JPH06340441A - Bending method of plate glass having covering layer and production of laminate glass using the same - Google Patents

Abstract

PURPOSE:To provide a bending method of a plate glass capable of burning a covering layer provided on the recessed, projecting or both faces of the plate glass. CONSTITUTION:The plate glass 8 having the covering layer is bent after the covering layer is burned by suspending in air and carrying the plate glass 8 in a heating furnace 1 by a carrying means jetting a heating air to the surface of the plate glass from the lower part of the plate glass 8 and the plate glass 8 is heated up to the temp. to soften the plate glass 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for bending a glass plate having a coating layer, and more particularly to a method for bending a glass plate for firing a coating layer made of enamel ink when the glass plate is heated and conveyed. It is about.

[0002]

2. Description of the Related Art Generally, a glass plate used for a window glass for a vehicle is bent into a desired shape so as to match a shape of a vehicle body or to obtain a streamline shape so as to reduce air resistance during traveling. It is molded. Such a glass plate is bent by self-weight bending in which a softened glass plate is placed in a ring-shaped bending die, bending using a vertical pressing furnace or a horizontal bending furnace, etc. Is heated to the softening point.

Further, especially on the windshield of a vehicle, 2
Laminated glass is used in which two bent glass plates are bonded together through an intermediate film made of synthetic resin. In order to obtain such laminated glass, two bent glass plates are used. Must have equal curvature.

In order to equalize the curvatures of the two glass plates as described above, conventionally, the two glass plates are heated and softened in a state of being superposed with a release agent, and placed on a ring-shaped bending die. It has been performed to obtain a laminated glass in which the curvatures of both are equalized by subjecting the laminated glass to self-weight bending or further bending by a press die.

[0005]

When a glass plate is attached to a vehicle, in order to improve the appearance of the attached portion,
A coating layer of black ceramic paint or the like is applied to the peripheral portion of the glass plate to hide the mounting portion from the outside of the vehicle. Further, in order to prevent the glass plate from being fogged, it is possible to print the silver paste in a line or apply a transparent conductive film such as a conductive metal or metal oxide on the surface of the glass plate and energize them. It is also common practice to use silver paste as a bus bar for energizing at that time.

These black ceramic paints and enamel inks such as silver pastes are used, for example, when two glass plates of the above-mentioned laminated glass are heat-softened in a state of being laminated with a release agent therebetween. Had a drawback that the glass plate was fused by the enamel ink.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. 61-31323, two glass plates of laminated glass are accurately positioned so that their curvatures become equal to each other.
It has been proposed to bend and form each sheet, but in this method, the enamel ink could not be applied to the lower surface of the glass plate that comes into contact with the rollers, because the rollers are conveyed in the heating furnace.

[0008] In particular, the first laminated glass is the inner side of the vehicle.
Enamel ink on both the outside surface (ie, convex surface) of the glass plate (hereinafter referred to as “inner plate”) and the inside surface (ie, concave surface) of the second glass plate (hereinafter referred to as “outer plate”) that is outside the vehicle. Since the unevenness of the bending die in the device is fixed from the beginning, either one of the outer plate and the inner plate described above should be conveyed with the enamel ink layer on the bottom surface. On the contrary, with the enamel ink layer on the upper surface, in order to apply both the outer plate and the inner plate, the uneven surface of the bending mold is provided on the concave surface of the glass plate or the convex surface of the enamel ink layer. It has to be changed depending on whether it is provided, and this change is extremely difficult because it requires a large-scale device change.

Like the recently proposed anti-fog laminated glass having a transparent conductive film, a black ceramic paint is applied to the concave surface of the outer plate, a transparent conductive film is provided almost in front of the convex surface of the inner plate, and a silver paste and black are applied to the periphery thereof. It was not suitable for bending a glass plate to obtain a laminated glass (see FIG. 3) provided with a ceramic paint.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and a method of bending a glass plate having a coating layer which has not been known hitherto and a bonding method using the same. A method for manufacturing glass is obtained.

[0011]

The present invention has been made in view of the above-mentioned problems, and after the glass plate having the coating layer is conveyed by the conveying means in the heating furnace and heated to a predetermined temperature, In the method for bending by a bending means, the conveying means blows heated air upward from the lower surface side of the glass sheet to levitate and convey the glass sheet, thereby bending the glass sheet having a coating layer. It provides a method.

Further, according to the present invention, by using the above bending method, two glass plates having a coating layer on one surface are separately bent into a predetermined shape, and then the intermediate film is placed so that the coating layers face each other. In the method for manufacturing a laminated glass in which the two glass plates are bonded to each other through the above-mentioned bending, in the bending process, heated air is jetted upward from the lower surface side of the glass plates in a heating furnace to float and convey the glass plates. The step of carrying the glass plate by the carrying means to heat the glass plate to a predetermined temperature, and then bending the glass plate by the bending means, wherein the first glass plate of the two glass plates is bent and coated. The conveyance surface of the first glass plate and the conveyance surface of the second glass plate are turned upside down so that the second glass plate is bent so that the layer is on the concave surface side and the coating layer is on the convex surface side. The surface of the There is provided a method for producing a laminated glass having a coating layer, characterized in that the flotation transport.

[0013]

According to the present invention, since the glass plate to be bent is floated and conveyed by jetting heated air, the coating layer such as the enamel ink applied on the surface of the glass plate does not contact the glass plate in a non-contact state. Since the enamel ink and the like can be conveyed and baked, the coating layer can be provided on both the concave surface and the convex surface of the glass plate.

Particularly, in the glass plate for laminated glass, the outer plate is provided with a coating layer on its concave surface and the inner plate is provided with a coating layer on its convex surface. Therefore, the glass plate can be bent without changing the bending means. Furthermore, a glass plate for anti-fog laminated glass having a transparent conductive film can be obtained.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram showing an example of a bending method according to the present invention. Inside the heating furnace 1, the glass plate 8 is floated and conveyed by a conveying means 3 called an air floating bed (hereinafter referred to as AFB) that ejects heated air from below the glass plate 8 toward the glass plate surface.

The AFB is made of a material having a high heat resistance, such as a silica block, and has a large number of holes for ejecting heated air. The heated air is a temperature at which the temperature of the glass plate softens 500 to 700 so that the glass plate can be softened sufficiently for bending.
C., preferably adjusted to 550 to 650.degree. Note that the AFB is inclined in the direction in which the glass plate is conveyed, so that the conveyance is smoothly performed.

A bending stage 2 is arranged downstream of the heating furnace 1, and a holding means 4 for positioning the glass plate above the glass plate being conveyed and sucking and holding the glass plate in a non-contact manner with the glass plate is provided. It has a lower mold 5 and an upper mold 6 as means. After that, the suction of the holding means 4 is stopped, and the glass plate is placed on the lower mold 5 arranged below the holding means. At this time, since the glass plate is accurately positioned by the holding means 4, the glass plate can be accurately placed on the lower mold 5.

The lower mold 5 is movable in the horizontal direction. The lower mold 5 moves to the position of the upper mold while placing the glass plate thereon, and the upper mold 6 is lowered toward the lower mold 5 so that the glass plate has a desired shape. It is bent into. The upper mold 6 may be provided with a suction function. In this case, the upper mold 6 holds the glass plate by suction, and a cooling (or slow cooling) ring 7 is provided below the upper mold 6. By moving, the glass plate can be easily received.

FIG. 2 is a sectional view showing a structural example of a glass plate having a coating layer, which is obtained by the method for bending a glass plate according to the present invention. (A) shows the concave side of the glass plate 11 coated with a black ceramic paint 12, further coated with a silver paste 13, bent and fired, and (b) shows the concave side of the glass plate 11 black. The ceramic coating 12 is obtained by coating the concave side of the glass plate 11 with the silver paste 13, bending and firing, and (c) shows the black ceramic coating 12 on the convex side of the glass plate 11 and further thereon. The silver paste 13 is coated, bent, and fired. in this way,
By the bending method as shown in FIG. 1, the glass plate having the coating layer of the enamel ink is bent regardless of the concave side or the convex side of the glass plate.

Of course, the present invention is not limited to the above drawings. For example, in FIG. 1, the lower die 5 has a convex surface on the upper side and the upper die 6 has a concave surface on the lower side in the bending means. However, conversely, the upper mold may be convex upward and the lower mold may be concave downward, and in the state where these bending means are set in advance, unevenness of the mold depending on the coating layer of the glass plate There is no need to change the face.

Further, in the present invention, when the glass plate is floated and conveyed, the lower surface of the glass plate becomes hotter than the upper surface because heated air is blown to the lower surface of the glass plate, and this temperature difference causes the glass plate to be heated. If there is a risk of deformation, a heater or heated air having a strength that does not hinder levitation transportation may be provided above the glass plate.

FIG. 3 is a partial schematic cross-sectional view showing a structural example of a laminated glass in which two glass plates obtained by using the bending method according to the present invention are adhered to each other through an intermediate film made of synthetic resin.

As shown in (a), the convex surface of the first glass plate (inner plate) 20 is coated with black ceramic paint on its peripheral edge, and the transparent conductive film 25 is formed on almost the entire surface thereof. Bus bars made of silver paste 23 are provided around the periphery of the transparent conductive film 25 to energize the transparent conductive film 25 to prevent the glass plate from being fogged. The concave surface of the second glass plate (outer plate) 21 is provided with black ceramic paint on the peripheral edge thereof. In this way, the laminated glass 30 is formed by bonding the convex surface of the inner plate 20 and the concave surface of the outer plate 21 with the intermediate film 24 interposed therebetween.

As shown in (b), the concave surface of the inner plate 20 is provided with black ceramic paint on the peripheral edge thereof. On the concave surface of the outer plate 21, a black ceramic paint is applied to the peripheral portion of the concave surface, and a transparent conductive film 25 is provided substantially on the front surface thereof. Bus bars made of anti-fog silver paste 23 are provided respectively. In this way, the laminated glass 30 is formed by bonding the convex surface of the inner plate 20 and the concave surface of the outer plate 21 with the intermediate film 24 interposed therebetween.

In addition to the above two examples, various coating layer patterns are conceivable. In any case, according to the bending method of the present invention, fusion with other coating layers such as enamel ink is possible. It is possible to bend a bent glass plate for laminated glass without wearing, poor adhesion or poor processing.

Of the above two anti-fog laminated glasses, the structure shown in (a) has a transparent conductive film provided on the inner plate, so that fogging of the inner plate can be efficiently removed. It is preferable in that the transparent conductive film does not crack even if it is broken, and abnormal heat generation and ignition due to the crack can be prevented.

[0027]

According to the present invention, since a glass plate to be bent is floated and conveyed by jetting heated air, the glass layer is covered with a coating layer of enamel ink or the like in a non-contact state. Since the plate can be conveyed and the enamel ink or the like can be baked, it is possible to obtain a method for bending a glass plate, which can provide a coating layer on both the concave surface and the convex surface of the glass plate and further on both surfaces. it can.

In particular, even when a coating layer is provided on each of the concave surface of the outer plate and the convex surface of the inner plate, such as a glass plate for laminated glass, the glass plate is bent without changing the bending means. Further, it is possible to obtain a glass plate for anti-fog laminated glass having a transparent conductive film.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing an example of a method for bending a glass plate according to the present invention.

FIG. 2 is a sectional view showing a constitutional example of a glass plate having a coating layer in the present invention.

FIG. 3 is a partial schematic cross-sectional view showing a constitutional example of a laminated glass obtained by using a bending method according to the present invention.

[Explanation of symbols]

 1: Heating furnace 2: Bending stage 3: Conveying means 4: Holding means 5: Lower mold 6: Upper mold 7: Ring 8, 11: Glass plate 12, 22: Black ceramic paint 13, 23: Silver paste 20: First Glass plate 21: second glass plate 24: intermediate film 25: transparent conductive film 30: laminated glass

Claims (6)

[Claims] 1. A method in which a glass plate having a coating layer is conveyed by a conveying means in a heating furnace to be heated to a predetermined temperature and then bent by a bending means, wherein the conveying means is upward from a lower surface side of the glass sheet. A method for bending a glass plate having a coating layer, characterized in that heated glass is ejected toward the glass plate to float and convey the glass plate. 2. A glass plate is coated with a coating layer made of enamel ink on at least one side surface, and the enamel ink is baked to bend the glass plate when it is floated and conveyed in a heating furnace. A method for bending a glass plate having a coating layer according to claim 1. 3. The glass plate carried by the carrying means is positioned and held by a holding means which has a positioning means and sucks upward to suck and hold the glass plate, and then places it on the bending means. Claim 1 characterized by the above.
Alternatively, a method of bending a glass plate having a coating layer of 2. 4. The bending means includes at least a lower die movable in a substantially horizontal direction and an upper die movable in a substantially vertical direction and having a suction function. The glass plate is placed on the lower mold, the lower mold is moved to a position where the upper mold is provided, and the upper mold is lowered to bend the glass plate. Alternatively, a method of bending a glass plate having a coating layer of 2. 5. Two glass plates each having a coating layer on one surface are separately bent into a predetermined shape, and then the two glass plates are bonded via an intermediate film so that the coating layers face each other. In the method for manufacturing a laminated glass, the bending is carried out by transporting the glass sheet by a transporting means for jetting heated air upward from the lower surface side of the glass sheet in the heating furnace to levitate the glass sheet. After heating to a predetermined temperature, including a step of bending by bending means,
Of the two glass plates, the first glass plate is bent so that the coating layer is on the concave side, and the second glass plate is bent so that the coating layer is on the convex side. A method for producing a laminated glass having a coating layer, characterized in that the first glass plate and the second glass plate are arranged so that they are upside down with respect to each other. 6. The coating layer of the two glass plates is printed with enamel ink, and the enamel ink is baked when being floated and conveyed in a heating furnace. The manufacturing method of the laminated glass which has a coating layer of 5.