JP3734278B2 - Glass plate bending equipment - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a bending apparatus for glass plates such as window glass for vehicles.
[0002]
[Prior art]
In general, a glass plate used for a window glass for a vehicle is bent and formed into a desired shape so as to match the shape of the vehicle body or to obtain a streamline so that air resistance during traveling can be reduced. Such glass plate bending methods include a self-weight bending method in which a glass plate is placed on a ring-shaped bending die, and a bending method using a vertical press furnace or a horizontal bending furnace.
[0003]
Examples of the bending method using a horizontal bending furnace include the following method disclosed in US Pat. No. 5,004,491. That is, the glass plate heated in the heating furnace by the conveying means comprising rollers is carried into the horizontal bending furnace, and the glass plate is conveyed to the vicinity of the downstream end of the horizontal bending furnace. In the vicinity of the end, a glass plate suction holding device comprising a block (hereinafter referred to as ASB) provided with a small hole for ejecting air and a small hole for sucking is disposed above the conveying means. Air is sucked into the block from a small hole provided on the entire holding surface of the glass plate suction holding device, and the glass plate is held by the glass plate suction holding device by this suction force.
[0004]
The glass plate held by the glass plate suction holding device is placed on a lower mold for bending forming arranged below the glass plate suction holding device. At this time, the glass plate is once prepared above the lower mold for bending by a glass plate suction holding device. As a result, the glass plate is not tilted or deformed on the mold when placed on the mold, and the glass plate is press-bended by the upper mold for bending after being correctly placed on the lower mold for bending. Molded.
[0005]
When a bent glass plate is attached to a vehicle, the glass plate needs to be accurately formed into a shape corresponding to the shape of the vehicle body. In particular, as a windshield of a vehicle, a laminated glass obtained by laminating and bonding a laminated intermediate film such as a polyvinyl butyral film between two glass plates is widely used. When manufacturing such a laminated glass, the following inconvenience arises if the curvatures of the mating surfaces of the two glass plates do not coincide with each other in whole or in part. Damage to the glass plate in the crimping process for producing laminated glass. Unfavorable foaming phenomenon on the mating surfaces and peeling of the mating surfaces after long-term use. In order to prevent these inconveniences, when manufacturing a laminated glass having a curved surface, it is necessary to make the curvatures of the mating surfaces of the two glass plates coincide with each other, and it must be formed more accurately than a single plate side glass or the like. .
[0006]
The shape and curvature of the glass plate depend on the shape of the bending mold. In order to perform the precise bending as described above, it is necessary that the glass plate is always placed at a desired position when it is placed on the lower mold for bending. Therefore, the glass plate is properly positioned and held when sucked and held by the glass plate suction holding device so that the glass plate can be placed at an accurate position on the lower mold for bending. Placed on the mold.
[0007]
Specifically, positioning means is provided below the ASB so as to be parallel to the holding surface. This positioning means has a metal arm portion inserted so as to be able to move forward and backward from the left and right outside the furnace, and a glass plate receiving portion made of a metal disc provided at the tip thereof. It is positioned at a desired position. The glass plate positioned and held at the desired position by the positioning means is then placed at the desired position of the lower mold for bending.
[0008]
[Problems to be solved by the invention]
In the bending apparatus as described above, the glass plate is sucked by the suction holding device and is held in a non-contact manner at a position of about several mm below the suction holding device, and in some cases, 1 mm or less. Therefore, it is necessary to finely adjust the distance of the arm portion from the suction holding device so that the glass plate receiving portion can correctly receive the end surface of the glass plate.
[0009]
However, the positioning means of the bending apparatus is inserted so as to be able to advance and retreat from the left and right outside the furnace. The arm portion of the positioning means 4 made of metal is warped due to a temperature change caused by advancing and retreating from cold to hot and a temperature change caused by repeating or stopping the molding cycle. Therefore, a gap between the glass plate 2 held by the suction holding device 3 and the suction holding device 3 and a gap between the glass plate receiving portion of the positioning means 4 and the suction holding device 3 are different, and the glass plate is applied to the mold. Precise positioning could not be performed (see FIG. 3).
[0010]
In addition, when the arm part is warped in this way, the height and position of the arm part must be readjusted in order to perform precise positioning of the glass plate to the mold, and the bending process is interrupted. Was forced to spend extra time and effort.
[0011]
An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and to provide a glass sheet bending apparatus that has not been conventionally known.
[0012]
[Means for Solving the Problems]
The present invention has been made in view of the above-described problems, and includes a conveying unit that conveys a glass plate in a heating furnace, and a bending mold that is arranged downstream of the conveying unit and forms a heat-softened glass plate. And a glass plate suction holding device that is disposed on the upper downstream side of the conveying means and that is placed on the bending mold after sucking and holding the glass plate, and a glass plate at a desired position of the glass plate suction holding device. A glass plate bending apparatus comprising at least positioning means for positioning, wherein the positioning means is movable under and parallel to the glass plate holding surface of the glass plate suction holding device so as to be movable back and forth substantially below the glass plate suction holding device. disposed, and said is only holding surface and cantilevered in a position not facing the glass plate suction holding device, at least an arm portion of the movably inserted long from the left and right outside the furnace, Serial arm portion, there is provided an apparatus for bending a glass sheet, characterized in that it consists of silicon nitride ceramics or carbide ceramics.
[0013]
[Action]
According to the present invention, the arm portion of the positioning means disposed so as to be able to advance and retract substantially parallel to the glass plate holding surface of the glass plate suction holding device is made of silicon nitride ceramics or carbonized carbon which is heat resistant and has a low coefficient of thermal expansion. Made of silicon ceramics. Therefore, the warp of the arm portion can be reduced even under the temperature change accompanying the advance and retreat from cold to hot during operation of the arm portion. Moreover, in the case of such a material, even if it is an arm part which becomes long, the moldability is easy and its dimensional accuracy is also excellent.
[0014]
Further, according to the present invention, since the warp of the arm portion of the positioning means is small, the glass plate is accurately positioned without interrupting the bending forming process and adjusting the arm portion, thereby bending the glass plate. Is done.
[0015]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an example of a glass sheet bending apparatus of the present invention. In the heating furnace 11, there is provided conveying means 1 called an air floating bed (hereinafter referred to as AFB) that floats and conveys the glass plate 2 by blowing hot air from below the glass plate 2. A glass plate suction / holding device 3 made of ASB is provided downstream of the conveying means 1 to hold the glass plate 2 by suction and place the glass plate 2 horizontally on the lower bending mold 8. The glass plate suction and holding device 3 reciprocates between AB of the conveying means 1 and the lower bending mold 8.
[0016]
Positioning means having an arm portion made of silicon nitride ceramic for positioning the glass plate 2 conveyed downstream by the conveying means 1 at a desired position of the glass plate suction holding apparatus 3 below the glass plate suction holding apparatus 3. 4 is arranged.
[0017]
The bending forming means for forming the heat-softened glass plate 2 is composed of the above-described lower bending mold 8 and the upper bending mold 7, and the lower bending mold 8 receives the glass sheet 2 after receiving it. The glass plate 2 is press-bended by moving to below the upper mold 7 for bending. In addition, the slow cooling means 9 may be arranged downstream of the bending forming means.
[0018]
With such a bending apparatus, the glass plate is formed as follows. The glass plate 2 is heated to a temperature sufficient for bending in the heating furnace 11, for example, about 550 to 650 ° C., conveyed by the conveying means 1, and then sucked by the glass plate suction holding device 3 provided downstream of the conveying means 1. Hold.
[0019]
At this time, the glass plate 2 is positioned by the positioning means 4 disposed below the glass plate suction and holding device 3 so that the glass plate 2 can be placed at a desired position on the lower mold 8 for bending.
[0020]
Furthermore, after the glass plate 2 is positioned and sucked and held at a desired position of the glass plate suction and holding device 3 by the positioning means 4, the glass plate 2 is placed on the lower mold 8 for bending. While the glass plate 2 is placed, the lower bending mold 8 is moved below the upper bending mold 7 and the glass sheet 2 is press-molded by the lower bending mold 8 and the upper bending mold 7. Then, it is conveyed to the slow cooling means 9.
[0021]
FIG. 2 is a side view (a) and a plan view (b) showing an example of the positioning means in the present invention. The arm portion 41 made of silicon nitride ceramics of the positioning means 4 of the glass plate 2 is arranged below the suction holding device 3 that sucks and holds the glass plate 2 and is parallel to the holding surface 31 of the suction holding device 3. It can be moved to a desired position so as to be movable forward and backward in the direction.
[0022]
A glass plate receiving portion 42 made of silicon nitride ceramics for receiving the end surface of the glass plate 2 is connected to the tip of the arm portion 41. The glass plate receiving portion 42 is moved in a direction parallel to the holding surface 31 by the arm portion 41. In this way, the glass plate receiving portion 42 is moved to a desired position, the end surface of the glass plate 2 is received by the glass plate receiving portion 42, and the glass plate 2 is positioned.
[0023]
The present invention is not limited to only the embodiments based on the drawings. For example, the shapes of the upper mold and the lower mold are appropriately determined so as to match the shape of the glass plate to be obtained, and the lower mold is convex and the upper mold is concave as shown in the above drawing. Or vice versa, and the cross section may be substantially S-shaped so that the shape of the formed glass plate is a double curved surface.
[0024]
The method of bending is not limited to press bending with the upper mold and the lower mold as in the above-described embodiment, and even when bending by the weight of the softened glass plate, the bending mold is only the lower mold. A ring-shaped self-weight bending mold may be used.
[0025]
Also about a heating furnace and a conveyance means, it is not limited to the thing of illustration. In addition to the AFB used in the above-described embodiments, the conveying means includes those conveyed by rollers and other means, and those capable of smoothly conveying a heat-softened glass plate are appropriately selected and used.
[0026]
The arm part of the positioning means and the glass plate receiving part may be mounted separately by the connecting part, or the tip of the arm part itself may be the glass plate receiving part. Although there is no restriction | limiting in particular also in the shape of a glass plate receiving part, In view of the point which can receive a glass plate softly, it is preferable that a glass plate receiving part is substantially circular shape.
[0027]
The glass plate receiving portion of the positioning means may be the same material as the arm portion or a different material such as metal. In view of the fact that the positioning of the glass plate receiving part is prevented by preventing warp deformation and the like of the glass plate receiving part, the material of the glass plate receiving part is a low heat such as silicon nitride ceramics or silicon carbide ceramics used in the above embodiment. Those having an expansion coefficient are preferred.
[0028]
【The invention's effect】
According to the present invention, the arm portion of the positioning means that is arranged to be able to advance and retreat substantially in parallel with the glass plate holding surface of the glass plate suction holding device is made of silicon nitride ceramics or silicon carbide ceramics that is a material having a low coefficient of thermal expansion. Therefore, it is possible to obtain a glass plate bending apparatus that can reduce the warp of the arm portion even under a temperature change accompanying the advance and retreat from cold to hot, and can accurately position the glass plate.
[0029]
Further, according to the present invention, since the warping of the arm portion of the positioning means is small, the frequency of adjusting the arm portion by interrupting the bending forming process is reduced, and the bending step is interrupted to adjust the arm portion. The labor and time can be reduced, and an efficient bending of a glass plate becomes possible.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing an example of a glass sheet bending apparatus of the present invention. FIG. 2 is a side view (a) and a plan view (b) showing an example of positioning means in the present invention.
FIG. 3 is a sectional view of a main part showing a conventional positioning means.
1: Conveying means 2: Glass plate 3: Glass plate suction holding device 4: Positioning means 7: Upper mold for bending molding 8: Lower mold for bending molding 9: Slow cooling means 11: Heating furnace 31: Holding surface 41: Arm portion

Claims (2)

Conveying means for conveying the glass plate in the heating furnace, a bending mold for forming the heated and softened glass plate arranged downstream of the conveying means, and a glass plate arranged above the downstream of the conveying means A glass plate bending and forming apparatus comprising at least a glass plate suction and holding device that holds the glass plate on a bending mold and positioning means for positioning the glass plate at a desired position of the glass plate suction and holding device Because
The positioning means is arranged below the glass plate suction holding device so as to be able to advance and retreat substantially in parallel with the glass plate holding surface of the glass plate suction holding device, and at a position not facing the holding surface of the glass plate suction holding device. It has at least a long arm part that is only supported and inserted so that it can move forward and backward from the left and right outside the heating furnace ,
The glass plate bending apparatus, wherein the arm portion is made of silicon nitride ceramics or silicon carbide ceramics.   2. The glass plate bending apparatus according to claim 1, wherein the positioning means includes the arm portion and a glass plate receiving portion that is provided at a tip of the arm portion and receives an end surface of the glass plate.

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