JPH10152333A - Apparatus for flexural molding of glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus whose molding stage is equipped with a conveying means, lifting means, a mold and molding ring, enabling conducting a quick molding and conveying by pressing a glass plate so as to keep the glass temperature needed for quench reinforcing of the glass plate. SOLUTION: This apparatus is equipped with a heating stage ST1 wherein a glass plate 10 is carried into a heating furnace 1 and heated therein up to its molding temperature and conveyed by the first conveying means 11 inside the heating furnace 1. At the downstream side of the heating furnace 1, there is provided with a molding stage ST2 equipped with the second conveying means 12 for conveying the glass plate 10, a molding means 22 for sucking the glass plate 10 and lifting it upward from the second conveying means 12 and a molding ring 21 for pressing the glass plate 22 through the vertical motion of the molding means 22. The molding means 22 doubles as a lifting means for lifting the plate 10 from the conveying means 12. In such a situation that the pressed and bent glass plate is suckedly held by the molding means 22, the molding ring is retreated, the glass plate is conveyed to a stage ST3 by a cooling ring 31, thus obtaining the aimed glass plate subjected to flexural reinforcement.

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 bending a glass sheet for use in transportation equipment such as automobiles, ships, railways, aircrafts and the like, or for construction and other various uses.

[0002]

2. Description of the Related Art A glass plate heated to a temperature near a softening point in a heating furnace is conveyed by a plurality of rollers, and the glass plate is lifted by a forming ring provided below a curved roller in a forming stage, and is provided above the forming ring. There is known a method of bending a glass sheet by pressing it against a formed mold (for example, US Pat. No. 4,015,96).
No. 8).

[0003] In this case, the glass sheet pressed by the forming ring and the forming die is placed again on the conveying roller and conveyed to the next cooling stage, where it is rapidly cooled and strengthened.

[0004]

On the other hand, in order to quench and strengthen a glass sheet, it is necessary that the temperature of the glass sheet is maintained at a certain temperature near the forming temperature before quenching and strengthening. According to the method described in the above specification, the glass plate is pressed by a forming ring and a forming die, then lowered by a forming ring to a transfer roller, and then transferred to a cooling stage by the transfer roller. Therefore, the glass sheet transported from the heating furnace is quickly formed,
Need to be transported. However, no matter how quickly molding and conveying are performed, there is a limit to the speed, and it has been difficult to secure a temperature sufficient for rapid cooling.

Therefore, it is conceivable to increase the temperature of the glass sheet heated in the heating furnace to a desired temperature even if the temperature of the glass sheet is lost through molding and conveyance. However, if the temperature of the glass plate is too high, traces of the transfer by the transfer rollers are remarkably observed during the transfer, resulting in poor appearance of the completed glass plate and optical distortion.

An object of the present invention is to solve the above-mentioned disadvantages of the prior art, and to provide a new glass sheet bending apparatus which has not been known in the past.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a heating furnace for heating a glass sheet to a molding temperature and a first conveying means for conveying the glass sheet into the heating furnace. Bending of a glass sheet including: a heating stage having: a forming stage for bending and forming a glass sheet provided downstream of the heating furnace; and a cooling stage for rapidly cooling and strengthening the glass sheet provided downstream of the forming means. In the apparatus, the forming stage includes a second conveying unit that conveys the glass plate into the forming stage, a floating unit that raises the glass plate upward from the second conveying unit, and the glass plate is pressed. A molding die that bends a glass sheet by the method described above, and has a substantially peripheral shape of the glass sheet, and is located between the molding die and the second transportation means at a position outside the left and right sides of the transportation direction and above the second transportation means. The present invention provides a glass sheet bending apparatus, comprising: a two-part forming ring provided so as to be retractable; and pressing the glass sheet with the forming die and the forming ring. is there.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic sectional view showing an example of an entire configuration of a glass sheet bending strengthening step including a glass sheet bending apparatus according to the present invention. The glass plate 10 is conveyed into the heating furnace 1 in the heating stage ST1, and is heated to a molding temperature. At this time, the glass sheet 10 is transferred by the first transfer means 11 in the heating furnace 1.

A molding stage ST2 is provided downstream of the heating furnace. The forming stage ST2 includes a second transfer unit 12 for transferring the glass plate 10, a forming die 22 for sucking the glass plate 10 and moving upward from the second transferring unit 12, and a forming die 22. A forming ring 21 for supporting the glass sheet from below to press the glass sheet by vertical movement is provided.

The molding die 22 moves up and down between the second conveying means 12 and the upper side. Then, by this vertical movement, the glass plate is moved up and down while holding the glass plate by suction. That is, in this example, the flotation unit that raises the glass plate from the second transfer unit 12 is also used by the mold 22. And it has a lower convex surface which approximately matches the bent shape of the glass plate.

The forming ring 21 has a general shape of the periphery of a glass plate divided into two by a generatrix that divides the glass plate into two in the glass sheet conveyance direction (see FIG. 3). Then, the glass plate is disposed on the left and right sides in the transport direction and proceeds between the second transport means 12 and the forming die 22, and the glass plate is pressed together with the forming die 22 by the descending of the forming die 22.

[0012] The press-bent glass sheet is formed into a molding die 2.
The molding ring retracts to the left and right in the transport direction while being held by suction. Thereafter, the cooling ring 31 advances below the mold 22 from the downstream side in the transport direction, and receives the glass plate.
In this case, when the cooling ring 31 is positioned below the molding die 22, the suction of the molding die 22 is released,
The glass plate is transferred from the mold to the cooling ring.

The cooling ring that has received the glass plate transports the glass plate to the cooling stage ST3, and the glass plate is rapidly cooled and strengthened by cooling devices arranged above and below the glass plate. In this way, a glass sheet that has been strengthened by bending is obtained.

Next, the movement of the molding die and the molding ring in the molding stage ST2 will be described in more detail. FIG.
FIG. 2 is a schematic sectional view taken along line AA of FIG. 1. In this figure, illustration of a glass plate is omitted.

The molding die 22 moves up and down between an upper standby position of the second transfer means 12 and the second transfer means 12. On the other hand, the forming rings 21a and 21b move forward and backward between the upper part of the second transport means 12 and the outside of the second transport means 12, respectively.

When the glass sheet is conveyed below the molding die 22 by the second conveying means 12, the forming die 21 descends to the second conveying means 12 (to the conveying surface of the glass sheet), and Is held by suction. When the glass plate is sucked and held, the forming die 21 is moved from the conveying surface of the glass plate to the forming ring 21.
To a position that does not hinder the progress of

When the mold 22 rises, the molding ring 21
a, 21b are the second conveying means 12 and the molding die 22 from the left and right.
And progress between. Thereafter, the glass plate is press-bent formed by lowering the forming die 22 to the positions of the forming rings 21a and 21b.

When the glass sheet is bent in this manner, the forming die 22 holds the glass sheet by suction while holding the glass sheet.
1a and 21b retract to the left and right in the transport direction, respectively, and rise to a position where the cooling ring does not hinder progress from the downstream side in the transport direction. Thus, the suction of the mold 22 is released, the glass plate is delivered to the cooling ring, and the glass plate is transported to the cooling stage.

In the above example, the forming ring moves only in the horizontal direction, but may move in the vertical direction rising toward the forming die. That is, instead of the molding die adsorbing and holding the glass plate and then descending toward the molding ring, the molding ring rises and the glass plate can be pressed with the molding die and the molding ring. May be combined.

Further, particularly when the glass sheet is bent and formed into a shape in which the side portions (left and right sides) of the glass sheet are largely bent, such as a rear glass for an automobile, a forming ring by re-lowering of the above-mentioned forming die is used. Press can be omitted. That is, when the left and right sides of the glass plate are greatly bent,
The side of the glass plate into which the forming ring enters is pressed against the forming die so as to be positioned higher than the center. Therefore, the forming ring is curved so that the rear side is located at an upper position as compared with the front side on the entrance side. Therefore, it is possible to press the left and right sides of the glass plate against the forming die only by moving the forming ring forward, and it is possible to eliminate the re-down of the forming die.

The shape of the forming ring is substantially the same as the shape of the peripheral edge of the glass plate, but may be a shape in which only the portion corresponding to the above-mentioned left and right sides and the central portion of the peripheral edge is missing. Such a shape is preferable particularly when the configuration is such that the re-descent of the mold is omitted as described above.

In the above example, the glass plate is transported so that the long side is perpendicular to the transport direction. However, the orientation of the glass plate is appropriately determined according to the shape to be obtained.

The glass sheet in the present invention is heated to about 600 to 700 ° C. in a heating furnace. In this case, the glass plate may be transported in the heating furnace by rollers,
The glass plate may be conveyed while being levitated by heated air blown from below the heating furnace. Since a roller is preferable as the second conveying means because the next stage (forming stage) is outside the heating furnace, it is preferable that the roller is conveyed even in the heating furnace.

In the above example, since the forming die can adsorb the glass plate, the floating means of the present invention can be used also. In addition, by providing an air blowing device below the second transport means, the glass plate can be lifted upward. By keeping the temperature of the air at this time high, it is possible to prevent the temperature of the glass plate from lowering. Further, by floating the glass plate from below, it is not necessary to pick up the glass plate with the forming die, and thus, the molding time can be reduced.

FIG. 4 shows this example. The same components as those in FIG. 1 are denoted by the same reference numerals. The glass plate 10
The inside of the heating furnace 1 is conveyed by the first conveying means 11 and heated to the molding temperature. After exiting the heating furnace 1, the glass plate 1
Numeral 0 is floated up to the forming die 22 by air blown from the air blowing device 25 in the forming stage ST2. When the glass plate comes into contact with the molding die 22, the molding ring enters from the left and right sides of the second conveying means. Thus,
The glass plate is pressed against the forming die 22 by the forming ring 21 and bent.

Thereafter, the forming ring 21 is retracted to its original position, and the cooling ring 31 comes to meet the bent glass sheet. When the cooling ring 31 is positioned below the mold 22, the air from the air blowing device 25 is released, and the glass plate 10 is mounted on the cooling ring. Thus, the glass plate 10 is conveyed to the cooling stage ST3, where it is rapidly cooled and strengthened.

In this example, the vertical movement of the forming die is not required or requires only a minimum movement, so that the temperature of the glass plate can be prevented from lowering due to heat radiation, and the bending and transfer to the cooling stage can be realized quickly.

[0028]

According to the present invention, since the forming ring for pressing the glass sheet against the forming die in the forming stage is divided into two parts, the temperature of the glass sheet is prevented from lowering below the temperature required for rapid strengthening. In addition, the glass plate can be quickly bent and conveyed to the cooling stage.

For this reason, it is possible to prevent poor appearance after molding, which is caused by increasing the temperature at which the glass sheet is heated in anticipation of the temperature drop of the glass sheet, and to reduce the occurrence of optical distortion.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing an example of the entire configuration of a glass sheet bending strengthening step including a glass sheet bending apparatus according to the present invention.

FIG. 2 is a schematic sectional view taken along line AA of FIG. 1;

FIG. 3 is a schematic top view showing an example of a forming ring in the present invention.

FIG. 4 is a schematic sectional view showing another example of the overall configuration of the glass sheet bending strengthening step including the glass sheet bending apparatus according to the present invention.

[Explanation of symbols]

 1: heating furnace 10: glass plate 11: first conveying means 12: second conveying means 21: forming ring 22: forming die 31: cooling ring

Claims (2)

[Claims] 1. A heating stage having a heating furnace for heating a glass sheet to a molding temperature and a first conveying means for conveying the glass sheet into the heating furnace, and a glass sheet provided downstream of the heating furnace. In a glass sheet bending apparatus including a forming stage for bending and a cooling stage for rapidly cooling and strengthening a glass sheet provided downstream of the forming means, the forming stage includes a step of transferring the glass sheet into the forming stage. (2) conveying means, floating means for raising the glass plate upward from the second conveying means, a forming die for bending the glass sheet by pressing the glass sheet, and a schematic peripheral shape of the glass sheet. A left and right outer side in the carrying direction and above the second carrying means, and two divided forming rings provided so as to be able to advance and retreat between the molding die and the second carrying means, Before Glass sheet bending apparatus, characterized in that between the mold and the molded ring is to press the glass sheet. 2. The glass according to claim 1, wherein the formed ring divided into two parts has a substantially peripheral shape of a glass sheet divided into two parts by a generatrix that divides the glass sheet into two parts in the direction of transport of the glass sheet. Plate forming equipment.