JP7092018B2 - Glass plate manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a glass plate, and more particularly to a method for cutting a glass plate from a glass ribbon formed by a down draw method.

As is well known, a method for manufacturing a glass plate using a downdraw method (for example, an overflow downdraw method) includes a molding step of molding a glass ribbon and a cutting step of cutting out a glass plate from the molded glass ribbon. There is.

As a specific example, in Patent Document 1, a cooling roller (plate pulling roller) that cools the widthwise end of the glass ribbon immediately below the molded body and a glass ribbon that is arranged below the cooling roller and is fed downward. It is disclosed that a molding process is performed using a plurality of transport rollers (annealing rollers and support rollers). Further, Patent Document 1 also discloses a cutting process for cutting out a short glass plate by engraving a scribe line on a glass ribbon at a position below a plurality of transport rollers and folding the glass ribbon along the scribe line. Has been done.

On the other hand, in Patent Document 1 (FIG. 4, etc. of the same document), when performing the cutting process, a scribe line is formed on the widthwise end of the glass ribbon (the ear portion thicker than the widthwise central portion) with a scribing tip. It is disclosed that it will be engraved. More specifically, the document discloses that the end point of the scribe line is located at the widthwise end on one side of the glass ribbon. The widthwise end of the glass ribbon corresponds to a contact portion with the cooling roller (see FIG. 1 of the same document).

Further, in Patent Document 1 (FIG. 1 of the same document), when the molding process is performed, the contact portion of the glass ribbon with the cooling roller and the contact portion with the transport roller overlap in the width direction. It has been disclosed.

Japanese Unexamined Patent Publication No. 2018-90448

Generally, the contact portion of the glass ribbon formed by the down draw method with the cooling roller has insufficient strength. Therefore, if the start point and the end point of the scribe line are positioned at this contact portion, vertical cracks (cracks along the length direction of the glass ribbon) may occur in the glass ribbon starting from this contact portion. From the viewpoint of preventing the occurrence of vertical cracks, the engraved position of the scribe line disclosed in Patent Document 1 is not preferable.

Further, in order to prevent the occurrence of vertical cracks, it is assumed that the start point and the end point of the scribe line are positioned on the center side in the width direction of both the contact portion of the glass ribbon with the cooling roller and the contact portion with the transport roller. , The widthwise dimension of the part where the scribe line is not formed becomes long. Therefore, when this glass ribbon is folded along the scribe line, there arises a problem that a large amount of glass powder is scattered.

Further, the surface of the contact portion of the glass ribbon formed by the down draw method with the cooling roller is not smooth as compared with the portion on the center side in the width direction of the glass ribbon. Therefore, as disclosed in Patent Document 1, when the contact portion with the cooling roller and the contact portion with the transport roller overlap in the width direction of the glass ribbon, the surface of the transport roller comes into contact with the cooling roller. Contact the non-smooth surface of the part. Under this condition, unevenness due to wear may be formed on the surface of the transport roller with the use over time. If glass powder enters the recesses on the surface of the transport roller, the contact portion with the transport roller may be scratched, resulting in a decrease in the strength of the contact portion. Therefore, while the glass ribbon is being fed downward, vertical cracks are likely to occur in the glass ribbon starting from this contact portion.

From the above viewpoint, the present invention is for folding the glass ribbon along the scribing line while suppressing the situation where the glass ribbon is vertically cracked before the glass ribbon is formed and the glass plate is cut out. The challenge is to reduce the amount of glass powder scattered.

The present invention, which was devised to solve the above problems, includes a molding step of molding a glass ribbon by a downdraw method and a cutting step of cutting out a glass plate from the molded glass ribbon. In the molding step, a cooling roller is provided. A process of cooling the end portion of the glass ribbon in the width direction and a process of feeding the glass ribbon downward by a transport roller arranged below the cooling roller are performed, and the glass ribbon is fed downward in the cutting step. A method for manufacturing a glass plate, in which a process of engraving a scrib line on a glass ribbon at a position below the transfer roller and a process of breaking the glass ribbon along the scrib line are performed, and the transfer of the glass ribbon is performed. The contact portion with the roller is positioned on the center side in the width direction with respect to the contact portion with the cooling roller, and the start point and the end point of the scrib line are set at the contact portion between the contact portion with the transport roller of the glass ribbon and the cooling roller. It is characterized by being positioned between and. Here, the above-mentioned "contact portion" is not limited to the portion where the cooling roller and the transport roller are in contact with the glass ribbon, respectively, and also includes a portion where the contact mark is formed (hereinafter, the same applies).

According to such a configuration, the contact portion of the glass ribbon with the transport roller and the contact portion with the cooling roller do not overlap in the width direction. Therefore, even if the surface of the contact portion with the cooling roller is not smooth, the surface of the transport roller does not come into contact with the uneven surface. As a result, unevenness due to wear is not formed on the surface of the transport roller, and a decrease in strength of the contact portion with the transport roller is suppressed. As a result, it is possible to prevent a situation in which vertical cracks occur in the glass ribbon starting from the contact portion with the transport roller when the transport roller feeds the glass ribbon in the molding process. Moreover, the scribe wire does not reach the contact portion with the cooling roller. Therefore, the contact portion with the cooling roller is less likely to be affected by engraving the scribe wire. As a result, it is possible to prevent a situation in which vertical cracks occur in the glass ribbon starting from the contact portion with the cooling roller when engraving the scribe wire in the cutting process. In addition, the scribe line passes (crosses) the contact portion with the transport roller. Therefore, it is possible to shorten the widthwise dimension of the portion where the scribe line is not formed on the glass ribbon. As a result, it is possible to reduce the amount of glass powder scattered when the glass ribbon is folded along the scribe line in the cutting process.

In this method, when the strength of the contact portion of the glass ribbon with the transport roller is reduced, the positions of the start point and the end point of the scribe line are changed to the positions on the center side in the width direction with respect to the contact portion. May be good.

By doing so, by changing the positions of the start point and the end point of the scribe line, the scribe line does not interfere with the contact portion with the transport roller. Therefore, even if the strength of the contact portion of the glass ribbon with the transport roller is reduced due to the transport roller feeding the glass ribbon in the molding process, the glass ribbon is damaged starting from the contact portion with the transport roller. It is possible to surely deter the situation that occurs. For example, the surface of the transport roller becomes scratched and fluffy due to contact with the glass ribbon as it is used over time, and glass powder adheres to the surface. Therefore, the strength of the contact portion is lowered due to scratches on the contact portion with the transport roller. In such a state, if the scribe wire passes through the contact portion with the transport roller as described above, the glass ribbon may be damaged starting from the contact portion. In the present invention, in such a case, the engraving position of the scribe wire is changed so that the scribe wire does not interfere with the contact portion with the conveying roller.

Further, in this method, when the strength of the contact portion of the glass ribbon with the transport roller is restored, the positions of the start point and the end point of the scribe line are set between the contact portion of the glass ribbon with the cooling roller and the transport roller. It may be returned to the position between the contact portion of the.

By doing so, the positions of the start point and the end point of the once changed scribe line are returned to the original positions. As a result, when the glass ribbon is folded in the cutting process while suppressing the situation where the glass ribbon is vertically cracked starting from the contact portion with the transport roller and the contact portion with the cooling roller in the molding process and the cutting process. The amount of glass powder scattered can be reduced. In this case, as a method for recovering the strength of the contact portion with the transfer roller, for example, the transfer roller may be replaced.

According to the present invention, the glass powder when the glass ribbon is folded along the scrib line while suppressing the situation where the glass ribbon is vertically cracked before the glass ribbon is formed and the glass plate is cut out. The amount of scattering can be reduced.

It is a schematic diagram which shows the main process of the manufacturing method of the glass plate which concerns on embodiment of this invention. It is a front view which shows the schematic structure of the manufacturing apparatus used for carrying out the manufacturing method of the glass plate which concerns on embodiment of this invention. It is a longitudinal side surface which shows the schematic structure of the manufacturing apparatus used for carrying out the manufacturing method of the glass plate which concerns on embodiment of this invention. It is an enlarged cross-sectional plan view of the main part of the glass ribbon which shows one state which carries out the cutting process of the manufacturing method of the glass plate which concerns on embodiment of this invention. It is an enlarged cross-sectional plan view of the main part of the glass ribbon which shows the other state which carries out the cutting process of the manufacturing method of the glass plate which concerns on embodiment of this invention. It is a front view which shows the schematic structure of the manufacturing apparatus after the manufacturing method of the glass plate which concerns on embodiment of this invention is carried out. It is a front view which shows the schematic structure of the manufacturing apparatus used for carrying out the manufacturing method of the glass plate which concerns on embodiment of this invention.

Hereinafter, a method for manufacturing a glass plate according to an embodiment of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 1, the methods for manufacturing a glass plate according to the present embodiment are roughly classified into a molding step A1 for molding a glass ribbon by an overflow downdraw method and a cutting step for cutting out a glass plate from the molded glass ribbon. It is equipped with A2. In the molding step A1, an end cooling process for cooling the widthwise end of the glass ribbon and a transport process for feeding the glass ribbon downward are performed. Further, in the cutting step A2, a scribe process for engraving a scribe line on the glass ribbon and a folding process for folding the glass ribbon along the scribe line are performed.

2 and 3 illustrate the glass plate manufacturing apparatus 1 used for performing the molding step A1 and the cutting step A2. As shown in each of these figures, the glass plate manufacturing apparatus 1 is arranged directly below the molded body 2 to cool the widthwise end of the glass ribbon G, and below the cooling roller 3. It has a transport roller 4 that feeds the glass ribbon G downward. Further, the manufacturing apparatus 1 has a scribe chip 5 for engraving a scribe line S at a position below the transport roller 4 on a glass ribbon G sent downward, and glass along the engraved scribe line S. It has a folding device 6 for folding the ribbon G.

The cooling roller 3 is a cantilever roller arranged in the internal space of the molding furnace together with the molded body 2. In the front view shown in FIG. 2, a pair of cooling rollers 3 are provided on the left and right sides, and in the side view shown in FIG. 3, the cooling rollers 3 sandwich the glass ribbon G from both front and rear sides. The transfer rollers 4 are arranged in, for example, a plurality of upper and lower stages (one stage in the figure) in the internal space (including the cooling zone) of the annealing furnace. In the side view shown in FIG. 2, the transport rollers 4 are mounted on the left and right sides of the roller shaft 4x, and in the side view shown in FIG. 3, the transport rollers 4 sandwich the glass ribbon G from both the front and rear sides. When the transport rollers 4 are arranged in a plurality of upper and lower stages, a scribe line S is engraved on the glass ribbon G at a position below the lowermost transport roller 4. Further, the glass ribbon G does not have to be sandwiched by the transport rollers 4 in all stages, and may be sandwiched by at least one transport roller 4.

Hereinafter, a method for manufacturing a glass plate according to the present embodiment will be described in detail.

As shown in FIG. 2, in the molding step A1, the transport roller 4 is positioned on the center side in the width direction with respect to the cooling roller 3. In addition, in the molding step A1, the contact portion G1 of the glass ribbon G with the transport roller 4 (hereinafter referred to as the first contact portion G1) is referred to as the contact portion G2 with the cooling roller 3 (hereinafter referred to as the second contact portion G2). It is located on the center side in the width direction. FIG. 2 shows the first contact portion G1 as a streak-like region with relatively large pitch cross-hatching, and the second contact portion G2 is shown as a streak with relatively small pitch cross-hatching. It is illustrated as a shaped area. In this case, unlike the example, even if the transport roller 4 and the cooling roller 3 overlap in the width direction, the first contact portion G1 and the second contact portion G2 do not overlap in the width direction. good.

A scribe line S is engraved on the glass ribbon G formed in the forming step A1 in the cutting step A2. Specifically, since the glass ribbon G is fed downward, the scribe chip 5 is moved diagonally downward with respect to the width direction on the front surface side of the glass ribbon G. As a result, as shown in the figure, a linear scribe line S along the width direction (horizontal direction) is engraved on the glass ribbon G. On the rear surface side of the glass ribbon G, a member corresponding to a surface plate that receives the pressing force of the scribe chip 5, a support roller that moves in synchronization with the scribe chip 5, and the like (not shown) are arranged.

Both the start point S1 and the end point S2 of the scribe line S engraved on the glass ribbon G are located between the first contact portion G1 and the second contact portion G2. Therefore, the scribe line S passes through (crosses) the first contact portion G1, but does not reach the second contact portion G2. The second contact portion G2 can be visually recognized because the surface is not smooth and irregularities are formed, but the first contact portion G1 may or may not be visible.

FIG. 4 is a cross-sectional plan view (a diagram omitting hatching) showing a main part of the glass ribbon G on which the scribe line S is engraved by the scribe chip 5. In the present embodiment, a scribing tool is used as the scribe tip 5, but a scribe wheel or the like may be used instead of the scribing tool. As shown in the figure, the widthwise end portion Gx of the glass ribbon G is thicker than the widthwise center side portion Gy. The plate thickness of the portion Gy closer to the center in the width direction of the glass ribbon G is the same as that in the center in the width direction, and the plate thickness is uniform over the entire length. A plate thickness changing portion Gz is formed between the widthwise end portion Gx of the glass ribbon G and the widthwise central side portion Gy so that the plate thickness gradually decreases as the glass ribbon G shifts to the widthwise central side.

In the illustrated example, the first contact portion G1 is located at the portion Gy closer to the center in the width direction of the glass ribbon G. The second contact portion G2 is a portion of the glass ribbon G at the widthwise end portion Gx where the cooling roller 3 comes into contact. Further, in the illustrated example, the start point S1 and the end point S2 of the scribe line S are located at the widthwise center side portion Gy of the glass ribbon G.

The widthwise separation dimension L1 from the start point S1 and the end point S2 of the scribe line S to the first contact portion G1 is preferably 10 mm or more, and from the start point S1 and the end point S2 of the scribe line S to the second contact portion G2. The widthwise separation dimension L2 is preferably 10 mm or more. If the dimension L1 is less than 10 mm, the widthwise dimension of the portion where the scribe line S is not formed on the glass ribbon G becomes too long, and a large amount of glass powder is scattered when folding. On the other hand, if the dimension L2 is less than 10 mm, the start point S1 and the end point S2 of the scribe line S come too close to the second contact portion G2, and the second contact portion G2 is used as the starting point when engraving the scribe line S. Vertical cracks may occur in the glass ribbon G. Therefore, if the dimensions L1 and L2 are within the numerical range, these problems can be avoided.

As shown in FIG. 5, the start point S1 and the end point S2 of the scribe line S may be positioned at the plate thickness change portion Gz of the glass ribbon G, but in this case, the plate thickness of the plate thickness change portion Gz varies. Since it is easy to do so, the scribe chip 5 is consumed due to the fluctuation of the depth of the scribe line S, and the life of the scribe chip 5 is shortened. From the viewpoint of preventing this, it is preferable to position the start point S1 and the end point S2 of the scribe line S at the widthwise center side portion Gy of the glass ribbon G.

In the cutting step A2, after the scribe line S is engraved, the glass ribbon G is folded along the scribe line S by the folding device 6, and the glass plate GP is cut out as shown in FIG. The folding device 6 may be configured to perform folding by bending the glass ribbon G, or the folding device 6 may be folded by pushing the engraved portion of the scribe line S from the rear surface side with a thrusting tool (for example, a blade). It may be configured to perform the above.

According to the above-mentioned method for manufacturing a glass plate according to the present embodiment, the following effects are obtained. The first contact portion G1 and the second contact portion G2 of the glass ribbon G do not overlap in the width direction. Therefore, the surface of the transport roller 4 is not affected by the unevenness of the second contact portion G2. As a result, problems such as glass powder getting into the surface of the transport roller 4 do not occur, and a decrease in the strength of the first contact portion G1 is suppressed. As a result, it is possible to prevent a situation in which vertical cracks occur in the glass ribbon G starting from the first contact portion G1 when the transport roller 4 feeds the glass ribbon G in the molding step A1.

Further, the second contact portion G2 of the glass ribbon G has low strength because the surface is formed with irregularities. However, the scribe line S has not reached the second contact portion G2. Therefore, the second contact portion G2 is not easily affected by engraving the scribe line S. As a result, it is possible to prevent a situation in which vertical cracks occur in the glass ribbon G starting from the second contact portion G2 when the scribe line S is engraved in the cutting step A2. On the other hand, the scribe line S passes through the first contact portion G1. Therefore, the widthwise dimension of the portion where the scribe line S is not formed on the glass ribbon G can be shortened. As a result, it is possible to reduce the amount of glass powder scattered when the glass ribbon G is broken along the scribe line S in the cutting step A2.

In the method for manufacturing a glass plate according to the present embodiment, in addition to the treatment as described above, the treatment as shown below is also performed.

While the cutting step A2 is repeatedly performed on the glass ribbon G molded in the molding step A1, the strength of the first contact portion G1 of the glass ribbon G may decrease. This is because the surface of the transport roller 4 becomes fluffy due to the occurrence of contact scratches and the like as it is used over time, and glass powder adheres to it. By making a scratch or the like on the contact portion G1. As a result of the strength of the first contact portion G1 of the glass ribbon G being lowered, the glass ribbon G may be damaged. When this kind of strength decrease or breakage occurs, as shown in FIG. 7, the positions of the start point S1 and the end point S2 of the scribe line S engraved on the glass ribbon G are wider than the first contact portion G1. Change to the position on the center side of the direction. In this case, the widthwise separation dimension L3 from the start point S1 and the end point S2 of the scribe line S to the first contact portion G1 is preferably 10 to 100 mm. By doing so, the scrib line S engraved on the glass ribbon G does not interfere with the first contact portion G1, so that the situation where the glass ribbon G is damaged starting from the first contact portion G1 is surely suppressed. can do.

Further, while the cutting step A2 is performed in such a state, the strength of the first contact portion G1 of the glass ribbon G is such that the glass ribbon G starting from the first contact portion G1 is not damaged. May recover. As a method for recovering the strength of the first contact portion G1, for example, the transfer roller 4 may be replaced. Then, in such a case, the positions of the start point S1 and the end point S2 of the scribe line S are returned to the positions described with reference to FIG. 4 or FIG. By doing so, the amount of glass powder scattered when folding is reduced while suppressing the situation where the glass ribbon G is damaged from the first contact portion G1 and the second contact portion G2 as the starting point. can do.

In the above embodiment, the glass ribbon G is molded by using the overflow downdraw method in the molding step A1, but the glass ribbon G is molded by using another downdraw method such as the slot downdraw method. You may do so.

1 Glass plate manufacturing equipment 3 Cooling roller 4 Conveying roller A1 Molding process A2 Cutting process G Glass ribbon G1 Contact part with transfer roller (first contact part)
Contact part with G2 cooling roller (second contact part)
GP glass plate Gx glass ribbon widthwise end S scribe line S1 scribe line start point S2 scribe line end point

Claims (3)

It includes a molding process of molding a glass ribbon by the down draw method and a cutting process of cutting out a glass plate from the molded glass ribbon.
In the molding step, a process of cooling the widthwise end portion of the glass ribbon by the cooling roller and a process of feeding the glass ribbon downward by the transport roller arranged below the cooling roller are performed.
In the cutting step, a process of engraving a scribe line on the glass ribbon sent downward at a position below the transfer roller and a process of breaking the glass ribbon along the scribe line are performed on the glass plate. It ’s a manufacturing method,
The contact portion of the glass ribbon with the transport roller is positioned on the center side in the width direction with respect to the contact portion with the cooling roller.
A method for manufacturing a glass plate, characterized in that the start point and the end point of the scribe wire are positioned between a contact portion of the glass ribbon with the transport roller and a contact portion with the cooling roller. In the method for manufacturing a glass plate according to claim 1, when the strength of the contact portion of the glass ribbon with the transport roller is reduced, the positions of the start point and the end point of the scribe line are centered in the width direction with respect to the contact portion. A method for manufacturing a glass plate, which comprises changing to a side position. In the method for manufacturing a glass plate according to claim 2, when the strength of the contact portion of the glass ribbon with the transport roller is restored, the positions of the start point and the end point of the scrib line are set with the cooling roller of the glass ribbon. A method for manufacturing a glass plate, which comprises returning the glass plate to a position between the contact portion and the contact portion between the transfer roller.

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