Apparatus for manufacturing glass plates and method for manufacturing glass plates

Abstract

To accurately measure the movement speed of a glass ribbon without damaging it or causing slippage between the glass ribbon and the user. [Solution] The glass plate manufacturing apparatus 1 comprises a molding apparatus 2 for forming a glass ribbon R, a conveying apparatus 3 for conveying the glass ribbon R downward, a speed measuring apparatus 4 for measuring the movement speed of the glass ribbon R being conveyed downward, and a cutting apparatus 5 for cutting out a single sheet of glass plate Gp from the glass ribbon R. The speed measuring apparatus 4 measures the movement speed of the glass ribbon R non-contact.

Description

Technical Field

[0001] The present invention relates to a glass plate manufacturing technique having a configuration for measuring the moving speed of a glass ribbon.

Background Art

[0002] In the field of glass plate manufacturing, a technique is known in which a glass ribbon is formed by the down-draw method and a sheet-like glass plate is cut out from the formed glass ribbon.

[0003] In this technique, in order to reduce variations and distortions in the thickness of the glass ribbon, it is necessary to accurately measure the moving speed of the glass ribbon.

[0004] As a method for measuring the moving speed of a glass ribbon, for example, according to Patent Document 1, it is disclosed that the moving speed of the glass ribbon is calculated based on the rotational speed of a pulling roller that pulls the glass ribbon downward.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the technique disclosed in Patent Document 1 measures the moving speed of a glass ribbon using a pulling roller that rotates in contact with the glass ribbon. When such contact-type speed measurement means is used, there is a risk that the glass ribbon may be damaged starting from the contact portion.

[0007] Furthermore, in the method disclosed in the same document, slippage can inevitably occur between the traction roller and the glass ribbon during the process of the traction roller rotating in contact with the glass ribbon. Therefore, it is difficult to accurately measure the moving speed of the glass ribbon.

[0008] From the above perspective, the object of the present invention is to accurately measure the movement speed of a glass ribbon without damaging the glass ribbon and without causing slippage between the glass ribbon and the device. [Means for solving the problem]

[0009] (1) The first aspect of the present invention, which was devised to solve the above problems, is a glass plate manufacturing apparatus comprising: a molding apparatus for forming a glass ribbon from molten glass; a conveying apparatus for conveying the glass ribbon downward; a speed measuring apparatus for measuring the moving speed of the glass ribbon conveyed downward by the conveying apparatus; and a cutting apparatus for cutting out a single sheet of glass plate from the glass ribbon, wherein the speed measuring apparatus measures the moving speed of the glass ribbon in a non-contact manner.

[0010] With this configuration, the speed measuring device can measure the movement speed of the glass ribbon without contacting the glass ribbon. This makes it possible to accurately measure the movement speed of the glass ribbon without damaging it or causing slippage between the device and the glass ribbon.

[0011] (2) In the configuration of (1) above, the cutting device comprises a scribe device that forms a scribe line on the glass ribbon along the width direction perpendicular to the transport direction of the glass ribbon, and a folding device that breaks the glass ribbon at the position where the scribe line is formed to obtain a single sheet of glass, and the speed measuring device comprises a plurality of sensors positioned below the position where the folding device breaks the glass ribbon and capable of detecting the presence or absence of the glass ribbon, the plurality of sensors being positioned at different positions in the vertical direction, and the moving speed of the glass ribbon may be calculated using the time at which each of the plurality of sensors detects the position of the lower end surface of the glass ribbon formed by the folding device, and the vertical distance between each of the plurality of sensors.

[0012] Here, since the glass ribbon is a transparent material that is continuously molded, non-contact speed measurement using optical means is difficult. However, the position of the lower end surface (cut end surface) of the glass ribbon can be easily detected non-contact using a sensor capable of detecting the presence or absence of the glass ribbon. Therefore, by placing multiple sensors at different positions in the vertical direction, the movement speed of the glass ribbon can be accurately measured by a simple calculation using time and distance.

[0013] (3) In the configuration of (1) or (2) above, the glass ribbon has tabs at both ends in the width direction perpendicular to the transport direction of the glass ribbon, which are thicker than the central part in the width direction, and the speed measuring device may measure the moving speed of the area of ​​the glass ribbon that is closer to the center in the width direction than the tabs.

[0014] In this case, the lugs have a large amount of residual stress, and may break or fall off during measurement. Therefore, even if the movement speed of the lugs is measured, the movement speed of the glass ribbon cannot be accurately measured. With this configuration, the movement speed of the region on the central side in the width direction is measured rather than the lugs, so the movement speed of the glass ribbon can be accurately measured.

[0015] (4) In any of the configurations described in (1) to (3) above, the speed measuring device may measure the speed of movement in the region between the start and end of the scribed line in the glass ribbon.

[0016] In this configuration, the region on the widthwise end side of the scribe line is not folded along the scribe line, making the cut end face (bottom end face) of the glass ribbon prone to damage. Therefore, after the cut end face is detected by the relatively upper sensor, but before it is detected by the relatively lower sensor, new chips or defects may occur on the cut end face in that end-side region. As a result, the movement speed of the glass ribbon cannot be accurately measured in that end-side region. With this configuration, the cut end face becomes the end face that is folded along the scribe line, thus avoiding such problems.

[0017] (5) In any of the configurations (1) to (4) above, the scribe device may form a scribe line from one end to the other in the width direction of the glass ribbon, and the speed measuring device may measure the moving speed of the region on one end side of the center in the width direction of the glass ribbon.

[0018] In this configuration, the scribed line is formed by the scriber from one end of the glass ribbon in the width direction to the other end, so that the other end of the glass ribbon becomes the end of the scribed line. In this case, wrinkles are likely to occur in the region of the glass ribbon at the end of the scribed line during its formation. Therefore, in this configuration, the speed measuring device measures the movement speed of the region of the glass ribbon excluding the region at the end of the scribed line, that is, the region on one end of the glass ribbon from the center in the width direction. As a result, the speed measuring device can measure the movement speed of the glass ribbon in a region where wrinkles are less likely to occur, enabling accurate measurement of the movement speed.

[0019] (6) In any of the configurations (1) to (5) above, the cutting device may move downward following the moving speed of the glass ribbon measured by the speed measuring device.

[0020] Here, it is conceivable to make the downward moving speed of the cutting device follow the conveying speed of the glass ribbon by the conveying device. However, slippage is inevitably likely to occur between the roller provided in the conveying device and the glass ribbon. Therefore, it is difficult to accurately match the moving speed of the glass ribbon and the moving speed of the cutting device. According to the configuration here, since the moving speed of the cutting device is made to follow the moving speed measured by the speed measuring device, the moving speed of the glass ribbon and the moving speed of the cutting device can be more accurately matched.

[0021] (7) In any of the configurations (1) to (6) above, the plurality of sensors may be a transmissive laser sensor, a reflective laser sensor, an ultrasonic sensor, or a thermography.

[0022] In such a case, if the plurality of sensors are transmissive laser sensors, even when the glass ribbon shakes, the presence or absence of the glass ribbon can be accurately detected. Also, if the plurality of sensors are reflective laser sensors or ultrasonic sensors, even for a glass ribbon that is a transparent body, the presence or absence of the glass ribbon can be accurately detected. Further, if the plurality of sensors are thermography, even if the transparent glass ribbon shakes, the presence or absence of the glass ribbon can be accurately detected.

[0023] (8) In any of the configurations (1) to (7) above, the plurality of sensors may be arranged at the same position in the width direction.

[0024] If it is done in this way, when cracks or chips occur on the lower end surface of the glass ribbon or the lower end surface is cut obliquely, that is, when the lower end surface of the glass ribbon does not extend linearly along the horizontal direction, the moving speed of the glass ribbon can be accurately measured.

[0025] (9) In any of the configurations (1) to (8) above, the cutting device includes a support portion that supports a cutting target portion that is a target for cutting out a sheet-like glass plate in the glass ribbon. The support portion changes the posture of the cutting target portion from a vertical posture to an inclined posture, thereby applying bending stress to the scribing line formation position to cut out the cutting target portion from the glass ribbon. The plurality of sensors may be arranged to detect the position of the lower end surface of the glass ribbon before the support portion changes the posture of the cutting target portion from a vertical posture to an inclined posture.

[0026] Here, when the support portion of the cutting device changes the posture of the cutting target portion of the glass ribbon from a vertical posture to an inclined posture, the position of the lower end surface of the cutting target portion moves relatively upward compared to the case where the cutting target portion moves downward while remaining in the vertical posture. Therefore, if the plurality of sensors are arranged to detect the position of the lower end surface of the cutting target portion after the start of the above-described posture change, the time for detecting the lower end surface is delayed, and the moving speed of the glass ribbon cannot be accurately measured. In the configuration here, since the plurality of sensors are arranged to detect the position of the lower end surface of the glass ribbon before the above-described posture change, such a problem does not occur.

[0027] (10) A second aspect of the present invention devised to solve the above problems is a method for manufacturing a glass plate, including a forming step of forming a glass ribbon from molten glass, a conveying step of conveying the glass ribbon downward, a speed measuring step of measuring the moving speed of the glass ribbon during the execution of the conveying step, and a cutting step of cutting out a sheet-like glass plate from the glass ribbon. The speed measuring step is characterized by measuring the moving speed of the glass ribbon in a non-contact manner.

[0028] According to this method for manufacturing a glass plate, substantially the same operational effects as in the case of the configuration (1) above can be obtained.

Effects of the Invention

[0029] According to the present invention, it is possible to accurately measure the movement speed of a glass ribbon without damaging the glass ribbon and without causing slippage between the glass ribbon and the object. [Brief explanation of the drawing]

[0030] [Figure 1] This is a perspective view showing the overall configuration of a glass plate manufacturing apparatus according to an embodiment of the present invention. [Figure 2] This is a longitudinal cross-sectional view taken along line AA in Figure 1. [Figure 3] A longitudinal cross-sectional side view illustrating the operation of a glass plate manufacturing apparatus according to an embodiment of the present invention. [Figure 4] A longitudinal cross-sectional side view illustrating the operation of a glass plate manufacturing apparatus according to an embodiment of the present invention. [Figure 5] A longitudinal cross-sectional side view illustrating the operation of a glass plate manufacturing apparatus according to an embodiment of the present invention. [Figure 6] This is a cross-sectional plan view illustrating the operation of the main part of a folding device, which is a component of a glass plate manufacturing apparatus according to an embodiment of the present invention. [Figure 7] A longitudinal cross-sectional side view illustrating the operation of a glass plate manufacturing apparatus according to an embodiment of the present invention. [Figure 8] A longitudinal cross-sectional side view illustrating the operation of a glass plate manufacturing apparatus according to an embodiment of the present invention. [Figure 9] This is a front view of the main components of a glass plate manufacturing apparatus according to an embodiment of the present invention, as seen from the back side of a glass ribbon. [Figure 10] This is a plan view showing a cross-section of a glass ribbon cut in the width direction. [Figure 11] This is a cross-sectional plan view illustrating the operation of a scribe device, which is a component of a glass plate manufacturing apparatus according to an embodiment of the present invention. [Figure 12] This is a side view illustrating the operation of the main part of a glass plate manufacturing apparatus according to an embodiment of the present invention. [Figure 13]A longitudinal cross-sectional side view illustrating the operation of a glass plate manufacturing apparatus according to an embodiment of the present invention. [Figure 14] This is a longitudinal cross-sectional side view showing the configuration of a glass plate manufacturing apparatus according to a modified embodiment of the present invention. [Figure 15] A perspective view showing a modified example of a scribe device, which is a component of a glass plate manufacturing apparatus according to an embodiment of the present invention. [Modes for carrying out the invention]

[0031] Hereinafter, a glass plate manufacturing apparatus and a glass plate manufacturing method according to embodiments of the present invention will be described with reference to the attached drawings.

[0032] Figure 1 is a perspective view showing the overall configuration of a glass plate manufacturing apparatus 1 according to an embodiment of the present invention, and Figure 2 is a longitudinal cross-sectional side view obtained by cutting along line AA in Figure 1. In the following description, the BB direction in Figure 1 will be described as the width direction, and the CC direction in Figure 1 will be described as the front-back direction (the same applies to the other figures).

[0033] As shown in Figures 1 and 2, the manufacturing apparatus 1 is broadly comprised of a molding apparatus 2, a conveying apparatus 3, a speed measuring apparatus 4, and a cutting apparatus 5.

[0034] The molding apparatus 2 is located inside the molding furnace 6. The molding furnace 6 is a region for forming glass ribbons R from molten glass Gm by the overflow down-draw method. The molding apparatus 2 includes a molding body 7 that forms the glass ribbon R by converging the molten glass Gm overflowing from the upper end at the lower end. Furthermore, the molding apparatus 2 includes edge rollers 8 that clamp the edges R1 and R2 of the glass ribbon R formed by the molding body 7 from both sides in the front-back direction. These edge rollers 8 cool the glass ribbon R and suppress shrinkage of the glass ribbon R in the width direction.

[0035] Some components of the conveying device 3 are located inside the annealing furnace 9. The annealing furnace 9 is a region for reducing warping and distortion of the glass ribbon R, and the inside of the annealing furnace 9 has a predetermined temperature gradient downwards. Furthermore, annealing rollers 10, which are also components of the conveying device 3, are located inside the annealing furnace 9. The annealing rollers 10 are arranged in multiple vertical stages (two stages in the illustrated example) and clamp the ends R1 and R2 of the glass ribbon R in the width direction from both sides in the front-back direction.

[0036] The remaining components of the conveying device 3 are located in the cooling chamber 11. The cooling chamber 11 is a region for cooling the glass ribbon R to near room temperature. A gas at room temperature (e.g., 20°C ± 15°C) (e.g., clean air) is supplied to the cooling chamber 11, and no heating devices such as heaters are placed there. Furthermore, the support rollers 12, which are the remaining components of the conveying device 3, are located in the cooling chamber 11. The support rollers 12 are arranged in multiple vertical stages (two stages in the illustrated example) and clamp the glass ribbon R around both ends R1 and R2 in the width direction from both sides in the front-back direction.

[0037] For convenience, in the following explanation, one end R1 in the width direction of the glass ribbon R shown in Figure 1 will be referred to as "end R1," and the other end R2 in the width direction will be referred to as "other end" (the same applies to all other figures). Also, one surface Ra of the glass ribbon R will be referred to as the front surface, and the other surface Rb will be referred to as the back surface (the same applies to all other figures).

[0038] The speed measuring device 4 is equipped with multiple sensors 30 (two in the illustrated example) that are fixed in place on the back surface Rb side of the glass ribbon R. The two sensors 30 are spaced apart on the back side of the glass ribbon R, Rb. Furthermore, the two sensors 30 are positioned at different locations in the vertical direction. The detailed configuration of the speed measuring device 4 will be described later.

[0039] The cutting device 5 includes a scribe device 15 that forms scribe lines S extending in the width direction on the back surface Rb of the glass ribbon R, and a folding device 16 that folds the glass ribbon R at the positions where the scribe lines S are formed to obtain a single sheet of glass.

[0040] The scribe device 15 includes a scribe cutter 17 (shown as a solid line in Figure 2 for convenience) positioned on the back surface Rb side of the glass ribbon R, and a traveling mechanism 18 (shown as a dashed line in Figure 2 for convenience) also positioned on the back surface Rb side of the glass ribbon R and forcing the scribe cutter 17 to move in the width direction. In this embodiment, the scribe cutter 17 is composed of a disc-shaped member having blades on its peripheral edge. When forming a scribed line S on the glass ribbon R, the scribe cutter 17 moves from one end R1 side to the other end R2 side of the glass ribbon R by the operation of the traveling mechanism 18. The scribe cutter 17 is configured to move in the front-to-back direction and in the up-and-down direction in conjunction with the traveling mechanism 18.

[0041] Furthermore, the scribe device 15 includes a support 19 positioned on the surface Ra side of the glass ribbon R. The support 19 and the scribe cutter 17 are positioned opposite each other on both sides in the front-back direction of the glass ribbon R. The support 19 is composed of a member that is elongated in the width direction and has a support surface 19a that faces the surface Ra of the glass ribbon R. The support surface 19a is a plane that extends linearly in the width direction and is parallel to the vertical plane. The support 19 is configured to move in the front-back direction and in the vertical direction.

[0042] The folding device 16 consists of an upper folding device 20 positioned relatively above and a lower folding device 21 positioned relatively below.

[0043] The upper splitting device 20 includes a splitting body 22 positioned on the surface Ra side of the glass ribbon R. The splitting body 22 is composed of a member that is elongated in the width direction. Furthermore, the splitting body 22 has a contact end 22a that faces the surface Ra of the glass ribbon R. The contact end 22a is curved so as to be convex toward the tip side when viewed from the side.

[0044] Furthermore, the upper folding device 20 includes a dust collector 23 positioned on the back surface Rb side of the glass ribbon R. The dust collector 23 is elongated in the width direction. In addition, the dust collector 23 has a suction section (not shown) that sucks up glass powder generated when the glass ribbon R is folded. Both the folding body 22 and the dust collector 23 are configured to move in the front-to-back direction and in the up-and-down direction.

[0045] The lower folding device 21 includes a support mechanism 25 which serves as a support for the cutting target Rc, the part from which a single sheet of glass plate is cut from the glass ribbon R. The support mechanism 25 has a pair of arm members 24 positioned at one end R1 and the other end R2 in the width direction of the glass ribbon R. Both arm members 24 extend in the vertical direction. Furthermore, the support mechanism 25 has gripping members 27 attached to multiple locations (two locations in the illustrated example) in the vertical direction of each of the pair of arm members 24. Each gripping member 27 is open and closed, as shown by the solid line and the dashed line. The pair of arm members 24 are configured to rotate together in a vertical plane perpendicular to the width direction.

[0046] Furthermore, a regulating roller 29 is positioned below the conveying device 3 (the lowest support roller 12) and above the scribe device 15, which restricts the swaying of the glass ribbon R by clamping it from both sides in the front-back direction. The regulating roller 29 is positioned in the region on one end R1 side of the center in the width direction of the glass ribbon R, and in the region on the other end R2 side of the center in the width direction of the glass ribbon R. Therefore, the glass ribbon R is clamped by two pairs of regulating rollers 29.

[0047] Here, we will explain the basic operation of this manufacturing apparatus 1, namely the operation of the scribe device 15 and the folding device 16.

[0048] First, as shown in Figure 3, when the glass ribbon R is moving downward, the arm member 24 of the folding device 16 (lower folding device 21) moves downward in accordance with the movement, and the gripping member 27 grips the portion Rc of the glass ribbon R that is to be cut. Even after gripping, the arm member 24 continues to move downward in accordance with the glass ribbon R. At this time, the scribe cutter 17 and support 19 of the scribe device 15, and the folded body 22 and dust collector 23 of the folding device 16 (upper folding device 20) are waiting in a retracted position.

[0049] Next, as shown in Figure 4, the scribe cutter 17 and support 19 move downward, following the glass ribbon R, from the retracted position to the contact position. With the support 19 in contact with the surface Ra of the glass ribbon R, the scribe cutter 17 travels from one end R1 to the other end R2 of the glass ribbon R. This forms a scribe line S extending along the width direction on the back surface Rb of the glass ribbon R. The scribe cutter 17 and support 19 move downward, following the glass ribbon R, until the formation of the scribe line S is complete. After the formation of the scribe line S is complete, the scribe cutter 17 and support 19 return to their original retracted position.

[0050] Subsequently, as shown in Figures 5 and 6, the folding body 22 and the dust collector 23 move downward, following the glass ribbon R, from the retracted position to the contact position. In this case, the contact end 22a of the folding body 22 is in contact with the surface Ra of the glass ribbon R, while the dust collector 23 is slightly separated from the back surface Rb of the glass ribbon R. At this point, as shown in Figure 6, in a plan view, the glass ribbon R extends in a straight line in the width direction, following the straight shape of the contact end 22a of the folding body 22.

[0051] Under these conditions, as shown in Figure 7, the pair of arm members 24 rotate together, causing their orientation to shift from a vertical to an inclined position. This applies bending stress to the formation of the scribe line S on the glass ribbon R, due to the longitudinal curvature. This bending stress causes the glass ribbon R to break along the scribe line S, and as shown in Figure 8, a glass plate Gp is ​​cut from the glass ribbon R. The glass powder generated during this breaking process is sucked into the dust collector 23.

[0052] Here, the thickness of the glass ribbon R is 10 μm to 1000 μm. The upper limit of this thickness is preferably 700 μm or less, and more preferably 500 μm or less. The length in the width direction of the glass ribbon R is 500 mm to 3800 mm. Furthermore, the glass plate Gp cut from the glass ribbon R is used as a glass substrate or cover glass in panel displays such as liquid crystal displays and organic EL displays.

[0053] Next, we will describe the detailed configuration of the speed measuring device 4.

[0054] As shown in Figure 2, the two sensors 30 constituting the speed measuring device 4 measure the movement speed of the glass ribbon R non-contact. This makes it possible to accurately measure the movement speed of the glass ribbon R without damaging the glass ribbon R and without causing problems such as slippage that can occur when using a contact-type speed measuring device.

[0055] The two sensors 30 are positioned in a region below the position where the folding device 16 folds the glass ribbon R (in the illustrated example, the region below the upper folding device 20). More specifically, the two sensors 30 are positioned such that their respective detection positions (measurement positions) Rw and Rx are in a region below the folding position of the glass ribbon R by the folding device 16. The two sensors 30 then detect the position of the lower end surface (cut surface) Rv of the glass ribbon R formed by the folding of the glass ribbon R by the folding device 16. In this embodiment, the two sensors 30 are not tilted in either the vertical or front-to-back direction and are pointed in the same direction, however, one sensor 30 and the other sensor 30 may be pointed in different directions.

[0056] The two sensors 30 can detect the presence or absence of the glass ribbon R. As shown in the figure example, the two sensors 30, which are placed only on the back surface Rb side of the glass ribbon R, can be reflective laser sensors, ultrasonic sensors, thermographic sensors, etc. When the two sensors 30 are placed in this manner, the manufacturing apparatus 1 can be made more compact. More specifically, when the glass ribbon R is broken, if the orientation of the part of the glass ribbon R to be cut Rc changes from a vertical orientation to an inclined orientation, the part of the glass ribbon R to be cut Rc moves away from the two sensors 30. Therefore, the two sensors 30 can be placed closer to the glass ribbon R in a vertical orientation, thus making the manufacturing apparatus 1 more compact. However, although this advantage cannot be obtained, the two sensors 30 may also be placed only on the front surface Ra side of the glass ribbon R.

[0057] On the other hand, the two sensors 30 may be transmissive laser sensors, but in this case, unlike the example shown, it is necessary to arrange the components of each sensor 30 (light-emitting part and light-receiving part) on both the front surface Ra side and the back surface Rb side of the glass ribbon R. When transmissive laser sensors are used, accurate measurements can be performed without being affected even if the glass ribbon R vibrates. This advantage can be obtained in the same way when thermography is used, as described above.

[0058] Here, since the glass ribbon R is a transparent body that is continuously molded, it is difficult to measure the movement speed of the glass ribbon R non-contact by optical means or the like. In contrast, if the configuration is such that the position of the lower end surface Rv of the glass ribbon R is detected as described above, the position of the lower end surface Rv can be easily detected non-contact by the sensor 30 that detects the presence or absence of the glass ribbon R, and the movement speed can be accurately measured.

[0059] Furthermore, the speed measuring device 4 is equipped with a calculation unit 31. The calculation unit 31 calculates the moving speed of the glass ribbon R using the time at which each of the two sensors 30 detects the position of the lower end surface Rv of the glass ribbon R, and the distance Lx between the two sensors 30. In this case, the distance Lx between the two sensors 30 means the vertical separation distance between the respective sensing parts 30a of the two sensors 30. Furthermore, considering that the orientations of the two sensors 30 may differ as described above, the distance Lx between the two sensors 30 means the vertical separation distance between the respective detection positions (measurement positions) Rw and Rx on the glass ribbon R by the two sensors 30. The moving speed of the glass ribbon R calculated by the calculation unit 31 is the value obtained by dividing the distance Lx between the two sensors 30 by the difference in the time at which each of the two sensors 30 detected the position.

[0060] Figure 9 is a front view of the main parts of the manufacturing apparatus 1, viewed from the back surface Rb side of the glass ribbon R. As shown in the figure, the annealing roller 10 and support roller 12 of the conveying apparatus 3 are positioned closer to the center in the width direction than the edge roller 8. In this embodiment, the annealing roller 10 and the support roller 12 are positioned at the same location in the width direction.

[0061] Therefore, the contact marks 41 (hereinafter referred to as the first contact marks 41) of the glass ribbon R with the annealing roller 10 and the support roller 12 are located closer to the center in the width direction than the contact marks 42 (hereinafter referred to as the second contact marks 42) of the glass ribbon R with the edge roller 8. In the figure, the first contact marks 41 are shown as a striated region with a relatively large pitch of cross-hatching, and the second contact marks 42 are shown as a striated region with a relatively small pitch of cross-hatching. In this case, the first contact marks 41 and the second contact marks 42 are spaced apart in the width direction, and a striated gap region 43 (a region without cross-hatching 43) exists between the first contact marks 41 and the second contact marks 42.

[0062] Figure 10 is a plan view showing a cross-section of a glass ribbon R when it is cut along its width. As shown in the figure, a tab Rm is formed in the region on the R1 side of the glass ribbon R in the width direction, and this tab is thicker than the central part in the width direction. Furthermore, an uneven surface Rn is formed in the region on the R1 side of the tab Rm in the width direction. This region where the uneven surface Rn is formed is the second contact mark 42. The region on the Rm where the uneven surface Rn is not formed is located within the striated gap region 43. The above explanation also applies to the region on the R2 side of the glass ribbon R in the width direction. Therefore, the same reference numerals are used for the same constituent elements in the region on the R2 side of the glass ribbon R shown in the figure.

[0063] Here, as shown in Figure 9, the two sensors 30 are positioned at the same location in the width direction. More specifically, the sensing parts 30a of each of the two sensors 30 are positioned at the same location in the width direction. More specifically, the two sensors 30 are positioned so that their respective detection positions (measurement positions) on the glass ribbon R are at the same location in the width direction. In this way, even if there are cracks or chips in the lower end surface Rv of the glass ribbon R, or if the lower end surface Rv is cut at an angle, that is, even if the lower end surface Rv of the glass ribbon R does not extend in a straight line along the horizontal direction, the movement speed of the glass ribbon R can be accurately measured.

[0064] Furthermore, the two sensors 30 are positioned to measure the movement speed of the region on the side of one end R1 rather than the center Rz in the width direction of the glass ribbon R. This arrangement provides the following effect. Specifically, as shown in Figure 11, when the scribe cutter 17 is run from one end R1 to the other end R2 in the width direction of the glass ribbon R to form a scribe line S, wrinkles Rp may occur in the glass ribbon R. More specifically, wrinkles Rp occur in the latter half of the time from the start to the end of the formation of the scribe line S by the scribe cutter 17.

[0065] Therefore, wrinkles Rp occur in the region on the terminal S2 side of the scribe line S in the glass ribbon R shown in Figure 9. Consequently, if the two sensors 30 are arranged to measure the movement speed of the region on the terminal S2 side of the scribe line S in the glass ribbon R, it becomes difficult to accurately measure the movement speed of the glass ribbon R due to the influence of wrinkles Rp.

[0066] Therefore, by arranging the two sensors 30 to measure the movement speed of the region on the starting end S1 side of the scribe line S in the glass ribbon R, that is, the region on the end R1 side of the center Rz in the width direction of the glass ribbon R as described above, the movement speed of the glass ribbon R can be accurately measured without being affected by wrinkles Rp.

[0067] In the following explanation based on Figure 9, the first contact mark 41, the second contact mark 42, the ear portion Rm, and the gap region 43 refer to the respective elements 41, 42, Gm, and 43 located on the R1 side of one end in the width direction of the glass ribbon R.

[0068] The two sensors 30 are positioned to measure the movement speed of the area on the central side in the width direction relative to the first contact mark 41. Therefore, the two sensors 30 are positioned to measure the movement speed of the area on the central side in the width direction relative to the second contact mark 42, the ear portion Rm, and the gap region 43.

[0069] Even with this arrangement, the two sensors 30 can accurately measure the movement speed of the glass ribbon R for the following reasons. Specifically, because irregularities Rn are formed on the second contact mark 42, if the two sensors 30 are arranged to measure the movement speed of the second contact mark 42, the presence of irregularities Rn causes light from the sensors 30 to be scattered, making it impossible to accurately measure the movement speed of the glass ribbon R. In addition, because the area where the second contact mark 42 is formed has a large amount of residual stress, the area where the second contact mark 42 is formed may break and fall off while the glass ribbon R is being transported downwards. This breakage also prevents the two sensors 30 from accurately measuring the movement speed of the glass ribbon R. The same problem occurs with the ear portion Rm. Therefore, if the two sensors 30 are arranged to measure the movement speed of the area on the central side in the width direction, rather than the second contact mark 42 and the ear portion Rm, the above problems will not occur.

[0070] Furthermore, minute cracks may form in the first contact mark 41 when glass powder or other materials adhering to the annealing roller 10 and support roller 12 are pressed against it by the annealing roller 10 and support roller 12. As a result, the presence of these cracks causes light from the sensor 30 to be scattered, making it impossible to accurately measure the movement speed of the glass ribbon R. However, if the two sensors 30 are positioned to measure the movement speed in the area closer to the center in the width direction than the first contact mark 41, this problem can be avoided.

[0071] Here, the two sensors 30 may be arranged to measure the speed of movement within the gap region 43. Therefore, the two sensors 30 may also measure the speed of movement in areas of the ear portion Rm where no irregularities Rn are formed. However, since areas of the ear portion Rm where no irregularities Rn are formed may have residual stress and some variation in thickness, it is preferable that the two sensors 30 be arranged to measure the speed while avoiding such areas.

[0072] Furthermore, unlike the illustrated example, if the widthwise position of the slow-cooling roller 10 differs from the widthwise position of the support roller 12, the widthwise length of the first contact mark 41 will increase, or the first contact mark 41 will split into two. Even in such cases, the two sensors 30 are arranged to measure the movement speed of the region that does not interfere with the first contact mark 41. Therefore, the two sensors 30 may also be arranged to measure the movement speed of the striated gap region between the two first contact marks 41.

[0073] In the illustrated example, the second contact mark 42 is located closer to the center in the width direction at the height where the two sensors 30 are positioned than at a position near the bottom of the edge roller 8. In this case, the width direction position of the second contact mark 42 refers to its width direction position at the height where the two sensors 30 are positioned. Therefore, "the area closer to the center in the width direction than the second contact mark 42" means "the area closer to the center in the width direction than the second contact mark 42 at the height where the two sensors 30 are positioned."

[0074] Furthermore, the two sensors 30 are positioned to measure the movement speed of the region of the glass ribbon R between the starting end S1 and the ending end S2 of the scribe line S. Here, the region of the glass ribbon R on one end R1 side of the starting end S1 of the scribe line S, and the region on the other end R2 side of the ending end S2 of the scribe line S, are not folded along the scribe line S, so the cut end surface (lower end surface) Rv of the glass ribbon R is prone to damage. Therefore, after the upper sensor 30 detects the cut end surface Rv, but before the lower sensor 30 detects the cut end surface Rv, new chips or defects may occur on the cut end surface Rv of the region on the one end R1 side of the starting end S1 of the scribe line S, or on the cut end surface Rv of the region on the other end R2 side of the ending end S2 of the scribe line S. As a result, the movement speed of the glass ribbon R cannot be accurately measured in those regions. In contrast, as mentioned above, if the cutting surface Rv is in the intermediate region between the starting point S1 and the ending point S2 of the scribe line S, the cutting surface Rv will be the end surface that has been folded along the scribe line S, and therefore such a problem will not occur.

[0075] Furthermore, the two sensors 30 are positioned to detect the position of the lower end surface Rv of the glass ribbon R before the support mechanism 25 of the folding device 16 changes the orientation of the portion Rc to be cut from a vertical position to an inclined position. Here, as shown in Figure 12, after the support mechanism 25 changes the orientation of the portion Rc to be cut from a vertical position to an inclined position, the position of the lower end surface Rv of the portion Rc moves relatively upward by δ1 compared to when the portion Rc moves downward while remaining in a vertical position (shown by a dashed line in the same figure) (shown by a solid line in the same figure). Therefore, if the lower sensor 30 is positioned to detect the position of the lower end surface Rv of the portion Rc after the above orientation change, the time at which the lower sensor 30 detects the lower end surface Rv of the portion Rc will be delayed by the amount corresponding to δ1. The same applies if the upper sensor 30 is positioned to detect the position of the lower end surface Rv of the portion Rc after the above orientation change. Therefore, the movement speed of the glass ribbon R cannot be accurately measured. However, if the two sensors 30 are arranged to detect the position of the lower end surface Rv of the part to be cut Rc before the above-mentioned change in posture, such a problem will not occur.

[0076] In addition, a signal indicating the movement speed of the glass ribbon R, calculated by the speed measuring device 4 (calculation unit 31), is sent to the cutting device 5 (scribe device 15 and folding device 16). As a result, the scribe cutter 17, support 19, folding body 22, dust collector 23, and the pair of arm members 24 move downward in accordance with the movement speed of the glass ribbon R calculated by the calculation unit 31. Here, it is conceivable that the downward movement speed of the cutting device 5 should follow the conveying speed of the glass ribbon R by the conveying device 3, but slippage can inevitably occur between the rollers 10 and 12 of the conveying device 3 and the glass ribbon R. Therefore, it is difficult to accurately match the movement speed of the glass ribbon R with the movement speed of the cutting device 5. On the other hand, as described above, if the movement speeds of the components 17, 19, 22, 23, and 24 of the cutting device 5 are made to follow the movement speed of the glass ribbon R calculated by the calculation unit 31, such problems will not occur.

[0077] In the above configuration, it is preferable that the speed measuring device 4 measures the movement speed of the glass ribbon R when the gripping member 27 of the support mechanism 25 in the folding device 16 is moving downward while gripping the portion Rc of the glass ribbon R that is to be cut, as shown in Figure 3 above. That is, as shown in Figure 13, if the glass ribbon R has a warp that curves in the vertical direction, the lower end surface Rv of the glass ribbon R may swing up and down due to the effect of the warp between the time the glass ribbon R is folded by the folding device 16 and the time the glass ribbon R is gripped by the gripping member 27. As a result, it becomes impossible for the speed measuring device 4 to accurately measure the movement speed of the glass ribbon R. Therefore, it is preferable that the speed measuring device 4 measures the movement speed of the glass ribbon R when the gripping member 27 is gripping the glass ribbon R and moving downward, and does not measure the movement speed of the glass ribbon R at any other time. In this case, during periods when the movement speed of the glass ribbon R is not being measured, the movement speeds of the components 17, 19, 22, 23, and 24 of the cutting device 5 should be adjusted to follow the most recently measured movement speed of the glass ribbon R by the speed measuring device 4. Furthermore, if no problems arise due to the warping of the glass ribbon R, the speed measuring device 4 may always measure the movement speed of the glass ribbon R.

[0078] Furthermore, as a modification of this embodiment, the two sensors 30 of the speed measuring device 4 may measure the moving speed of the glass ribbon R by detecting the scribe lines S formed on the glass ribbon R. In this modification, the arrangement of the two sensors 30 in the width direction is as shown in Figure 9. That is, the two sensors 30 are arranged to measure the moving speed in the region between the start end S1 and the end end S2 of the scribe line S. On the other hand, the arrangement of the two sensors 30 in the vertical direction is as shown in Figure 14. That is, the two sensors 30 are arranged below the scribe device 15 and above the folding device 16. Specifically, the two sensors 30 are arranged such that their respective detection positions (measurement positions) Rw and Rx exist in the region below the position where the scribe lines S are formed by the scribe device 15 on the glass ribbon R and above the folding position of the glass ribbon R by the folding device 16.

[0079] The calculation unit 31 of the speed measuring device 4 then calculates the moving speed of the glass ribbon R using the time at which each of the two sensors 30 detects the position of the scribe line S formed on the glass ribbon R, and the distance between the two sensors 30. In this case, the moving speed of the glass ribbon R calculated by the calculation unit 31 is the value obtained by dividing the distance between the two sensors 30 by the difference in the time at which each of the two sensors 30 detected the scribe line S. In this modified example, thermographic cameras or cameras (for example, industrial cameras for inspection) can be used as the two sensors 30.

[0080] Next, a method for manufacturing a glass plate according to an embodiment of the present invention will be described. This manufacturing method comprises a molding step, a conveying step, a cutting step, and a speed measurement step.

[0081] The molding process, conveying process, and cutting process are the same as those described in the manufacturing method according to the first embodiment.

[0082] The speed measurement process is a non-contact process for measuring the movement speed of the glass ribbon. A non-contact sensor is used in this speed measurement process.

[0083] Although embodiments of the present invention have been described above, the embodiments of the present invention are not limited thereto, and various modifications can be made without departing from the spirit of the invention.

[0084] For example, the scribe device 15 in the above embodiment may be replaced with a scribe device 15 as shown in Figure 15. More specifically, the scribe device 15 shown in Figure 15 has a support body 19 that supports a scribe cutter 17, which is positioned on the back surface Rb side of the glass ribbon R, from the surface Ra side of the glass ribbon R. This support body 19 is composed of a roller-shaped first support rotating body. This first support rotating body 19 moves together with the scribe cutter 17 in the direction of arrow E (the direction from one end R1 side to the other end R2 side in the width direction of the glass ribbon R). Furthermore, this scribe device 15 is equipped with a coating roller 45 that moves ahead of the scribe cutter 17 and at the same speed in the direction of arrow E on the back surface Rb side of the glass ribbon R. The coating roller 45 applies a liquid such as ethanol or methanol to the back surface Rb of the glass ribbon R. In addition, this scribe device 15 is equipped with a second support rotating body 46 that supports the coating roller 45 from the surface Ra side of the glass ribbon R. This second support rotating body 46 moves together with the coating roller 45 in the direction of arrow E. When a scribe line S is formed on a glass ribbon R using a scribe device 15 with such a configuration, wrinkles Rp may occur in the region of the glass ribbon R on the terminal S2 side of the scribe line S, as in the case described above.

[0085] In the above embodiment, the arrangement of the two sensors 30 described with reference to Figure 9 may also be as shown below. That is, when measuring the moving speed of the glass ribbon R with the speed measuring device 4, wrinkles Rp that occur due to the formation of scribe lines S on the glass ribbon R may not be a problem. In such cases, the two sensors 30 may be arranged to measure the moving speed of the center Rz in the width direction of the glass ribbon R, or they may be arranged to measure the moving speed of the region on the other end R2 side of the center Rz in the width direction of the glass ribbon R. When the two sensors 30 are arranged to measure the moving speed of the region on the other end R2 side of the center Rz in the width direction of the glass ribbon R, the positional relationship of the two sensors 30 with respect to the first contact mark 41, second contact mark 42, ear portion Rm, and gap region 43 on the other end R2 side of the glass ribbon R in the width direction is the same as the positional relationship of the two sensors 30 with respect to each of those elements 41, 42, Rm, and 43 on the one end R1 side of the glass ribbon R in the width direction, as already described.

[0086] In the above embodiment, the present invention was applied to an apparatus and method for manufacturing glass plates using the overflow downdraw method, but the present invention may also be applied to an apparatus and method for manufacturing glass plates using other methods, such as the slot downdraw method.

[0087] In the above embodiment, when the glass ribbon R is broken by the breaking device 16, the broken body 22 is in contact with the glass ribbon R while bending stress is applied to the glass ribbon R. However, the broken body 22 may be brought into contact with the glass ribbon R while bending stress is applied to the glass ribbon R.

[0088] In the above embodiment, when the glass ribbon R is broken by the breaking device 16, the broken body 22 is brought into contact with the position where the scribe line S is formed on the glass ribbon R. However, the broken body 22 may also be brought into contact with a position above the scribe line S on the glass ribbon R (including the abutment described above).

[0089] In the above embodiment, the starting end S1 and ending end S2 of the scribe line S are located on the widthwise side of the first contact mark 41 of the glass ribbon R. However, the starting end S1 and ending end S2 of the scribe line S may be located within the first contact mark 41 or within the groove-shaped gap region 43. However, it is preferable that the starting end S1 and ending end S2 of the scribe line S are located on the widthwise side of the lug portion Rm of the glass ribbon R.

[0090] In the above embodiment, two sensors 30 are placed at different positions in the vertical direction, but three or more sensors 30 may be placed at different positions in the vertical direction. Even in this case, only two sensors 30 are actually used, and if, for example, one of the sensors 30 being used malfunctions or becomes unusable due to reaching the end of its lifespan, the system can switch to using another sensor 30. This allows for continuous measurement of the glass ribbon R's movement speed without interruption. In this case, multiple movement speeds can be calculated from the signals of three or more sensors 30, the movement speed of the components of the cutting device 5 can be made to follow the movement speed of one of these speeds, and the remaining calculated movement speeds can be used to verify whether the one movement speed is accurate. [Explanation of Symbols]

[0091] 1 Manufacturing equipment 2 Molding equipment 3. Conveying device 4 Speed ​​measuring device 5 Cutting device 6 Molding furnace 7 Molded body 8 Edge rollers 9 Annealing furnace 10 Uncooled roller 11 Cooling room 12 Support rollers 15. Scribe device 16 Folding device 17 Scribe Cutter 19 Support (First Support Rotating Body) 22 Folded body 25 Support mechanism (support part) 27 Gripping member 30 sensors Gm molten glass GP glass plate Lx: Distance between multiple sensors R Glass Ribbon R1 One end of the glass ribbon in the width direction (one end in the width direction) R2 The other end of the glass ribbon in the width direction (the end on the other side in the width direction) Surface (one side) of Ra glass ribbon Rb Glass ribbon back side (the other side) Cutting area of ​​Rc glass ribbon Rm Glass Ribbon Ears Rv Glass ribbon lower end face (cut end face) Rz Glass ribbon width direction center (center position) S scribe line S1 scribe line starting point S2 scribe line termination

Claims

1. A glass plate manufacturing apparatus comprising: a molding apparatus for forming a glass ribbon from molten glass; a conveying apparatus for conveying the glass ribbon downward; a speed measuring apparatus for measuring the movement speed of the glass ribbon conveyed downward by the conveying apparatus; and a cutting apparatus for cutting out a single sheet of glass plate from the glass ribbon, The speed measuring device is a glass plate manufacturing apparatus characterized by measuring the movement speed of the glass ribbon in a non-contact manner.

2. The cutting apparatus comprises a scribe device for forming scribe lines on the glass ribbon along the width direction perpendicular to the transport direction of the glass ribbon, and a folding device for folding the glass ribbon at the positions where the scribe lines are formed to obtain a single sheet of glass. The speed measuring device is positioned below the position where the breaking device breaks the glass ribbon and includes a plurality of sensors capable of detecting the presence or absence of the glass ribbon, the plurality of sensors being positioned at different locations in the vertical direction. A glass plate manufacturing apparatus according to claim 1, which calculates the moving speed of the glass ribbon using the time at which each of the plurality of sensors detects the position of the lower end surface of the glass ribbon formed by folding by the folding device, and the vertical distance between each of the plurality of sensors.

3. The glass ribbon has tabs at both ends in the width direction perpendicular to the transport direction of the glass ribbon, which are thicker than the central part in the width direction. The glass plate manufacturing apparatus according to claim 1 or 2, wherein the speed measuring device measures the movement speed of the region of the glass ribbon that is closer to the center in the width direction than the ear portion.

4. The glass plate manufacturing apparatus according to claim 2, wherein the speed measuring device measures the moving speed of the region in the glass ribbon between the start end and the end end of the scribe line.

5. The scribe device forms the scribe line from one end to the other end in the width direction of the glass ribbon. The glass plate manufacturing apparatus according to claim 2, wherein the speed measuring device measures the movement speed of the region on one end side of the glass ribbon, which is located more towards the center in the width direction.

6. The glass plate manufacturing apparatus according to claim 1 or 2, wherein the cutting device moves downward in accordance with the moving speed of the glass ribbon measured by the speed measuring device.

7. The glass plate manufacturing apparatus according to claim 2, wherein the plurality of sensors are a transmissive laser sensor, a reflective laser sensor, an ultrasonic sensor, or a thermograph.

8. The glass plate manufacturing apparatus according to claim 2, wherein the plurality of sensors are arranged at the same position in the width direction.

9. The folding device includes a support portion that supports the portion of the glass ribbon from which the sheet-shaped glass plate is to be cut out, The support portion changes the orientation of the portion to be cut from a vertical position to an inclined position, thereby applying bending stress to the formation position of the scribe line, and cutting out the portion to be cut from the glass ribbon. The glass plate manufacturing apparatus according to claim 2, wherein the plurality of sensors are arranged to detect the position of the lower end surface of the glass ribbon before the support portion changes the orientation of the portion to be cut from the vertical orientation to the inclined orientation.

10. A method for manufacturing a glass plate, comprising: a molding step of forming a glass ribbon from molten glass; a conveying step of conveying the glass ribbon downward; a speed measuring step of measuring the movement speed of the glass ribbon during the conveying step; and a cutting step of cutting out a single sheet of glass plate from the glass ribbon, A method for manufacturing a glass plate, characterized in that the movement speed of the glass ribbon is measured non-contact in the speed measurement step.

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