JP7615525B2 - Glass plate manufacturing method and glass plate package - Google Patents

Description

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

In the field of glass sheet manufacturing, glass sheets cut from glass ribbons formed by the down-draw method, float method, etc. are sometimes stacked together with protective sheets on a pallet or the like, and then both are removed and various operations are performed. As a specific example of a stack, Patent Document 1 discloses a structure in which glass sheets (glass sheets) and protective sheets are arranged alternately in a vertical position (inclined position).

Among the various operations performed on the glass original plates removed one by one together with the protective sheets from this type of laminate, there is an operation in which the orientation of both is changed from a vertical orientation to a flat orientation. For example, Patent Document 2 discloses a specific example of such an operation in which the glass original plate is placed flat on the protective sheet, 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.

In this process of cutting the glass plate on the protective sheet, both ends in the width direction of the glass plate may be cut off as unnecessary parts, and the unnecessary parts may be removed from the protective sheet after cutting. By carrying out such a process, a glass plate can be obtained as a finished product.

JP 2019-104566 A JP 2017-190255 A

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

Under such circumstances, when performing cutting work that requires bending deformation of the glass plate, such as folding work, a corner on one side of the glass plate (the upper corner of the glass plate when it is in a vertical position) may pierce the protective sheet. Therefore, when folding the glass plate along the scribe line, the corner on one side of the glass plate may get caught on the protective sheet, hindering 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 get caught on the protective sheet, causing the unnecessary part to fall off the holder. Even if the unnecessary part does not fall off the holder, the unnecessary part may be inappropriately deformed and broken due to the above-mentioned catch. In this case, glass powder may fall and adhere to the glass plate as a product, which not only reduces the quality of the glass plate but also causes defective products.

From the above perspective, the present invention aims to facilitate various operations by making it difficult for the glass original plate and the protective sheet to get caught 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.

The first aspect of the present invention, which has been invented to solve the above 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 into a glass plate and an unnecessary portion while the glass original plate is laid flat on the protective sheet after the removal step; and a removal step of removing the unnecessary portion from the protective sheet after the cutting step, wherein the shape of one side of the protective sheet is such that a corner of one side of the glass original plate protrudes from the protective sheet, and the one side is the upper side of both the glass original plate and the protective sheet when they are in the vertical position.

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 flat and the cutting process is performed. When performing this cutting process, the corners on one side of the glass original sheet protrude from the protective sheet, so that the corners on one side of the glass original sheet do not pierce 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 made smooth. In addition, in the removal process after the cutting process, the unnecessary part is lifted and removed by 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.

In the above-described method, the preparation step may involve cutting off an upper corner of the protective sheet to produce the protective sheet to be used in the cutting step.

In this way, the protective sheet in the laminate before the preparation process has its upper corners not cut off, so the protective sheet can cover the entire upper area of the glass plate. This allows the protective sheet to adequately protect the upper side of the glass plate during transport or shipping of the laminate.

In the above method, the shape of one side of the protective sheet used in the cutting process may be such that one corner of the product area of the glass original plate protrudes from the protective sheet.

In this way, after the removal process, the corner on one side of the glass plate corresponding to the product area of the glass plate still protrudes from the protective sheet. As a result, when performing work on the glass plate after the removal process, the corner on one side of the glass plate will not pierce the protective sheet, and the work after the removal process can be performed smoothly.

In this method, in the cutting process, the shape of the other side of the protective sheet is such that the corner 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.

In this way, it is possible to prevent the corners of the glass plate from piercing the protective sheet on the other side of the glass plate. This makes it possible to prevent the cutting work from becoming difficult, the unnecessary parts from falling off the holders such as suction pads and gripping members, damage due to undue deformation of the unnecessary parts, and the adhesion of glass powder to the glass plate as a finished product on the other side.

In the above-described method, the preparation step may involve cutting off a lower corner of the protective sheet to produce the protective sheet to be used in the cutting step.

In this way, the protective sheet in the laminate before the preparation process has its lower corners not cut off, so the protective sheet can cover the entire underside of the glass plate. This allows the protective sheet to adequately protect the underside of the glass plate during transport or shipping of the laminate.

In the above method, the shape of the other side of the protective sheet used in the cutting process may be such that the other corner of the product area of the glass original plate protrudes from the protective sheet.

In this way, after the removal process, the corner on the other side of the glass plate, which corresponds to the product area of the glass plate, still protrudes from the protective sheet. As a result, when performing work on the glass plate after the removal process, the corner on the other side of the glass plate will not pierce the protective sheet, and the work after the removal process can be performed smoothly.

In addition, as a step subsequent to the removal step, the method may include a separation step in which the glass plate is placed flat on top of 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 one side facing forward in the transport direction, and during the transport, the traveling directions of the two are changed to different directions, thereby starting separation of the protective sheet from the end of the glass plate facing forward in the transport direction, thereby separating the two.

In this way, the protective sheet can be separated from the glass plate 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 stuck into the protective sheet, the glass plate and the protective sheet may move in the same direction even if the traveling directions of the two are changed during the transport. 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 plate on the front side in the transport direction protrudes. In this shape, the glass plate cannot be stuck into the protective sheet. In this case, the position of the above-mentioned corner of the glass plate and the above-mentioned corner of the glass plate are merely different by the amount of the unnecessary part removed. Therefore, the above-mentioned sticking 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.

The second aspect of the present invention, which was devised to solve the above problem, is a glass plate package in which a stack of glass original plates and protective sheets 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.

With this glass plate package, the protective sheet and the glass plate can be taken out as they are, and after converting both from a vertical position to a flat position, the glass plate can be cut and unnecessary parts can be removed from the protective sheet. This prevents the corners on one side of the glass plate from piercing the protective sheet, providing the same advantages as in the above case. Furthermore, if the upper sides of the protective sheet and the glass plate are positioned at the front in the conveying direction, the protective sheet can be smoothly separated from the glass plate.

According to the present invention, when performing various operations on a glass original plate after removing 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, which facilitates the various operations.

2 is a flowchart showing a method for manufacturing a glass plate according to an embodiment of the present invention. 1 is a schematic side view showing a glass plate package according to an embodiment of the present invention. FIG. 3 is a vertical sectional front view of the glass plate package taken along line A-A in FIG. 2 . 3 is an enlarged front view showing a main part of the glass plate package cut along line A-A in FIG. 2 . FIG. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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.

Below, the glass plate manufacturing method and glass plate packaging body according to an embodiment of the present invention will be described with reference to the attached drawings.

As shown in Fig. 1, the method for manufacturing a glass plate according to this embodiment includes a preparation step 1 for preparing a stack in which glass original plates and protective sheets are arranged alternately in a vertical position on a packaging pallet, and a removal step 2 for removing the glass original plate and the protective sheet from the stack. Furthermore, this manufacturing method includes a cutting step 3 for cutting the glass original plate into a glass plate and an unnecessary portion while the glass original 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.

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 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 the down-draw method (e.g., the overflow down-draw method) or the float method, cut along the width direction. As shown in FIG. 3a, both ends 7a of the glass original sheet 7 in the width direction are unnecessary parts. These both ends 7a are separated from the product area 7b by cutting the glass original sheet 7 along the planned cutting line 7c in the cutting step 3.

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.

The configuration of the protective sheet 8 and the glass plate 7 will be described below. In the following description, the same reference numerals are used in each of the figures to designate the common components of the protective sheet 8 and the glass plate 7 shown in Figures 3a to 6b. Detailed descriptions of the components with the same reference numerals will be omitted.

The protective sheet 8 shown in FIG. 3a has an upper shape in which both upper corners 7d of the glass original 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 glass original plate 7 protrude from the missing upper edge 8a of the protective sheet 8. The protrusion dimension L1 is preferably 5 to 20 mm. In this case, the upper corners 7d of the glass original plate 7 are contained within the missing portion (the portion with parallel diagonal lines) 8b of the protective sheet 8 shown in FIG. 3b, 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 glass original plate 7, respectively. The protrusion dimension L2 from the upper side 7e is preferably 50 to 150 mm, and the protrusion 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 (the 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.

In this embodiment, in 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 and both widthwise ends of the rectangular protective sheet protrude from the upper side 7e and both widthwise sides 7f of the glass original plate 7. This results in the entire glass original plate 7 being covered by the protective sheet, and the glass original plate 7 is properly protected.

The corners of the rectangular protective sheet may be cut off during removal step 2 or after removal step 2 and before cutting step 3. This cutting work may be performed manually by an operator or by using a robot hand or the like. 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. The missing edge 8a on the upper side of the protective sheet 8 is shaped along a straight line in the illustrated example, but may also be wavy, sawtooth, arcuate, or the like.

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 glass original plate 7. In detail, 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 glass original 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 glass original 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 glass original 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 the lower corner of this protective sheet 8, the timing of chipping, 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.

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 glass original plate 7 protrude. Therefore, as shown in FIG. 5b, both the upper corners 7d of the glass original plate 7 and the upper corners 7g of the product area 7b are contained within the upper missing portion 8b of the protective sheet 8 (area with parallel diagonal lines in a dashed line) and do not reach the outer edge 8c of the missing portion 8b. It is preferable that the protruding dimension L5 of the upper corners 7g of the product area 7b is 1 to 10 mm. In this case, as shown in FIG. 5a, the lower side 8f of the protective sheet 8 contacts the mounting surface 10a and the lower side 7h of the glass original 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 glass original plate 7 may be in contact with the mounting surface 10a. Furthermore, in the illustrated example, the lower corners 8j of this protective sheet 8 are not missing, but the lower corners 8j may be missing as in the protective sheet 8 shown in Figures 4a and 4b. The method for missing the upper corners of this protective sheet 8, the timing for missing, and the shape of the edge 8a are the same as those already described for the upper corners of the protective sheet 8 shown in Figures 3a and 3b.

In addition to the upper shape, the lower shape of the protective sheet 8 shown in FIG. 6a also has a shape in which both lower corners 7j of the product area 7b of the glass original plate 7 protrude. Therefore, as shown in FIG. 6b, both the lower corners 7i of the glass original plate 7 and the lower corners 7j of the product area 7b are contained within 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. It is preferable that the protrusion dimension L6 of the lower corner 7j of the product area 7b from the edge 8h is 1 to 10 mm. Note that the lower shape of the protective sheet 8 may be a shape in which only the lower corner 7i of the glass original plate 7 protrudes. In this case, the protrusion dimension of the lower corner 7i is preferably 5 to 20 mm, and the distance dimension from the lower corner 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 Figures 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 Figures 3a and 3b. Here, the lower side 8f of the protective sheet 8 and the lower side 7h of the glass original plate 7 are at the same position or approximately the same position. In this case, in the example shown in Figures 6a and 6b, the lower side 8f of the protective sheet 8 contacts the mounting surface 10a and the lower side 7h of the glass original 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 glass original 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 glass original 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.

The removal process 2 is carried out using a device capable of holding the glass original plate 7 and the protective sheet 8 as a set, such as a device having a suction pad at its tip that suction-holds both 7 and 8, or a device having a gripping member at its tip that grips both 7 and 8. These devices then remove the glass original plate 7 and the protective sheet 8 from the stack 9, and change their positions so that the glass original plate 7 is laid flat on top of the protective sheet 8.

7a and 7b are perspective views illustrating the manner in which the cutting step 3 is 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 original glass plate 7 are in the same position or approximately the same position, but may be the same as the embodiment already described with reference to Fig. 3a. That is, the end portion including the other side 8f of the protective sheet 8 may extend beyond the other side 7h of the original glass plate 7, or the end portion including the other side 7h of the original glass plate 7 may extend beyond the other side 8f of the protective sheet 8.

Figure 7a illustrates an example of forming a scribe line along the planned cutting line 7c on the surface (upper surface) of the glass original plate 7. In this embodiment, the scribe wheel 12 is moved along the planned cutting line 7c of the glass original 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 glass original plate 7 from the other side to one side. The scribe line 7k may be formed in a portion excluding the end on the other side and the end on one side of the glass original plate 7. After that, a bending stress is applied to the formation area of the scribe line 7k of the glass original plate 7 to bend and break the glass original plate 7 along the scribe line 7k, thereby dividing the glass original plate 7 into a glass plate (glass plate as product) 13 and an unnecessary portion 14 as shown in Figure 7b.

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

The effects of performing the cutting step 3 and the removing step 4 are as follows. That is, in the cutting step 3, as shown in FIG. 7a, the corner 7g on one side 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, the end on one side of the planned cutting line 7c is supported by the protective sheet 8 from below. Moreover, in the illustrated example, the end on the other side of the planned cutting line 7c is also supported by the protective sheet 8 from below. 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 is possible to accurately form the scribe line 7k. This effect can also be obtained when the end on the other side of the protective sheet 8 protrudes from the other side 7h of the glass original plate 7. In addition, in the case where the other end of the glass original plate 7 protrudes from the other side 8f of the protective sheet 8, a similar effect can be obtained by forming a scribe line 7k in an area excluding the other end and one end of the glass original plate 7.

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, 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 side, which avoids the problem of it interfering with the bending and breaking work. Furthermore, when removing the unnecessary part 14 from the protective sheet 8 in the removal process 4, as shown in FIG. 7b, 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. This avoids the unnecessary part 14 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 original plate 7 and the other side 8f of the protective sheet 8 are in the same position, so that no catch occurs between the other side corner 7i of the glass original plate 7 and the protective sheet 8. This effect can also be obtained when the other side end of the glass original plate 7 protrudes from the other side side 8f of the protective sheet 8. Therefore, in these cases, problems that cause problems in bending the glass original plate 7 and removing the unnecessary part 14 can be avoided on the other side as well.

Figure 8 illustrates an example of the separation process 5 being performed after the removal process 4. In the separation process, the transport conveyor 15 transports the protective sheet 8 and the glass plate 13 in the direction of the arrow D. When both 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 section 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 section 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 original plate 7 in the removal process 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, so that 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 operation of separating the protective sheet 8 from the glass plate 13 can be properly performed in the manner shown in FIG.

The above explanation of the cutting process 3 to the separation process 5 has been given as an example of the case where the glass original plate 7 and the protective sheet 8 are taken out as they are from the laminate 9 described based on Figures 3a and 3b when performing the cutting process 3 and placed on the work surface 11a of the placement unit 11, but other examples can be given as shown below. That is, in the first other example, when performing the cutting process 3, both 7 and 8 are taken out as they are from the laminate 9 described based on Figures 4a and 4b and placed on the work surface 11a of the placement unit 11. In this way, it becomes even more difficult for the corner 7i on the other side and the protective sheet 8 to get caught when the glass original plate 7 is bent and broken. In addition, it becomes even more difficult for the corner 14b on the other side (see Figure 7b) and the protective sheet to get caught when removing the unnecessary part 14.

In the second alternative example, when performing cutting step 3, both 7 and 8 are taken out as they are from the laminate 9 described based on Figures 5a and 5b and placed on the work surface 11a of the placement unit 11. In this way, in 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.

In the third other example, the glass original plate 7 and the protective sheet 8 are placed on the work surface 11a of the placement unit 11 in the manner described based on Figures 6a and 6b when performing the cutting process 3. In this way, when the glass original plate 7 is bent and broken, when the unnecessary part 14 is removed, and when the protective sheet 8 is separated from the glass plate 13, not only the same advantages as those in the second other example are obtained, but also the following advantages are obtained. That is, when performing the cutting process 3 and the removal process 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 Figures 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 process 3 and the removal process 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 along the front edge 13c of the glass plate 13 in the transport direction protected by the protective sheet 8, but the end face along the rear edge 13d of the glass plate 13 in the transport direction is also protected by the protective sheet 8.

The protective sheet 8 according to the above embodiment is a rectangular protective sheet with a basic shape in which a specific portion is missing, or a rectangular protective sheet with a specific portion cut out, 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 due to the missing or cut out portions, and even in the case of such a shape, the corners of the glass original plate 7, the corners of the product area 7b, and the corners of the glass plate 13 must protrude in the same manner as described above.

In addition, the lower edge 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, but may be spaced apart from the placement surface 10a. In this case, the lower side of the protective sheet 8 has a shape that protrudes both lower corners 7i of the glass original plate 7 and a shape that protrudes both lower corners 7j of the product area 7b of the glass original plate 7. In this configuration, for example, a missing portion 8g on the lower side of the protective sheet 8 may be provided to ensure the protrusion dimension L6 of the lower corners 7j of the product area 7b from the edge 8h.

In addition, in the protective sheet 8 according to Figures 4a and 4b and Figures 6a and 6b, the upper missing portion 8b and the lower missing portion 8g are provided independently, but the upper missing portion 8b and the lower missing portion 8g may be connected. In other words, when the glass original plate 7 is in a vertical position, the protective sheet 8 may be provided with missing portions along the vertical direction so that the upper corners 7d and the lower corners 7i of the glass original plate 7 can protrude. Alternatively, when the glass original plate 7 is in a vertical position, the protective sheet 8 may be provided with missing portions along the vertical direction so that the upper corners 7g and the lower corners 7j of the product area 7b of the glass original plate 7 can protrude.

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

In the above embodiment, a single glass plate is cut out from the glass plate, but multiple glass plates may be cut out from the glass plate. In this case, for example, a division process may be provided between the removal process and the separation process, and the glass plate may be divided into multiple glass plates in the division process.

1 Preparation process 2 Removal process 3 Cutting process 4 Removal process 5 Separation process 6 Glass plate package 7 Glass plate 7d Corner 7g on one side (upper side) of glass plate Corner 7i on one side (upper side) of product area of glass plate Corner 7j on the other side (lower side) of product area of glass plate Protective sheet 8a Missing edge 8b on one side (upper side) of protective sheet Missing portion 8g on one side (upper side) of protective sheet Missing portion 8h on the other side (lower side) of protective sheet Missing edge 8j on the other side (lower side) of protective sheet Corner 9 on the other side (lower side) of protective sheet Stack 10 Packaging pallet 13 Glass plate 13b Corner 14 on one side of glass plate Unnecessary portion 14a Corner 14b on one side of unnecessary portion Corner 15 on the other side of unnecessary portion

Claims (11)

A method for manufacturing a glass plate, comprising: a cutting step of cutting an original glass plate in a state where the original glass plate is laid flat on a protective sheet to separate the original 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. 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. The method for manufacturing a glass plate according to claim 2, characterized in that the one side is the upper side of both the glass plate and the protective sheet when they are in the vertical position. The method for manufacturing a glass plate according to claim 2 or 3, characterized in that in the preparation step, the upper corners of the protective sheet in a vertical position are cut off to produce the protective sheet to be used in the cutting step. 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 process is such that one corner of the product area of the glass plate protrudes from the protective sheet. The method for manufacturing a glass plate according to any one of claims 1 to 5, characterized in that in the cutting step, the shape of the other side of the protective sheet is such that the corner of the other side of the glass original plate protrudes from the protective sheet. A preparation step is provided prior to the cutting step, in which a laminate in which glass original plates and protective sheets are alternately arranged in a vertical position is prepared,
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. The method for manufacturing a glass plate according to claim 6 or 7, further comprising a preparation step, prior to the cutting step, of 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. 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 process is such that the corner of the other side of the product area of the glass plate protrudes from the protective sheet. 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 transporting both of the glass plate and the protective sheet used in the cutting step in a state in which the glass plate is placed flat on the protective sheet used in the cutting step instead of the original glass plate, with the one side being a front side in a transport direction, and by changing the traveling directions of the two plates during the transport, separation of the protective sheet is started from an end of the glass plate at a front side in the transport direction, thereby separating the two plates. 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.

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