JP2003342030A - Cooling reinforcement method of glass plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling reinforcement method of a glass plate using mist cooling without damaging the glass plate caused by dropping of the excess mist on the glass plate nor generating reheat. <P>SOLUTION: In the cooling reinforcement method of a glass plate, mist cooling followed by air cooling for the glass plate 1 is performed using a cooling apparatus 3 for the glass plate provided with a mist cooling part 4 which spouts misty water, an air cooling part 5 which spouts air and a conveying means 25 for the glass plate wherein the time is within 0.5 sec from completion of mist cooling with the mist cooling part 4 to initiation of air cooling with the air cooling part 5. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass plate strengthening method for cooling and strengthening a glass plate.

[0002]

2. Description of the Related Art When manufacturing tempered glass used for automobile window glass or the like, a glass plate heated to near the softening point is cooled from the surface to form a compressive stress layer on the surface and a tensile stress layer inside. The glass plate is strengthened by the physical strengthening method. Conventionally, the glass plate conveyed from the heating furnace is cooled by blowing air at room temperature. On the other hand, with the recent thinning of glass plates, a higher cooling capacity than in the past is required in order to rapidly cool the surface layer to generate a stress difference with the inside. Therefore, when the thin glass plate is cooled only by the air jet, it is necessary to increase the air supply pressure to increase the jet velocity. However, because the air supply pressure is high, there are traces of air blown on the glass plate,
Due to the high velocity of the jet, there was a problem that the glass plate was bent by wind pressure. In addition, the operating costs of the blower necessary for these operations also increase, and there are problems such as enlargement of the blower and waste of resources.

For this reason, cooling using mist (fog-like water) has been proposed as a means for obtaining a high cooling capacity. The cooling method using this mist is to cool the glass plate conveyed from the heating furnace into the cooling device by spraying the mist. However, in this method, if mist cooling is performed until the cooling is completed, a liquid film of mist spreads on the surface of the glass plate, the cooling capacity becomes too strong, and an excessive stress difference occurs inside and outside the glass plate, The glass plate was damaged.
In addition, the mist may adhere to surrounding members and condense to form excess mist, which may be dropped on the glass plate and damaged by thermal shock.

On the other hand, US Pat. No. 5,772,717 describes a method for strengthening a glass plate using both mist cooling and air cooling. The glass plate strengthening method described in this publication aims at preventing damage to the glass plate due to excessive mist supply by sequentially cooling the glass plate with mist and air while conveying the glass plate with rollers.

[0005]

However, in the glass plate strengthening method described in the above-mentioned US publication, there is a risk that the glass plate will be damaged by the excess mist attached to the transfer roller for mounting and transferring the glass plate. If the time required to cool the air after mist cooling is long, the temperature difference between the inside and the outside of the glass plate caused by cooling will be alleviated (reheat),
The desired strength cannot be obtained. Since the technique described in this publication does not consider reheat avoidance at all, the cooling device described in this publication cannot be used as it is.

The present invention has been made in consideration of the above-mentioned prior art, and a glass using mist cooling is used without excessive mist dropping on the glass plate to damage the glass plate or reheat the glass plate. An object of the present invention is to provide a glass plate cooling and strengthening method that enables strengthening of a plate.

[0007]

In order to achieve the above-mentioned object, in the present invention, a mist cooling section for ejecting mist-like water,
A glass plate cooling and strengthening method for performing air cooling after mist-cooling a glass plate using a glass plate cooling device comprising an air cooling unit for ejecting air, and a glass plate conveying means for conveying a glass plate, There is provided a glass plate cooling and strengthening method, wherein the period from the end of mist cooling by the mist cooling unit to the start of air cooling by the air cooling unit is within 0.5 seconds.

According to this structure, since the air is cooled before the reheat which eliminates the temperature difference between the inside and the outside of the glass sheet caused by the mist cooling is eliminated, the high cooling capacity of the mist cooling is effectively utilized. It is possible to suppress the excessive cooling due to the mist cooling by the air cooling and to promote the evaporation of the surplus mist to prevent the glass plate from being damaged by the dropping of water droplets on the surface of the glass plate.

[0009] In a preferred configuration example, the glass plate conveying means is constituted by arranging a plurality of cylindrical conveying rollers, a glass plate is placed on the conveying rollers, and the plurality of glass plates are continuously arranged in the mist cooling section. It is characterized in that the air cooling section is sequentially passed through to cool.

According to this structure, the glass plates can be strengthened by effectively cooling the glass plates without damaging the glass plates while continuously carrying the glass plates by using the carrying rollers.

In a preferred configuration example, the glass plate conveying means is provided with a cooling ring corresponding to the shape of the glass plate, and the glass plates are placed on the cooling ring, and the glass plates are transferred one by one to the mist cooling section and the air. It is characterized in that it is conveyed to the cooling section in order and cooled.

According to this structure, even in the case of the batch type in which the glass plates are conveyed one by one using the cooling ring, the glass plates can be strengthened by performing effective cooling without damaging the glass plates.

In a preferred configuration example, the mist cooling portion is cooled while shielding the left and right edge portions in the conveying direction of the glass sheet.

According to this structure, since the left and right edge portions of the glass plate, which are likely to be the starting points of the breakage due to the rapid cooling by the mist, are shielded from the mist jet, the breakage of the glass plate can be prevented.

In a preferred configuration example, the mist injection is stopped with respect to the glass plate passing through the mist cooling section at a timing when front and rear edge portions in the transport direction pass through the mist cooling section.

According to this structure, since the mist is not jetted to the front and rear edge portions of the glass plate which are likely to be the starting point of the breakage due to the rapid cooling by the mist, the breakage of the glass plate can be prevented.

A preferred configuration example is characterized in that an intake duct is provided in the vicinity of the mist cooling section, and the mist of the glass plate is cooled while the mist is sucked by the intake duct.

According to this structure, since the excess mist scattered around by the mist injection is sucked by the intake duct, the excess mist does not adhere to the peripheral portion of the apparatus, and therefore the adhered excess mist drops on the glass plate. This prevents the glass plate from being damaged.

In a preferred configuration example, the mist cooling of the glass plate is performed while the peripheral devices such as the transport roller and the air cooling unit in the vicinity of the mist cooling unit are heated.

According to this structure, since the surplus mist adhering to the rotating conveying roller can be evaporated, the surplus mist on the roller adheres to the glass plate conveyed on the roller and the glass plate is damaged. Can be prevented.

A preferred configuration example is characterized in that a scraper for contacting the mist cooling portion or the transportation roller in the vicinity thereof to remove water adhering to the transportation roller is provided.

According to this structure, since the surplus mist adhering to the rotating conveying roller can be removed by scraping it off or wiping it off, the surplus mist on the roller adheres to the glass plate conveyed on the roller. It is possible to prevent the plate from being damaged.

[0023]

1 is a schematic view of a cooling and strengthening device using a conveying roller. As shown in the figure, the glass plate 1 formed into a predetermined shape is heated in a heating furnace or the like, and then placed on a plurality of conveyor rollers 2 constituting a conveyor 25, conveyed in the direction of arrow K and cooled. It passes between the devices 3. The cooling device 3 is installed above and below the conveyor 25 and includes a mist cooling unit 4 and an air cooling unit 5, respectively. The mist cooling unit 4 is provided with a plurality of mist nozzles (mist injection holes) 6 for injecting mist (mist-like water). A plurality of (6 in the figure) mist nozzles 6 are arranged in one row or in a plurality of rows at intervals so that the mist can be uniformly sprayed on the glass surface (only one row is shown in the figure). The mist cooling capacity of the mist cooling unit 4 is determined by the amount of water supplied per unit area. The amount of water supplied can be set arbitrarily within the range of 0 to 5.0 kg / sec per m ² , and the thickness of glass plate, temperature,
It is set according to the transport speed.

The mist nozzle may be an atomizing type in which water is atomized by an air flow, or an ultrasonic type in which water is atomized by ultrasonic vibration. In any case, atomized water is sprayed from the mist nozzle 6 onto the glass plate surface. In this case, each mist nozzle 6
For example, as a double pipe structure, water or atomized water may be supplied from the inner pipe, and air may flow from the outer pipe. The mist injection from each mist nozzle 6 is turned on / off by, for example, a solenoid valve.
It can be turned off.

The air cooling unit 5 comprises an air chamber 8 having a plurality of air nozzles (air injection holes) 7 for injecting air. The air chamber 8 is connected to a blower (not shown).
The air-cooling capacity of the air-cooling unit 5 can be arbitrarily set within a range in which the heat transfer coefficient on the glass surface to be cooled is in the range of 150 to 700 W / m ² K. It is set according to. Further, the distance between the glass plate 1 to be cooled and the air nozzle 7 can be adjusted independently of the mist cooling unit 4, and is 15 mm to 15 mm depending on the required cooling capacity.
It is set in the range of 200 mm. The mist cooling unit 4 and the air cooling unit 5 are provided close to each other in order to shorten the transition time between the mist cooling and the air cooling so as not to cause reheat, as described later.

When the glass plate 1 is cooled by the cooling device 3 described above, the glass plate 1 conveyed by the conveying roller 2 from the heating furnace (not shown) passes through the mist cooling section 4 and then from the mist injection hole 6. The mist is sprayed on the upper and lower surfaces of the glass plate 1, and the heat is taken by the heat of boiling evaporation of the mist to be cooled. After that, the glass plate 1 is conveyed to the air cooling unit 5 and blown with air to be cooled.

Table 1 is a table showing the relationship between the time required from mist cooling to air cooling (transient time) and the number of glass plates crushed.

[0028]

[Table 1]

As shown in the table, when the mist cooling is added regardless of whether the plate thickness is 5 mm or 3.5 mm, the transition time is shorter (0.1%) than that when only the air cooling is performed.
The number of crushes is increasing. The crushing number is the number of fragments existing in a 5 cm square when the glass plate is crushed, and generally, the higher the crushing number, the higher the strength. When the transition time becomes long and is 0.6 seconds, the number of fractures is smaller than that when only air cooling is performed. This is because the temperature difference between the outside (surface) and the inside of the glass plate caused by the mist cooling is eliminated (reheat) and the temperature of the entire glass plate is lowered, so that the effect of improving the strength by cooling cannot be obtained. Once reheated, the meaning of mist cooling is lost.

Therefore, if the time until the air cooling starts after the mist cooling is shortened (at least 0.5 seconds or less)
The glass plate can be cooled without reheating, and the glass plate can be strengthened by effectively utilizing the large cooling capacity of mist cooling. Reheat also occurs when the cooling capacity of air cooling after mist cooling is low.
Therefore, in order to avoid such reheat, the air cooling capacity when used together with the mist cooling is converted to a heat transfer coefficient for a glass plate having a plate thickness of 2 to 5 mm and is 75 to 100% when only air cooling is performed. A cooling capacity of 95% is required. Further, the mist cooling does not have the same cooling capacity uniformly, and may be gradually lowered as the glass plate passes, or mist cooling may be performed by subdividing the mist cooling part and changing the cooling capacity for each section. Good.

FIG. 2 is a schematic view of a cooling device according to another embodiment. As shown, in the case of this cooling device, the glass plate 1
Is placed on the carrying device 13 and carried. Carrier 1
3 comprises a cooling ring 14 at the tip of the arm 15 and a drive unit 16 at the base of the arm. The cooling ring 14 has the shape of a ring that holds the peripheral edge of the glass plate 1 in correspondence with the shape of the glass plate 1. In the example of the figure, it has a rectangular ring shape. This cooling ring 1
The glass plate 1 placed on the sheet 4 is conveyed in the arrow L direction by the conveying device 13.

The glass plate 1 is similar to the above-described example of FIG.
Cooling is strengthened by passing through the mist cooling section 4 and the air cooling section 5 of the cooling device 3. By using such a cooling ring 14, batch processing can be performed in which the glass plates 1 are stopped one by one and cooled. In the case of batch processing, for example, mist cooling is performed while passing through the mist cooling unit 4, the mist cooling is continuously carried to the air cooling unit 5, and the mist cooling unit 4 is temporarily stopped here and air cooling is performed in the stopped state. Alternatively, both the mist cooling unit 4 and the air cooling unit 5 are sized so that the entire glass plate can be covered with the glass plate 1 stopped, and the mist cooling is performed so that the stopped glass plate entire surface can be cooled by the mist nozzle 6 and the air nozzle 7. The nozzles 6 and 7 may be arranged over the entire portion 4 and the air cooling portion 5, respectively.

In the case of batch processing, the glass plate 1 is conveyed to the mist cooling unit 4 in the mist jetting state and allowed to pass without stopping, and then the glass plate is transferred to the air cooling unit 5. Air cooling may be performed. In this way, mist cooling is performed in the shortest time, and the mist cooling unit 4
The time to stay in becomes shorter. As a result, it is possible to reduce the risk that the excessive mist condensed in the mist nozzle on the upper side of the glass plate drops and the glass plate is damaged.

Table 2 is a table showing optimum conditions for mist cooling.

[0035]

[Table 2]

When the glass plate is subjected to the above-described mist cooling
In this case, it is desirable to carry out under the conditions shown in Table 2. example
For example, the temperature of the glass plate before the start of cooling is 680 ° C and the plate thickness is
In case of 3.5 mm, the amount of mist supplied from the mist cooling part
1.1-1.4kg / sec / m²As the mist supply time
Assuming mist cooling capacity is 760W for 0.2-0.4sec.
/ m ²K, and the air cooling capacity of the air cooling unit is 310 to 360
W / m²Adjust to K. The optimum conditions shown in this table
If the cooling capacity is low, sufficient strength cannot be obtained, and conversely, if it is high,
The glass plate may be damaged by thermal shock. From the table
As you can see, as the temperature of the glass plate decreases
The product of feed rate and mist feed time must be reduced.
Absent. Also, the product of mist supply amount and mist supply time is the same.
If so, it is free to change each other's numbers.

If the excess mist comes into contact with the glass plate to locally increase the heat transfer coefficient, the glass plate may be damaged by heat shock. Therefore, the average particle size of the supplied mist is 20 μm or less. However, it is desirable that particles having a large particle size are not included.

FIG. 3 is a schematic view of an embodiment in which a shield plate is provided in the mist cooling section. As shown in the figure, between the mist cooling units 4 arranged vertically opposite to each other, shield plates 17 for covering the left and right edge portions with respect to the transport direction K of the transported glass plate 1 are vertically provided (four in total). As a result, when the glass plate 1 transported in the direction of arrow K by the transport roller 2 is covered with the shielding plate 17 at the edge portion during mist cooling, the mist does not adhere. Therefore, it is possible to prevent excessive cooling of the edge portion, which is the starting point of cracking of the glass plate, and reduce the risk of breakage of the glass plate. In addition, the upper shield plate is 100
By heating above m ° C, the mist adhering to the shielding plate can be evaporated and removed, and dripping onto the glass plate can be prevented.

FIG. 4 is an explanatory view of another example of the edge protection method by the mist cooling section. In this example, the front and rear edges are protected with respect to the conveying direction of the rectangular glass plate.
As shown in (A), when the glass plate 1 is transported in the direction of arrow K by the transport roller 2, the front edge 1a at the front end of the glass plate in the transport direction passes through the photoelectric sensor 18 provided at a predetermined position. It is detected by Sensor 18
When the glass plate 1 is detected by the control circuit 1 connected to it
9 calculates the time during which the front edge 1a of the glass plate 1 passes through the mist cooling unit 4 and is further conveyed by a predetermined distance from the conveyance speed of the glass plate 1.

The controller sets this time in a timer (not shown). The glass plate 1 is conveyed as indicated by an arrow K without performing mist injection until the timer time is reached.
After the timer time has elapsed, the front edge 1a of the glass plate 1
As shown in (B), the drive circuit 20 is actuated when the position where the mist cooling 4 is further conveyed for a predetermined distance is reached, the electromagnetic valve 21 is opened, and mist injection is started as shown in the same figure. To do. Therefore, mist is not jetted to the front end edge 1a and its vicinity.

Subsequently, as shown in (C), the glass plate 1 is continuously conveyed, and a mist is jetted to the glass plate 1. At this time, the air cooling unit 5 injects air to cool the air as described above. This air injection may be started at or near the time when the front edge 1a of the glass sheet 1 reaches the air cooling section 5, or may be continuously blown from the beginning.

The mist injection is performed by the rear edge 1 of the glass plate 1.
It is stopped a predetermined distance before b reaches the mist injection region.
This is because the drive circuit 2 is controlled by the control circuit 19 by detecting the glass plate or setting the timer time from the start of mist injection.
This can be done by closing the solenoid valve 21 via 0. As a result, mist is not jetted near the rear edge 1b of the glass plate 1.

Subsequently, as shown in (D), the glass plate 1 is conveyed while passing only through the air cooling and passed through the cooling device 3. In this way, the mist injection to the front and rear edge portions with respect to the transport direction of the glass sheet 1 is stopped, whereby excessive cooling of the edge portion, which is the starting point of cracking of the glass sheet, is prevented, and the glass sheet may be damaged. It can be reduced.

By using the front and rear edge protection structure of the glass plate shown in this figure together with the shield plate for protecting the left and right edge parts shown in FIG. 3, the front, rear, left and right edge parts of the glass plate are protected. Therefore, damage to the glass plate due to excessive mist cooling can be prevented more effectively.

FIG. 5 is a schematic view of a cooling device equipped with an intake duct. As shown in the drawing, a plurality of intake ducts 22 (three in the figure only on the upper side) are attached near the mist cooling section 4 of the cooling device 3 both above and below the glass conveying surface. The intake duct 22 has a suction port 22b at the tip of the flexible hose 22a.
It is equipped with. Thereby, the mist scattered at the time of cooling the mist of the glass plate 1 can be sucked and removed, and the excess mist can be prevented from adhering to the apparatus. At this time, the area around the suction port 22b of the intake duct 22 is set to 1
By heating to above 00 ° C, the mist adhering to the vicinity of the suction port 22b can be evaporated and removed, and the generation of excess mist can be prevented more reliably.

Further, the transport roller 2 near the mist cooling section 4
In addition, for example, by incorporating an electric heater and heating at 100 ° C. or higher, the mist adhering to the transport roller 2 can be evaporated and removed while the glass plate 1 is being cooled.

In the case of the batch type using the transport ring (FIG. 2), the surplus mist adhering to the ring is evaporated by heating the surface of the ring to 100 ° C. or more, and the glass plate is cracked by the heat shock when the glass plate is mounted. Can be prevented.

Further, since mist may flow into the air cooling section, excess mist can be removed by heating the surface of the air nozzle 7 to 100 ° C. or higher. In this case, when the air cooling unit 5 is composed of a chamber, the plate material of the ejection surface on which the ejection holes are formed is heated by, for example, an electric heater. In addition, it is desirable that air is ejected when the glass plate is not present in the air cooling unit to discharge the water adhering to the nozzle and the peripheral portion to the outside of the apparatus. Alternatively, a structure may be used in which an air blower is provided in the air cooling unit and the surplus mist is blown off during the air cooling of the glass plate.

Further, the amount of mist supplied from the mist cooling section 4 can be minimized as much as possible to reduce the generation of surplus mist. At this time, in addition to the air for atomizing the water from the mist nozzle, pattern forming air capable of arbitrarily setting the mist pattern may be supplied.

FIG. 6 is a schematic view of a cooling device equipped with a scraper. As illustrated, when the glass plate 1 is conveyed to the mist cooling section in the direction of arrow K, the mist 23 is ejected from the mist nozzle 9 (only the lower mist nozzle is shown in the drawing). The transport roller 2 is made of a material having high water repellency,
The scraper 24 abuts on the lower side thereof. When the mist is cooled, excess mist adhering to the transport roller 2
It moves downward with the rotation of (arrow R). At this time, the scraper 24 scrapes off the excess mist, wipes it off or sucks it off. As a result, it is possible to prevent the excess mist attached to the transport roller 2 from attaching to the glass plate 1 and damaging the glass plate 1 due to heat shock. The scraper 24 may be made of a material having the same high water repellency as that of the carrying roller or rubber when scraping off the mist, or may be a cloth or sponge when wiping or sucking.

Table 3 compares the effects of mist cooling and air cooling according to the present invention on a glass plate having a plate thickness of 5 mm, as compared with the case of only air cooling.

[0052]

[Table 3]

As shown in Table 3, the glass plate was cooled and strengthened by both mist cooling and air cooling so that the glass plate had the same crushing number (that is, the same strength) as the glass plate strengthened only by air cooling. In this case, when the plate thickness is 5 mm, the heat transfer coefficient reduction rate is 9.3%, and the blower shaft power reduction rate of the blower that supplies the compressed air for air cooling is 35%.
Therefore, by adding the mist cooling to strengthen the glass plate, the cooling effect is increased and the power consumption is reduced, so that resource saving can be achieved. Table 4 shows the details of the experimental conditions in Table 3 including the case of other plate thicknesses.

[0054]

[Table 4]

The experimental conditions in Table 3 are the plate thickness in Table 4 of 5 mm.
This is for a glass plate temperature of 680 ° C. As shown in Table 4, by adding the mist cooling of the present invention to each plate thickness, the cooling action is improved (improvement effect) and the power consumption is reduced (blower energy saving rate), as compared with the conventional air cooling only. ). The improvement effect is the reduction rate of the heat transfer coefficient of air cooling required to obtain the same number of fractures, and the blower energy saving rate is the improvement effect of the axial power of the blower that supplies cooling air. It is converted into a reduction rate. The measure against breakage is to adjust the injection timing so that the mist does not hit the front and rear edges of the glass (Fig. 4).
In this way, when cooling and strengthening the glass sheet, resource saving can be contributed by additionally performing air-cooling with mist cooling provided with measures against breakage of the present invention.

[0056]

As described above, according to the present invention, the mist cooling and the air cooling are used together, and the time from the end of the mist cooling to the start of the air cooling is set to 0.5 seconds or less. It is possible to prevent reheating and effectively utilize mist cooling to strengthen the glass plate.
Further, excessive cooling due to mist cooling can be suppressed by air cooling, and evaporation of excess mist can be promoted to prevent damage to the glass plate due to dropping of water droplets on the glass surface.
When the mist is cooled, the edge of the glass is protected to prevent excessive mist cooling, and by cooling under the optimum conditions, it is possible to strengthen the thin glass plate with certainty and save energy. it can.

Further, since an excess mist can be removed by providing an intake duct near the mist cooling section, heating the conveying roller, or providing a scraper, the glass plate is prevented from being damaged by dropping the excess mist. You can

[Brief description of drawings]

FIG. 1 is a schematic view of a cooling intensifying device using a conveyance roller.

FIG. 2 is a schematic view of a cooling device according to another embodiment.

FIG. 3 is a schematic view of an embodiment in which a cooling device is provided with a shielding plate.

FIG. 4 is an explanatory diagram of another example of an edge protection method using a mist cooling unit.

FIG. 5 is a schematic view of a cooling device with an intake duct attached.

FIG. 6 is a schematic view of a cooling device equipped with a scraper.

[Explanation of symbols]

1: glass plate, 1a: front edge, 1b: rear edge,
2: transport rollers, 3: cooling device, 4: mist cooling unit,
5: Air cooling unit, 6: Mist nozzle, 7: Air nozzle,
8: Air chamber, 13: Transfer device, 14: Ring, 1
5: arm, 16: drive part, 17: shield plate, 18: sensor, 19: control circuit, 20: drive circuit, 21: solenoid valve, 22: intake duct, 22a: flexible hose,
22b: suction port, 23: mist, 24: scraper,
25: Conveyor.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3L044 AA04 BA05 CA04 DA01 DB01                       DD03 FA06 KA04                 4G015 CA03 CA05 CA08 CB01 CC01

Claims (8)

[Claims] 1. A mist for a glass plate using a glass plate cooling device comprising a mist cooling part for ejecting mist-like water, an air cooling part for ejecting air, and a glass plate conveying means for conveying a glass plate. A glass plate cooling strengthening method of cooling air after cooling, wherein the period from the end of mist cooling by the mist cooling unit to the start of air cooling by the air cooling unit is within 0.5 seconds. How to strengthen. 2. The glass plate conveying means is constituted by arranging a plurality of cylindrical conveying rollers, and the glass plates are placed on the conveying rollers so that the plurality of glass plates can be continuously cooled by the mist cooling unit and air cooling. The glass plate cooling and strengthening method according to claim 1, wherein the parts are sequentially passed to cool. 3. The glass plate conveying means is provided with a cooling ring corresponding to the shape of the glass plate, the glass plates are placed on the cooling ring, and the glass plates are placed one by one in the mist cooling section and the air cooling section. The glass plate cooling and strengthening method according to claim 1, wherein the glass plate is cooled by being conveyed in order. 4. The glass plate cooling / strengthening method according to claim 1, wherein the mist cooling unit cools the glass plate while shielding the left and right edge portions in the conveying direction of the glass plate. 5. The mist injection is stopped with respect to the glass sheet passing through the mist cooling section at the timing when the front and rear edge portions in the transport direction pass through the mist cooling section. The glass plate cooling and tempering method as described in 2, 3, or 4. 6. The mist cooling of the glass plate is performed by providing an intake duct near the mist cooling section and sucking the mist by the intake duct.
The method for cooling and strengthening a glass plate according to any one of 1. 7. The mist cooling of the glass plate is performed while heating the peripheral devices such as the transport roller and the air cooling unit in the vicinity of the mist cooling unit or in the vicinity thereof. 6. The glass plate cooling and strengthening method according to any one of 6 above. 8. A scraper for removing water adhering to the conveying roller by contacting the conveying roller in the mist cooling section or in the vicinity thereof, according to claim 1, 2, or 4 to 6. The method for strengthening a glass plate according to one item.