avoids the problem of the corner 7d interfering with the bending and breaking operation. Furthermore, when removing the unnecessary part 14 from the protective sheet 8 in the removal step 4, no catch occurs between the corner 14a on one side of the unnecessary part 14 (the part that was the corner on one side of the glass original plate 7) and the protective sheet 8 as shown in FIG. 7b. This prevents the unnecessary part 14 from falling off the holder, damage due to undue deformation of the unnecessary part 14, and adhesion of glass powder to the glass plate 13. As a result, inefficient interruptions of the work in the cutting step 3 and the removing step 4 are avoided, and deterioration of the quality of the glass plate 13 and the generation of defective products are suppressed. In the illustrated example, the other side 7h of the glass plate 7 and the other side 8f of the protective sheet 8 are in the same position, so that the corner 7i on the other side of the glass plate 7 and the protective sheet 8 do not get caught. This effect can also be obtained when the other side end of the glass plate 7 protrudes from the other side 8f of the protective sheet 8. Therefore, in these cases, problems that cause problems in bending the glass plate 7 and removing the unnecessary part 14 can be avoided on the other side as well.

[0044] FIG. 8 illustrates an example in which the separation step 5 is performed after the removal step 4. In the separation step, the transport conveyor 15 transports the protective sheet 8 and the glass plate 13 in the direction of the arrow D. When the two 7 and 8 reach the end 15a of the transport conveyor 15 on the front side in the transport direction, the glass plate 13 still advances in the direction of the arrow D and is transferred to the transfer unit 16 on the front side in the transport direction of the transport conveyor 15. In contrast, the protective sheet 8 is changed in its traveling direction downward by the suction force of the negative pressure. In this embodiment, the transfer unit 16 is composed of a plurality of rollers 17 arranged in a straight line in the direction of the arrow D. In addition, although the configuration for applying the suction force of the negative pressure to the protective sheet 8 is not shown, the transport roller 18 arranged at the end 15a on the front side in the transport direction of the transport conveyor 15 and its lower part apply the suction force of the negative pressure only to the protective sheet 8. Here, the "front side in the transport direction" refers to one side of the glass plate 7 in the removal step 4. In this separation step 5, the traveling directions of the glass plate 13 and the protective sheet 8 differ during the transportation in the direction of the arrow D, and thus separation of the protective sheet 8 starts from the end 13a on the front side of the transportation direction of the glass plate 13. At this time, if the corner 13b (see FIG. 7b) on the front side of the transportation direction of the glass plate 13 is stuck into the protective sheet 8, it becomes difficult to make the traveling directions of the glass plate 13 and the protective sheet 8 different. Therefore, as shown in FIG. 9, for example, the end 13a on the front side of the transportation direction of the glass plate 13 may collide with the roller 17 of the transfer unit 16 together with the protective sheet 8, and the glass plate 13 may be damaged. In this case, the corner 13b on the front side of the transportation direction of the glass plate 13 does not protrude from the missing edge 8a on the front side of the protective sheet 8, but the above-mentioned piercing is unlikely to occur because the corner 7d on one side of the glass original plate 7 protrudes from the edge 8a. As a result, the task of separating the protective sheet 8 from the glass plate 13 can be properly performed in the manner shown in FIG.

[0045] The above description of the cutting step 3 to the separation step 5 has been given with reference to the case where the glass original plate 7 and the protective sheet 8 are taken out as they are from the laminate 9 described with reference to Figs. 3a and 3b and placed on the working surface 11a of the placement unit 11 when performing the cutting step 3, but other embodiments such as those shown below can be exemplified. That is, in the first other example, when performing the cutting step 3, both the glass original plate 7 and the protective sheet 8 are taken out as they are from the laminate 9 described with reference to Figs. 4a and 4b and placed on the working surface 11a of the placement unit 11. In this way, when the glass original plate 7 is bent and broken, the corner 7i on the other side and the protective sheet 8 are less likely to get caught. Also, when the unnecessary part 14 is removed, the corner 14b (see Fig. 7b) on the other side and the protective sheet are less likely to get caught.

[0046] In the second alternative example, when cutting step 3 is performed, both the glass plate 7 and the glass plate 8 are taken out as they are from the laminate 9 described with reference to Figures 5a and 5b and placed on the work surface 11a of the placement unit 11. In this way, in the separation step 5, the corner 13b on the front side in the conveying direction of the glass plate 13 protrudes from the missing edge 8a on the front side in the conveying direction of the protective sheet 8. This reliably prevents the end 13a on the front side in the conveying direction of the glass plate 13 from piercing the protective sheet 8, so that the task of separating the protective sheet 8 from the glass plate 13 can be performed without hindrance.

[0047] In the third other example, the glass original plate 7 and the protective sheet 8 are placed on the working surface 11a of the placement unit 11 in the manner described based on Figs. 6a and 6b when performing the cutting step 3. In this manner, not only the same advantages as in the second other example are obtained when the glass original plate 7 is bent and broken, when the unnecessary portion 14 is removed, and when the protective sheet 8 is separated from the glass plate 13, but also the following advantages are obtained. That is, when performing the cutting step 3 and the removing step 4, not only the corner 7d on one side of the glass original plate 7 but also the corner 7i on the other side of the glass original plate 7 are reliably prevented from being pierced by the protective sheet 8. In this case, when the protective sheet 8 is shifted downward as described above in the manner shown in Figs. 6a and 6b, not only the edge surface along the side 7e on one side of the glass original plate 7 is protected by the protective sheet 8 during the cutting step 3 and the removing step 4, but also the edge surface along the side 7h on the other side of the glass original plate 7 is protected by the protective sheet 8. In addition, while the separation process 5 is being performed, not only is the end face of the glass plate 13 along the front side 13c in the transport direction protected by the protective sheet 8, but also the end face of the glass plate 13 along the rear side 13d in the transport direction is protected by the protective sheet 8.

[0048] Note that the protective sheet 8 according to the above embodiment is a protective sheet having a basic rectangular shape with a predetermined portion missing, or a rectangular protective sheet with a predetermined portion cut away, but the shape of the protective sheet 8 is not limited to this. For example, the protective sheet 8 may be circular, elliptical, or other polygonal by the above-mentioned missing or cut away, and even in the case of such a shape, the corners of the original glass plate 7, the corners of the product region 7b, and the corners of the glass plate 13 need to protrude in the same manner as described above.

[0049] Furthermore, although the lower side 8f of the protective sheet 8 according to the above embodiment is in contact or nearly in contact with the placement surface 10a of the packing pallet 10, it may be spaced apart from the placement surface 10a. In this case, the lower side of the protective sheet 8 has a shape in which both lower corners 7i of the original glass sheet 7 protrude, and a shape in which both lower corners 7j of the product area 7b of the original glass sheet 7 protrude. In this configuration, for example, a missing portion 8g on the lower side of the protective sheet 8 may be provided to ensure a protrusion dimension L6 of the lower corners 7j of the product area 7b from the edge 8h.

[0050] 4a and 4b and 6a and 6b, the upper cutout 8b and the lower cutout 8g are provided independently, but the upper cutout 8b and the lower cutout 8g may be connected. In other words, when the original glass plate 7 is in a vertical position, the protective sheet 8 may be provided with cutouts along the vertical direction to allow the upper corners 7d and the lower corners 7i of the original glass plate 7 to protrude. Alternatively, when the original glass plate 7 is in a vertical position, the protective sheet 8 may be provided with cutouts along the vertical direction to allow the upper corners 7g and the lower corners 7j of the product area 7b of the original glass plate 7 to protrude.

[0051] In addition, the separation step is performed after the cutting step (first cutting step) and the removing step (first removing step) according to the above embodiment, but a second cutting step and a second removing step may be provided between the first removing step and the separation step. In the second cutting step, the upper and lower ends of the glass original plate 7 in the vertical position are cut off as unnecessary parts. In the second removing step, the unnecessary parts generated in the second cutting step are removed from the protective sheet.

[0052] In the above embodiment, a single glass plate is cut out from the original glass plate, but multiple glass plates may be cut out from the original glass plate. In this case, for example, a dividing step may be provided between the removing step and the separating step, and the glass plate may be divided into multiple glass plates in the dividing step. [Explanation of symbols]

[0053] 1 Preparation process 2. Removal process 3 Cutting process 4 Removal process 5 Separation process 6 Glass plate packaging 7 Glass plate 7d Corner of one side (upper side) of glass plate 7g One side (upper) corner of the product area of ​​the glass plate 7i The other (lower) corner of the glass plate 7j The other (lower) corner of the product area of ​​the glass plate 8 Protective Sheet 8a Missing edge on one side (upper side) of protective sheet 8b Missing part on one side (upper side) of protective sheet 8g Missing part on the other side (lower side) of the protective sheet 8h Missing edge on the other side (bottom) of the protective sheet 8j The other (lower) corner of the protective sheet 9. Laminate 10 Packing pallets 13 Glass Plate 13b Corner of one side of glass plate 14 Unnecessary part 14a One corner of unnecessary part 14b: the other corner of the unnecessary part 15 Transport Conveyor

Claims

1. The glass plate is laid flat on the protective sheet, and the glass plate is cut to obtain a glass sheet. A method for manufacturing a glass plate, comprising a cutting step for separating a glass plate from an unnecessary portion, The method for manufacturing a glass plate, wherein in the cutting step, one side of the protective sheet is configured to have one corner of the original glass plate protrude from the protective sheet.

2. 2. The method for manufacturing a glass plate according to claim 1, further comprising, as a step prior to the cutting step, a preparation step of preparing a stack in which glass original plates and protective sheets are arranged alternately in a vertical position, and a removal step of removing the glass original plates and the protective sheets from the stack.

3. 3. The method for manufacturing a glass plate according to claim 2, wherein the one side is an upper side of both the original glass plate and the protective sheet when they are in the vertical position.

4. 4. The method for manufacturing a glass plate according to claim 2, wherein in the preparation step, an upper corner of the protective sheet in a vertical position is cut off to prepare the protective sheet to be used in the cutting step.

5. The method for manufacturing a glass plate according to any one of claims 1 to 4, characterized in that the shape of the one side of the protective sheet used in the cutting step is a shape in which a corner portion on one side of a product area of ​​the glass original plate protrudes from the protective sheet.

6. The method for manufacturing a glass plate according to any one of claims 1 to 5, characterized in that in the cutting step, the other side of the protective sheet is configured to have a shape in which a corner portion on the other side of the glass original plate protrudes from the protective sheet.

7. A preparation step for preparing a laminate in which glass original plates and protective sheets are alternately arranged in a vertical position, which is a step prior to the cutting step; 7. The method for manufacturing a glass plate according to claim 6, wherein the other side is the lower side of both the original glass plate and the protective sheet when they are in the vertical position.

8. The method for manufacturing a glass plate according to claim 6 or 7, characterized in that, as a step prior to the cutting step, a preparation step is provided for preparing a laminate in which glass original plates and protective sheets are arranged alternately in a vertical position, and in the preparation step, a lower corner of the protective sheet in the vertical position is cut off to produce the protective sheet to be used in the cutting step.

9. The method for manufacturing a glass plate according to any one of claims 6 to 8, characterized in that the shape of the other side of the protective sheet used in the cutting step is a shape in which a corner portion of the other side of the product area of ​​the glass original plate protrudes from the protective sheet.

10. A process subsequent to the cutting process includes a process of removing the unnecessary portion from the protective sheet, and the process subsequent to the removing process includes 10. A method for producing a glass plate, comprising: a separation step of: stacking the glass plate in place of the original glass plate in a flat position on the protective sheet used in the cutting step in the method for producing a glass plate according to any one of claims 1 to 9; transporting both of the glass plate and the original glass plate with the one side being a front side in a transport direction; and, during the transport, changing the traveling directions of the two plates to be different from each other, thereby starting separation of the protective sheet from an end of the glass plate at a front side in the transport direction, thereby separating the two plates.

11. A glass plate package in which a stack of glass original plates and protective sheets arranged alternately in a vertical position is loaded on a packaging pallet, A glass plate package, wherein the upper side of the protective sheet is configured so that the upper corners of the glass original plate protrude from the protective sheet.

Images