JP2001158631A - Method for curving and molding glass plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniform the pressure distribution of air jetted on the surface portion of a glass plate and prevent the optical distortion on molding, when the glass plate is curved and molded into a window glass for an automobile and even when the glass plate is sufficiently not arranged with carrying rolls on the end side of the glass plate crossing carrying rolls for carrying the glass plate. SOLUTION: This method for curving and molding the glass plate, comprising floating a thermally softened glass plate with high temperature jets and pressing the floated glass plate to the lower surface of an upward curved mold, characterized by disposing inclined nozzles having the jetting directions in the obliquely upward directions on the upward or downward sides of nozzles which have the jetting directions in the vertical direction and are disposed at the approximately central positions between the carrying rolls just below the edges of the glass plate and below the mutually facing two edges of the carried glass plate in the carrying direction, and jetting air from the inclined nozzles through spaces between the carrying rolls to supplement the low pressure portions of air jetted from the vertically directed nozzles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of blowing a high-temperature jet air stream onto a lower surface of a heated glass sheet to float the glass sheet.
The present invention relates to a method for bending a glass plate by pressing the glass plate against a lower surface of a bending mold.

[0002]

2. Description of the Related Art A window glass for a vehicle is often curved in order to match a shape of a vehicle body. Generally, a method of forming such a window glass is to use a refractory having a curvature. The gas hearth method of bending while transporting the top, the press method of forming a glass plate with a press mold after heating the glass plate to near the softening temperature by supporting it with a hanging tool, or floating the glass plate softened in a heating furnace by jet air, There is known a method called a quick sag bend method in which a sheet is pressed against a bending mold and bent.

[0003] Of the above-mentioned various methods, the quick sag bend method is widely used when manufacturing a rear window glass or a side window glass. More specifically, a quick sag bend method is performed while a glass sheet is transported by a transport roll in a heating furnace. Heated and softened, a flat glass plate stopped at a predetermined position with a bending mold in the upper part of the heating furnace, floated by high-temperature jet air jetted upward from a nozzle arranged below the transport roll, This is a method in which a softened glass plate is pressed against a curved surface of a lower surface of a bending die disposed on an upper portion thereof to be bent.

As the above-mentioned nozzle for floating the glass plate, a nozzle called a direct injection type nozzle or an aspirator type nozzle has been often used.

The direct injection nozzle has a tapered cylindrical tip, and jets jet air from its center.

The aspirator type nozzle is formed by screwing a large-diameter cylindrical portion with a tapered distal end portion as an outer shape. A nozzle for providing a circular gap between the inner peripheral surface of the cylindrical outer projection provided and the outer peripheral surface of the small-diameter taper portion, and jetting jet air from the gap.

[0007]

When a glass sheet is bent by the quick sag bend method, the glass sheet is pressed against the lower surface of the bending mold by jet air jetted upward from a nozzle. Since a plurality of transport rolls for transporting the glass sheet are provided between the nozzles, the glass sheet floats and is pressed against the bending mold by jet air jetted from the nozzle provided below the transport roll. In this case, the jet air inevitably passes through between the transport rolls and is jetted upward.

In this case, the pressure distribution of the jet air jetted to the lower surface of the glass plate is such that when a part of the peripheral edge of the glass plate has a positional relationship such that it intersects with the transport roll, the transport is In the vicinity of the edge of the glass plate that intersects with the roll, the jet pressure of the jet air on the glass surface varies depending on the transport roll, and may not be uniform, although the glass plate can be bent relatively close to the desired shape,
Some optical distortion or the like was observed at a portion where the periphery of the glass plate and the longitudinal direction of the transport roll intersect.

On the other hand, when bending a rear window glass or the like for a vehicle, the upper side and the lower side of the substantially trapezoidal glass plate 1 intersect with the longitudinal direction of the transport roll 5 as shown in FIG. Since the bending depth of the wing portion of the two wings of the glass plate 1 is large, the jet air moves away from the nozzle as the two wing portions of the glass plate 1 curve along the bending die, and the jet air is generated even when the wing portion moves away. In order to distribute the nozzles sufficiently on the glass surface, one or more transport rolls 5 on both wings of the glass plate are removed, and measures are taken such as increasing the number of nozzles 20, 20,.

However, since the upper side and the lower side of the glass plate 1 have a positional relationship of intersecting with the transport roll 5 as described above, the nozzle 20 for bending the upper side and the lower side, as shown in FIG. It must be provided between the rolls 5 and 5, and it was difficult to completely eliminate the occurrence of optical distortion even if conditions in the furnace were adjusted.

Further, in the quick sag bend method,
When high-temperature jet air is locally blown on the glass plate surface, there is a problem that the softened glass plate is deformed and undulating optical distortion is likely to occur, and the gap between the rolls is as narrow as tens of millimeters. However, it was difficult to blow uniform air onto the glass surface from the gap.

[0012]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, that is, when manufacturing a window glass for a vehicle by the quick sag bend method, a glass sheet conveyed by a conveyance roll is opposed to a glass sheet conveyed by a conveyance roll. It is an object of the present invention to be able to uniformly blow high-temperature jet air to an edge of a side and to prevent occurrence of optical distortion.

That is, the present invention provides a method for bending a glass sheet in which a glass sheet softened by heating is levitated by a high-temperature jet air flow and pressed against a lower surface of a bending die provided above to bend the glass sheet. A nozzle disposed below the two opposite edges of the glass sheet in the conveying direction may be provided at a position substantially at the center between the conveying rolls immediately below the edge of the glass sheet, and the jetting direction may be provided vertically or upstream of each nozzle position. An oblique nozzle whose oblique direction is directed obliquely upward is provided downstream, and the jet air ejected by the oblique nozzle passes between the transport rolls to compensate for a portion where the air pressure ejected by the vertically oriented nozzle is low. This is a method for forming a bent glass sheet in which the jet air pressure distribution on the glass sheet surface is made uniform.

In the present invention, the upstream oblique nozzle may be an upstream oblique nozzle and the downstream oblique nozzle may be an upstream oblique nozzle and the downstream oblique nozzle may be an obliquely upstream downstream nozzle. Is a method in which the downstream diagonal nozzle is jetted so as to pass between the conveying rolls diagonally upstream and diagonally upward, so that the jetting directions of both oblique nozzles intersect.

Further, the present invention is the above-described method for forming a bent glass sheet, wherein the oblique nozzles are arranged at positions where the jet air jetted by the nozzles do not collide with each other.

[0016]

DETAILED DESCRIPTION OF THE INVENTION As shown in FIG. 1, a flat glass plate 1 which has reached a softening point while being conveyed in a heating and bending furnace by a conveying roll 5 is stopped at a predetermined position in the furnace. A plurality of nozzles that are disposed below the stopped glass plate and ejected upwardly eject high-temperature jet air to float the glass plate 1, and are disposed above the floated glass plate 1. The glass plate 1 is pressed against the lower surface of a bending mold (mold) 4 whose lower surface is curved in a convex shape to manufacture a curved glass plate 1 conforming to the shape of the lower surface of the bending mold 4.

A plurality of suction holes (not shown) are provided on the lower surface of the bending die 4 and communicate with a separately provided suction device (not shown) so that the glass plate 1 can be sucked to the lower surface of the bending die 4. It is to let.

Further, as shown in FIG. 2, the plurality of nozzles are provided with a plurality of nozzles for jetting jet air upward over a peripheral portion of the lower surface of the glass plate 1 and a central region. Regarding the position where the number of attachments is restricted by the transport rolls, that is, the nozzles provided so as to spray on the upper side and the lower side of the glass plate intersecting the longitudinal direction of the transport rolls, for example, a conventionally known aspirator type nozzle 20 is shown in FIG. Arranged as shown.

That is, just below the edge of the glass plate, at substantially the center position between the transport rolls, the injection direction is indicated by an arrow b in the upstream or downstream direction of each nozzle provided vertically upward as shown by an arrow a in FIG. An oblique nozzle directed obliquely upward is provided so that high-temperature jet air ejected by the oblique nozzle passes between the conveying rolls to compensate for a portion of low air pressure ejected by the nozzle oriented vertically. Then, it was arranged so that jet air would be jetted to the two sides facing each other in the direction intersecting with the transport roll transporting the glass plate.

In short, the nozzles that cause the glass sheet 1 conveyed by the transport rolls 5 to jet toward the upper side and the lower side intersecting with the transport rolls 5 are as follows.
The number is limited because it must be provided between, if the air ejection pressure is locally strong, the pressure distribution in this part will be high,
The difference from the portion not exposed to the air becomes large, and the optical distortion tends to be concave.

For this reason, the nozzle 2 which jets vertically upward indicated by an arrow a near the upper edge and the lower edge of the glass plate 1
0 is provided, and a nozzle that injects obliquely upward as indicated by arrow b from upstream or downstream of the nozzle is provided, and the oblique nozzle ejects the jet air ejected by the nozzle that ejects vertically upward at a low pressure. By jetting the jet air, the dispersion of the strong and weak portions of the pressure distribution was reduced, and the air pressure ejected to the surface of the glass plate 1 was dispersed so as to be evenly distributed.

In addition, a plurality of nozzles having a narrow pitch interval are arranged vertically upward so as to jet high-temperature jet air at the two end portions on the opposite sides of the front and rear ends of the glass sheet in the conveying direction. Then, high-temperature jet air was supplied to each nozzle.

That is, the flat glass plate 1 softened by the heating floats by the jet air jetted upward by a plurality of aspirator type nozzles and is pressed against the lower surface of the bending mold 4, but is pressed like the rear window glass. Since the curvature around the two wings of the glass plate 1 is large, the farther from the nozzle as it bends, it is necessary to increase the ejection pressure of the jet air ejected from the nozzle. An aspirator type nozzle is used.

The flat glass plate 1 is pressed against the convex lower surface of the bending die 4 provided above by the jet air from below, and is pressed by a plurality of suction holes provided on the lower surface of the bending die 4. It is sucked and held on the lower surface,
Since the glass plate 1 is softened, it bends along the curved surface shape of the lower surface of the bending die 4.

When the glass plate 1 is brought into close contact with the lower surface of the bending mold 4 and bent into a desired shape after a certain period of time, the glass plate 1 is sucked and held by the bending mold 4 from the side. The glass plate 1 bent by inserting a receiving frame of a curved high-temperature glass plate 1 called a cold ring, releasing the suction of the bending mold 4 immediately after the insertion of the receiving frame, and stopping jet air from below, The glass is dropped on the cold ring, transported together with the cold ring to the next step of quenching and tempering, and quenched and tempered to obtain tempered glass curved into a desired shape.

As described above, at the upper side and the lower side of the glass plate 1 where the pressure of the air jetted by the transport rolls 5 varies, the nozzle 20 for jetting vertically upward as indicated by the arrow a between the transport rolls 5 is provided. The injection pressure of the jet air of the upper side and the lower side of the glass plate 1 is made uniform by the oblique nozzle 20 ′ which is injected obliquely upward as indicated by an arrow b from the upstream or downstream of the nozzle 20 directed vertically upward, and the formed glass plate When the curvature and the reflection image of Comparative Example 1 were compared, the glass sheet formed by the forming method of the glass sheet 1 of the present invention showed a large reverse-warped optical distortion and a pot bottom shape as compared with the case formed by the conventional forming method. Was good without optical distortion.

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

FIGS. 3 and 4 show a side sectional view and a plan view of another embodiment. This means that the upstream diagonal nozzle 20 ′ and the downstream diagonal nozzle 2
0 'is provided. As the respective jet directions of these nozzles 20 ′, 20 ′, the upstream oblique nozzle 20 ′ indicated by arrow b passes obliquely upward on the downstream side, and the downstream oblique nozzle 20 ′ passes obliquely upward on the upstream side between the transport rolls 5. To the lower part of the air pressure jetted by the vertically oriented nozzle 20 to compensate for the jetting of the one or two oblique nozzles 20 ′. The jet air pressure distribution was made uniform.

In this case, the position and the injection angle of the oblique nozzle 20 'are arranged such that the jet air jetted by the oblique nozzle 20' does not collide with each other.

As shown in FIG. 3 and FIG.
The nozzles 20, 20,... that are directed vertically upward are arranged between a, 5b, 5c, 5d, and 5e. Below the transport roll 5b, there is provided an oblique nozzle 20 'passing between the transport rolls 5a and 5b and facing upward on the downstream side, and an oblique nozzle 20' passing between the transport rolls 5b and 5c and facing upward on the upstream side. Have been.

Similarly, below the transport roll 5d, there is disposed an oblique nozzle 20 'passing between the transport rolls 5d and 5e and directed upward on the upstream side.

These oblique nozzles 20 ', 20',...
The jet air of the nozzles 20, 20,... Jetting vertically upward can jet the jet air to a portion where the pressure distribution jetted to the glass plate surface is low, thereby compensating for the pressure shortage.

[0033]

According to the present invention, when bending an automotive window glass, the edge of the glass sheet intersecting with the transport roll for transporting the glass sheet, particularly, the upper side and the lower side of the rear window glass, are formed of the transport roll. A diagonal nozzle with a nozzle inclined obliquely upward is provided below, and the jet air jetted from the diagonal nozzle is passed between the transport rolls so as to be jetted obliquely. Pressure distribution of the blast air to the glass plate surface near the upper portion of the transport roll, which was not sufficiently removed or was interrupted by the transport roll, can be made uniform, and the optical distortion at the time of bending glass forming can be improved. Can now be prevented.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an embodiment of the present invention.

FIG. 2 is a plan view of a lift jet frame according to the embodiment of the present invention.

FIG. 3 is a side sectional view of another embodiment of the present invention.

FIG. 4 is a plan view of a lift jet frame according to another embodiment of the present invention.

FIG. 5 is a sectional side view illustrating a conventional bending method.

FIG. 6 is a plan view of a conventional lift jet frame.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass plate 4 Bending mold (mold) 5 Conveyance roll 10 Lift jet frame 20, 20 'Nozzle 21 Taper part 22 Column part

Claims (3)

[Claims] 1. A glass sheet bending method in which a glass sheet softened by heating is levitated by a high-temperature jet air flow and pressed against the lower surface of a bending die provided above to bend the glass sheet. The nozzles disposed below the edges of the two opposing sides in the direction are disposed immediately below the edges of the glass plate at substantially the center position between the transport rolls, and the injection direction is provided vertically upward. Is provided with an oblique nozzle directed obliquely upward, the jet air ejected by the oblique nozzle passes between the transport rolls, so as to compensate for the low portion of the air pressure ejected by the nozzle directed in the vertical direction, A method for forming a bent glass sheet, wherein the pressure distribution of jet air on the glass sheet surface is made uniform. 2. The upstream diagonal nozzle, which is the upstream diagonal nozzle and the downstream diagonal nozzle that are provided upstream or downstream of each nozzle provided vertically upward, has a downstream diagonally upper part and a downstream side. 2. The method of forming a bent glass sheet according to claim 1, wherein the oblique nozzle is jetted obliquely upward on the upstream side so as to pass between the transport rolls so that the jetting directions of both oblique nozzles intersect. 3. The method for forming a bent glass sheet according to claim 1, wherein the oblique nozzles are arranged at positions where the jet air jetted by the nozzles do not collide with each other.