JP2001039724A - Bending method for glass sheet and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus suitable for bending of glass sheets, such as side windshields for vehicles in particular, having a small bending radius, relating to a method and an apparatus for bending the heated glass sheets by blowing high-temperature jet gaseous streams to the glass sheets from their rear surfaces and pressing the rear surfaces onto a bending die. SOLUTION: In the method for bending the heated glass sheet 1 by floating the glass sheet by the high-temperature jet gaseous streams and pressing the glass sheet to the rear surface of the bending die 4 disposed above, plural nozzles 11 for injecting the jet streams to the rear surface of the glass sheet are disposed between transporting rolls 5 and the nozzles arranged from the portions where the bending radius is small toward the portions near the end sides in compliance with the bending die of the glass sheet are brought near to the glass sheet surface from the other nozzles. The nozzles are formed as a tiltable type to prevent the interference with the transporting rolls during the putting in and out of the nozzles at the time of nozzle exchange. The front ends of the nozzles are provided with plural jet stream discharge holes so that the jet streams are diffused to the rear surface of the glass sheet and are uniformly injected to the rear surface of the glass sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for blowing a high-temperature jet gas stream from a lower surface onto a heated glass sheet and pressing the glass plate against a lower surface of a bending mold, and particularly to a method for bending a side window glass for a vehicle. It is suitable for bending a glass plate with a small radius.

[0002]

2. Description of the Related Art A side window glass for a vehicle is often provided with a slight curvature on a rear window side in order to match a vehicle body.

[0003] Generally, such a glass sheet is formed by a gas hearth method in which the glass sheet is bent while being conveyed on a refractory having a curvature, or a glass sheet is supported by a hanging tool and heated to a temperature close to a softening temperature. Pressing method using a press mold, or heating the glass plate while transporting the inside of the heating furnace by a transport roll, stopping the glass plate once in the latter half of the heating furnace, and then lowering the transport roll to the bending die arranged on the upper part There is known a so-called quick sag bend method in which a glass plate is pressed against the lower surface of a bending mold by high-temperature jet air and bent.

Among the various methods described above, in the quick sag bend method, when manufacturing a vehicle side window glass or the like having a small bending radius, a high-temperature jet air is locally blown onto a small bending radius to obtain a desired shape. Gaining is done conventionally.

Patent No. 251 discloses a quick sag bend method.
No. 1066 discloses that the flow rate of a partial hot gas flow flowing radially from the center to the outside along the surface of the glass sheet at least at the peripheral edge of the glass sheet is selected. A method and apparatus are disclosed wherein the static pressure component of the gas flow is increased at the peripheral edge of the glass sheet by being reduced by a blocking wall disposed in the flow path of the flow.

[0006]

The gas hearth method described above is a technique generally used for bending a two-dimensional shape, and it is difficult to cope with a three-dimensional bent shape required in design.

Further, in the pressing method, traces of hanging tools for suspending the glass plate remain on the glass plate, causing a problem in appearance, and forming a resin frame on a peripheral portion of the glass plate bent in a later process. Sometimes there was a problem with strength.

Further, in the quick sag bend method,
When manufacturing side window glass for vehicles with small bending radius, if high-temperature jet air is locally blown on the small bending radius of the glass plate, the softened glass plate deforms and wavy distortion occurs. It is effective to use a diffusion-type lift jet nozzle to prevent this distortion.However, the distance between the rolls is as small as several tens of millimeters, and the gap between the rolls is small. It is difficult to blow uniform air on
In addition, it is necessary to allow the lift jet to be put in and out of the furnace at the time of changing the product shape.

Furthermore, in the invention disclosed in Japanese Patent No. 2511066, which is a quick sag bend method, a desired shape cannot be obtained when the bending radius is small because the pressure of the high-temperature gas is low. Further, when the pressure of the high-temperature gas is increased, there is a problem that the glass sheet softened by the pressure is deformed, and a wave-like distortion is generated, thereby significantly lowering the quality of the product.

[0010]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, that is, when manufacturing a window glass for a vehicle by the quick sag bend method, a high-temperature jet stream is uniformly blown on a portion having a small bending radius. A heated glass plate is floated by a high-temperature jet stream, and it is pressed against the lower surface of a bending mold provided above, with the aim of being able to move it in and out of the furnace without distortion and without causing distortion. In the method, a plurality of nozzles for jetting a jet stream on the lower surface of the glass sheet are provided between the transport rolls, and the position from the small radius of the bent radius of the glass sheet to the vicinity of the end side in accordance with the shape of the lower surface of the bending die of the glass sheet. The tip of the nozzle placed in the nozzle can be closer to the glass plate surface than the tip of other nozzles, and it does not interfere with the transport roll when taking in and out when replacing the nozzle. A method of forming a glass plate by forming a plurality of jet flow discharge holes at the tip of the nozzle and diffusing the jet flow to the lower surface of the glass plate so that the jet flow is uniformly jetted to the lower surface of the glass plate. In the apparatus which conveys the inside of the heating furnace, floats the glass plate stopped at a predetermined position by a high-temperature jet stream, and presses and presses against a lower surface of a bending mold disposed above the glass plate to bend and form,
A plurality of fixed nozzles that jet a jet stream over the entire lower surface of the glass plate on a mount that can be inserted and removed, and fall down on the mount to a position from the small bent radius of the glass plate to the vicinity of the end side It consists of a plurality of freely displaceable nozzles, and when standing up, the tip of the tip of the retractable nozzle is located between the transfer rolls and close to the lower surface of the glass plate. To approach
The present invention provides a glass sheet bending apparatus having a mechanism in which a tiltable nozzle is tilted when the gantry is taken in and out, and the mechanism is positioned below a transport roll.

[0011] A plurality of discharge holes are provided at the tip of the nozzle, or the plurality of jet flow discharge holes formed in the nozzle portion have a fan-like shape in which the discharge direction angle is outwardly widened. It is desirable that the tilting angle of the tilting nozzle can be adjusted.

DETAILED DESCRIPTION OF THE INVENTION In the present invention, a flat glass plate 1 which has reached a softening point is stopped at a predetermined position while being conveyed in a heating and bending furnace 3 by a conveying roll 5, and is shown in FIGS. Nozzles 11,..., 1 provided below
The glass plate 1 is floated by jetting a high-temperature jet stream according to 2,..., And a glass plate is disposed on the lower surface of a bending mold (mold) 4 which is disposed above the floated glass plate 1 and is curved downward and convexly. 1 is a method and an apparatus for manufacturing a curved glass 1 which is pressed against a lower surface of a bending mold 4 to conform to the shape of the lower surface of the bending mold 4.

A plurality of suction holes 4 are provided on the lower surface of the bending mold 4.
are provided, and the glass plate 1 is sucked to the lower surface of the bending mold 4 by the suction holes 4a,.

The plurality of nozzles include a plurality of fixed nozzles 11 for jetting a jet stream upward substantially over the entire lower surface of the glass plate 1, and a portion of the glass plate 1 from a small bent radius to an end side. A plurality of retractable nozzles 12, 12,... Having a mechanism capable of causing the tip of the nozzle to approach the lower surface of the glass plate 1 and moving up and down, and each of the nozzles 11, 12 is provided with high-temperature jet air. It is connected to supply pipes 15 and 16.

The flat glass sheet 1 softened by the heating is floated by jet air jetted upward by a plurality of fixed nozzles 11, 11,... And collapsible nozzles 12, 12,. The jet pressure of the jet air is lower than that of the fixed nozzle because the tip of the retractable nozzle has a plurality of discharge holes.

Further, since the foldable nozzle suppresses the jet pressure of jet air, it is provided so as to be closer to the glass plate than the fixed type nozzle.

500 to 10 such as a side window glass plate for a vehicle
In the formation of a curved glass plate requiring a normal bending radius of about 00 mm, the distance between the tip of the fixed nozzle 11 and the apex of the transport roll 5 is 70 to 80 mm, as shown by the symbol n in FIG. However, in the formation of a curved glass plate that requires a small bent radius of about 250 to 500 mm depending on the shape of the vehicle, the tip of the discharge hole 13 of the retractable nozzle 12 and the top of the transport roll 5 are generally used. It is desirable that the distance between the parts is reduced by about 5 to 30 mm as shown by the symbol m in FIG.

The air pipes 15 and 16 are connected to the heating and bending furnace 3.
Is provided on a gantry 10 which can be horizontally moved in and out of the furnace from the side wall of the bending die 4.

The retractable nozzle 12 is provided such that, when standing, the tip of the nozzle 12 is located very close to the lower surface of the glass plate 1 between the transport rolls 5, 5.
Was made to approach the glass plate 1.

When the gantry 10 supporting the nozzle 12 is moved in and out of the furnace between the inside and the outside of the furnace, the foldable nozzle 12 is tilted down so that the transfer roll 5 and the nozzle 12 do not come into contact with each other. So that it is in the lower position.

It is preferable that the tilting direction of the foldable nozzle 12 be along the axis of the transport roll 5 so that the interval between the transport rolls 5 can be narrowed. If it is set down, it is necessary to widen the interval between the transport rolls 5 so as not to contact the transport rolls 5, and it becomes difficult to support the softened glass plate 1, which is not preferable.

Further, the foldable nozzle 12 provided from the portion of the glass plate 1 where the bending radius is small to the vicinity of the end portion is provided.
Has a discharge section having a plurality of discharge holes 13, 13,..., And has a fan shape in which the discharge direction angle of each discharge hole 13 extends outward. This is to prevent the jetted high-temperature jet air from diffusing upward and not locally jetting strongly to the lower surface of the glass plate 1. The nozzle 12 is moved closer to the lower surface of the glass plate, and high-pressure air is applied to the lower surface of the glass plate 1. This is to prevent generation of wavy distortion which is likely to occur when spraying.

That is, it is located at an intermediate portion of the transport roll 5,
Discharge hole 1 at tip of retractable nozzle 12 protruding upward
Are provided in a row in parallel with the conveying direction of the glass plate 1 so that the discharge angles of the respective discharge holes 13 are different, and the discharge holes 13 are expanded outward. With the fan shape, the high-temperature jet air spreads to a portion close to the transport roll 5 and further branches into a plurality of discharge holes 13 and is jetted. Therefore, the pressure of the jet air to be jetted is dispersed and too strong. However, it is uniformly diffused in a small portion of the glass plate 1 where the bending radius is small.

The tilting angle of the tiltable nozzle 12 is connected to a tilting shaft, and by operating the handle 14 from outside the furnace, the tilting angle of the tiltable nozzle 12 is changed from a substantially horizontal state to a substantially vertical state. Adjustable.

A method for bending the glass sheet 1 using the apparatus for bending the glass sheet 1 having the nozzle 12 will be described.

When the flat glass sheet 1 conveyed while heating the inside of the heating bending furnace 3 and reaching the softening point is stopped at a predetermined position, as shown in FIG. A plurality of fixed nozzles 1 provided thereunder
The glass plate 1 floats by the high-temperature jet air jetted upward from 1.

As shown in FIGS. 2 and 3, the flat glass plate 1 is pressed against the convex lower surface of the bending die 4 provided above by jet air from below, and is pressed against the lower surface of the bending die 4. The lower surface of the bending die 4 is sucked and held by the plurality of suction holes provided. However, since the glass plate 1 is softened, the glass plate 1 is curved along the curved surface shape of the lower surface of the bending die 4.

In particular, for the portion of the glass plate 1 where the bending radius is small, in order to improve the bending accuracy, the fixed nozzle 11 is arranged so that the jet air is injected from the portion to the vicinity of the end. Another nozzle 12 is brought close to the lower surface of the portion of the glass plate 1.

In the formation of a curved glass plate requiring a small curved round portion of about 250 to 500 mm depending on the shape of the vehicle or the like, the nozzle that is close to the small portion of the curved round portion is provided with a nozzle as shown by the symbol m in FIG. The distance from the tip to the top of the transport roll 5 is about 5 to 30 mm,
Further, a plurality of jet air discharge holes 13, 13,... Provided at the tip of the nozzle are provided in a fan shape so as to expand toward the outside, and high-temperature jet air is formed on the lower surface of the glass plate 1 in a curved manner. The spray is uniformly and diffused from the small portion to the vicinity of the end.

When the glass plate 1 is brought into close contact with the lower surface of the bending die 4 and bent into a desired shape after a certain period of time, the glass plate 1 is cold-loaded from the side to the lower portion of the glass plate 1 sucked and held by the bending die 4. A receiving frame of a curved high-temperature glass plate 1 called a ring 6 is inserted, and immediately after the insertion of the receiving frame, the glass plate 1 formed by bending by releasing suction of the bending mold 4 and stopping jet air from below is formed by a cold ring. 6 and is conveyed together with the cold ring 6 to the next step of quenching and tempering step 15 where it is quenched and tempered to obtain tempered glass curved into a desired shape.

The nozzle 12 for injecting high-temperature jet air into the small portion of the bending radius is of a foldable type, and the nozzle 1 is formed in accordance with various curved shapes of the glass plate 1 to be bent.
At the time of replacing the gantry 10 provided with 2 and 11, it is lowered to a height that does not interfere with the transfer rolls 5 in the furnace, that is, a position lower than the lower surface of the transfer rolls 5 so that it can be easily taken in and out of the furnace. Let them in and out.

As described above, since the tip of the nozzle 12 is brought very close to the desired position on the lower surface of the glass plate 1 where the bending radius is small, the glass plate 1 can be bent accurately even if there is a small bending radius. Can be molded.

Further, since the nozzle 12 is of a retractable type, even when the tip of the nozzle 12 is very close to the lower surface position of the glass plate 1 between the transport rolls 5, the nozzle 12 can be easily taken in and out when the nozzle 12 is replaced. Now you can do it.

Here, the reason why the discharge hole 13 of the retractable nozzle 12 and the top of the transport roll 5, that is, the lower surface of the glass plate 1 are brought extremely close to each other is that the discharge hole 1 at the tip of the retractable nozzle 12
This is because the glass plate 1 is floated by the high-temperature jet air from 3 to increase the pressure when the glass plate 1 is bent and to prevent the glass plate 1 from being deformed by the jet pressure of the air.

The fixed nozzle 11, the retractable nozzle 12, the air pipe, and the like are made of metal because they are provided in a furnace at a high temperature enough to soften the glass plate 1.

It is preferable that the distance between the top of the transport roll 5 for transporting the glass sheet 1 and the tip of the retractable nozzle 12 is 5 to 30 mm. If the distance is less than 5 mm, the glass sheet 1 will be distorted. This is because the effect cannot be obtained if it exceeds 30 mm.

Here, the gantry 10 having the nozzles 11 and 12 shown in FIG. 2 is inserted into the lower part of the transport roll 5 from the end of the heating bending furnace 4 by an opening / closing door provided on a side wall.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The nozzles 11 and 12 for injecting high-temperature gas need to be moved in and out of the furnace when changing the shape of the curved glass plate 1 to be manufactured. So as not to contact the transport roll 5
As shown in FIG. 5, 10 to 10 mm from the lower end of the transport roll 5 in the furnace.
The nozzle 11 was arranged at a lower position of about 15 mm. For this reason, the distance from the tip of the nozzle 11 to the lower surface of the glass plate 1 on the transport roll 5 is about 70 to 75 mm, and the glass plate 1
Cannot be brought close to the nozzle 11.

Further, in order to cause the nozzle 12 for jetting high-temperature jet air to approach the lower surface of the glass plate 1 and jet the nozzle, the nozzle 12 is put into the furnace with the nozzle 12 turned down, and then the nozzle 12 is operated by operating the handle 14 from outside the furnace. And the tip of the nozzle 12 is arranged between the transport rolls 5 so as to be close to the lower surface of the glass plate 1 to form a retractable nozzle 12.

A plurality of discharge holes 13, 13,... So that high-temperature jet air injected from the nozzle 12 is diffused.
Was provided radially.

As shown in FIG. 6, for example, as shown in FIG. 6, five discharge holes 13 are provided on the straight line of the plurality of discharge holes 13, 13,. As shown in FIG. 7A, it can be provided in a cross shape.
As shown in (b), it may be provided in a central part and its periphery in a plurality of directions, and may be formed according to the shape of the glass sheet 1 to be bent.

The shape of the tip surface of the retractable nozzle 12 is not limited to a rectangular shape, but may be a circular shape, a flat shape, or a curved convex shape having a convex shape on the upper side.

In this embodiment, the angle of the nozzle is 90 degrees.
The hot gas is blown in a direction perpendicular to the surface of the flat glass plate 1, but the handle 14 provided outside the furnace is shown in the drawing so that the nozzle angle can be adjusted according to the curved shape of the glass plate 1. A stopper or the like that does not need to be attached can also be attached.

Although the preferred embodiment has been described above, the present invention is not limited to this, and various applications can be considered.

[0044]

According to the present invention, a glass having a small bending radius such as a side window glass of an automobile can be uniformly blended into a mold, a desired curvature shape can be obtained, and the bending radius of a glass plate, which has been difficult in the past, is small. It is possible to obtain a very high quality product having a desired shape with good quality by eliminating the wavy distortion of the portion.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a bending furnace including a peripheral device of the present invention.

FIG. 2 is a perspective view of a bending apparatus according to the present invention.

FIG. 3 is a front view showing the positional relationship between the bending apparatus of the present invention and a bending die.

FIG. 4 is a side view showing a positional relationship between the foldable nozzle and a transport roll.

FIG. 5 is a side view showing a positional relationship between a fixed nozzle and a transport roll.

FIG. 6 is a perspective view showing the shape of a discharge hole at the tip of the retractable nozzle of the present invention.

FIGS. 7A and 7B are perspective views showing a modified example of the shape of the discharge hole at the tip of the retractable nozzle of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass plate 2 Bending apparatus 3 Heating bending furnace 4 Bending mold (mold) 5 Conveyance roll 6 Cold ring 10 Lower gantry 11 Fixed nozzle 12 Folding nozzle 13 Discharge hole 14 Handle 15 Rapid cooling strengthening process

Claims (2)

[Claims] 1. A method of floating a heated glass sheet by a high-temperature jet flow and pressing and bending the glass sheet against a lower surface of a bending mold provided above, wherein a plurality of nozzles for jetting a jet flow on the lower surface of the glass plate are interposed between conveying rolls. The tip of the nozzle arranged in a position from the small portion of the bending radius of the glass plate to the vicinity of the end side in accordance with the lower surface shape of the bending die of the glass plate is closer to the glass plate surface than the tip of the other nozzles In addition, it is foldable so that it does not interfere with the transport roll when taking in and out when replacing the nozzle, and multiple jet flow discharge holes are provided at the tip of the nozzle and diffused on the lower surface of the glass plate, so that the jet flow is uniform on the lower surface of the glass plate A method for bending a glass sheet, characterized in that the glass sheet is injected into the glass. 2. An apparatus which is conveyed in a heating furnace by a conveying roll, floats a glass plate stopped at a predetermined position by a high-temperature jet stream, and presses the glass plate against a lower surface of a bending mold disposed above the glass plate to bend and form. In, a plurality of fixed nozzles for jetting a jet stream over the entire lower surface of the glass plate, on the mount that can be freely inserted and removed, and the mount on the mount at a position from a small portion of the bent radius of the glass plate to near the end side. It consists of a plurality of retractable nozzles that can be freely raised and lowered, and when standing up, the tip of the retractable nozzle is located between the transfer rolls and close to the lower surface of the glass plate. A bend forming apparatus for a glass sheet, wherein the mechanism is arranged so as to be close to the glass sheet, and a mechanism for tilting the tiltable nozzle down to a position below the transport roll when the mount is taken in and out.