JPH10291828A - Glass sheet forming equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the temps. in the respective zones of a heating furnace at prescribed temps. by constituting a door which is disposed between a heating zone and a slow cooling zone and opens and closes as forming molds are put into and out of the furnace in such a manner that the door is housed into a box-shaped enclosure when the door is open. SOLUTION: A glass sheet is properly slowly cooled in order to control the stress generated in the glass sheet. The temp. in the slow cooling zone 105 is required to be kept at the prescribed temp. and, therefore, the door 15' is disposed between this zone end the heating zone 104 and is so constituted that the door 15' shuns off between both zones and opens at the time of transferring the forming molds. Namely, the upper side of a wall 84 is provided with an opening 82 for advancing and retreating the door to communicate the inner side of the heating furnace 11 and the thin box-shaped enclosure 80 side in such a manner that the door 15' is movable vertically. The opening end face of the opening 82 for advancing and retreating the door is pressed via a thermal insulating material to the outer flank of the furnace wall 84 in such a manner that the opening is included on the inner peripheral side. The door 15' is housed into the box when the door 15' opens.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for bending a glass sheet.

[0002]

2. Description of the Related Art In forming a glass plate from a flat plate to a curved surface, bending is performed by heating the glass plate to a temperature equal to or higher than the softening point temperature (normally about 600 to 700 ° C.). There are several techniques for this forming process. As an example, a method in which a glass plate placed on a ring-shaped mold in a heating furnace is conveyed, and the glass sheet is bent and shaped so as to follow the shape of the mold by using the sagging due to its own weight (hereinafter, referred to as a self-weight bending method).
There is.

[0003] The inside of the heating furnace must be maintained at a desired temperature in order to bring the temperature of the glass sheet to a predetermined temperature. This is because the bent shape of the glass plate changes according to the forming temperature. For that purpose, it is required that the inside of the heating furnace be a closed space so that the inside of the heating furnace is maintained at a desired temperature.

Japanese Patent Publication No. 6-17242 discloses a heating furnace according to the above-described gravity bending method. In the glass sheet forming apparatus disclosed in the above publication, the glass sheet is placed on a carriage having a forming die, and the carriage moves in a heating furnace to heat the glass sheet. Then, the glass sheet placed on the molding die on the cart is heated to the softening point temperature or higher in the upper stage (outward path) of the heating furnace, bent and formed, transferred to the lower level, and advanced to the lower level (return path). It is cooled slowly. The glass sheet after the slow cooling is collected in the lower glass sheet transfer zone, and the glass sheet before forming is placed on the empty forming die.

[0005] Each carriage is provided with a partition wall on the traveling direction side. In the above-mentioned transfer zone, the entrance and exit of the heating furnace are closed by a partition wall so that the temperature in the heating furnace does not change during the transfer operation of the glass plate, and the entire heating furnace is a closed space. Thus, the temperature in the heating furnace is stabilized.

[0006]

However, when a truck having a partition wall is conveyed into a heating furnace as described in the above publication, the volume of the truck becomes large. This requires not only an increase in the amount of the partition wall but also the necessity of mounting and reinforcing to withstand the transportation of the partition wall, so that the overall volume including the reinforcing component becomes extremely large. For this reason, since the heat in the heating furnace is taken away by the bogie, the thermal efficiency is reduced and a large amount of energy is consumed.

On the other hand, in the case of mass production such as a bent glass sheet for an automobile, the flow of the glass sheet itself is preferably one-way movement, not reciprocating movement. Therefore, a device in which a glass plate reciprocates as in the above-mentioned publication is not suitable for mass production of bent glass plates.

Therefore, it is conceivable to make the entrance and exit of the apparatus of the above-mentioned publication separate. Thereby, the movement of the glass sheet can be made in one direction, and the apparatus can be made suitable for mass production. However, in this case, in order to make the inside of the heating furnace during the transfer operation of the glass plate a closed space, it is necessary to provide a partition wall of the truck before and after the truck. In this,
In addition to this, the thermal efficiency is poor, and the number of partition walls further increases, which further deteriorates the thermal efficiency. Therefore, it is practically difficult to make the apparatus suitable for mass production such that the glass plate is moved in only one direction.

An object of the present invention is to eliminate the above-mentioned disadvantages of the prior art, and to provide a new apparatus for forming a glass sheet, which has not been known before.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and comprises a plurality of divided heating zones for heating a glass sheet to a forming temperature, and a heating zone arranged downstream of the heating furnace. And a tunnel-shaped heating furnace having a slow cooling zone for gradually cooling the glass sheet, and the glass sheet was placed from the upstream of the heating zone to the downstream of the slow cooling zone through the plurality of heating zones and the slow cooling zone. In a glass sheet forming apparatus provided with at least a conveying means for conveying a forming die, a furnace wall of a heating furnace corresponding to between the heating zone and the annealing zone is opened and closed as the forming die enters and exits. A door advance / retreat opening is provided so that the door 1 can advance and retreat between the inside of the heating furnace and the outside of the heating furnace, and a door advance / retreat opening is provided on a furnace wall outer surface located on an outer periphery of the door advance / retreat opening. A box-shaped enclosure with an opening on the side, Is provided so as to abut on the inner periphery of the opening to include a door advancing / retreating opening and protrude outward from the heating furnace, and the door is housed in the box-shaped enclosure in its open state. Provided is a glass sheet forming apparatus characterized by being configured as described above.

In this case, the conveying means intermittently conveys the mold to each of the heating zones and the slow cooling zone, and keeps the mold in each heating zone except for the heating zone adjacent to the slow cooling zone. The time T ₀ is constant, and the residence time T ₁ of the mold in the heating zone adjacent to the annealing zone is variable to T ₀ or less. Preferably, the first door is opened.

Further, the heating furnace is provided at an upper stage of a return zone for returning a forming die after the formed glass sheet is recovered to an entrance of the heating furnace, and is provided at an entrance of the heating furnace and an exit of the heating furnace. A first and a second elevating zone having a lifter for elevating and lowering the mold between the return zone and the heating furnace are provided adjacent to each other, and the transfer means is provided with the first and second elevating zones from the heating furnace.
Extending to the second elevating zone, the first elevating and lowering is performed in accordance with the transfer of the die from the first elevating zone to the heating zone and the transfer of the die from the slow cooling zone to the second elevating zone. Preferably, a second door arranged between the zone and the entrance of the heating furnace and a third door arranged between the exit of the heating furnace and the second elevating zone are opened.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is an overall schematic sectional view showing an example of a glass sheet forming apparatus of the present invention. The heating furnace 11 includes four divided heating zones 101 to 104 and a slow cooling zone 105. A plurality of heaters are provided on the inner wall and formed in a tunnel shape. The glass plate to be formed is heated zone 1
01 side entrance 91 to slow cooling zone 105 side exit 95
The sheet is placed on the mold 30 and transported by the transport means, and is bent and shaped so as to follow the shape of the mold 30. In this case, the molding die 30 is placed on a conveying means composed of a conveyor belt, a drive chain or the like, and runs in the heating furnace 11 intermittently for each heating zone and slow cooling zone by driving of the conveying means.

The heating furnace 11 is provided at the upper stage of the mold return zone 12 in which the molding die 30 on which the glass plate has been formed is returned to the heating zone 101 side, and has a two-stage structure as a whole apparatus. The heating furnace 11 and the mold return zone 12 are located between the heating furnace 11 and the mold return zone 12.
Zone 1 having lifters 13 and 13 ′ for moving
4, 14 '. Lifting zone 14
Is located adjacent to the entrance of the heating zone 101,
4 ′ is adjacent to the outlet of the annealing zone 105.

Thus, the mold 3 in the elevating zone 14
The molding die 30 can be transferred to the upper stage by placing the glass plate on 0 and raising the lifter 13. Then, the molding die 30 in which the glass plate has been formed in the elevating zone 14 'is transferred to the lower stage by lowering the lifter 13', the glass plate is collected from the molding die 30, and the glass plate is transferred to the next step. Meanwhile, the mold can be returned.

The heating furnace 11 has doors 15, 1 at predetermined positions.
5 ′, 15 ″ are provided.
Between the heating zone 101 which is the entrance 91 of the heating zone 101 (the front surface of the heating zone 101) and the elevating zone 13;
Between the cooling zone 105 and the outlet 95 of the heating furnace 11
A second, first, and third doors 15, 15 ', 15 "for maintaining the inside of the furnace in a closed space between the slow cooling zone 105, which is the rear surface of the slow cooling zone 105, and the elevating zone 13'. These doors 15, 15 ', 15 "are
It is configured to open only when 0 passes and close at other times.

A second furnace provided at the entrance 91 of the heating furnace 11
Door 15 is opened in accordance with the advance of the mold 30 from the elevating zone 14. Mold 30 is heated zone 1 of heating furnace 11
After moving into 01, the door 15 closes. This door 15
In order to prevent the heat inside the heating furnace 11 from escaping outside the furnace, the mold 30
Open only when it moves.

Thereafter, when the mold 30 moves to the annealing zone 105, the first door 15 'provided between the annealing zone 105 and the heating zone 104 in front thereof is also moved by the molding door 30'. Open as the process progresses. The temperature in the slow cooling zone is lower than the temperature in the adjacent heating zone 104. Therefore, a first door 15 'is provided to maintain the temperature in each of adjacent zones having different temperatures.

A third door 15 "is provided between the outlet 95 of the heating furnace 11 and the elevating zone 14 '.
It is also configured to keep the temperature inside the heating furnace. The door 15 ″ is also opened only when the mold 30 is carried out from the slow cooling zone 105 to the elevating zone 14 ′.

The doors 15, 15 ', 15 "open and close vertically, and are provided with an enclosure 80 above the heating furnace 11 so as to include a guide for opening upward. It is also possible to prevent the temperature from being taken out of the furnace, and to provide an enclosure on the side surface of the heating furnace 11 so that some or all of the doors can be opened and closed right and left. The opening and closing direction of each door can be appropriately determined according to the location. However, in view of the fact that the opening and closing mechanism including the stabilization of the opening and closing mechanism can be simplified, it is preferable to open and close the door vertically.

FIG. 2 shows a main part including a door of the glass sheet forming apparatus of the present invention. FIG. 2A is a schematic front cross-sectional view of the main part, and FIG. 2B is a schematic cross-sectional view of the main part. The opening and closing mechanism of each door may be an appropriate mechanism, but in this example, the opening and closing mechanisms of each door are all set to be the same. FIG. 2 shows a mechanism of the first door 15 ′ which is typically provided between the heating zone 104 and the slow cooling zone 105.

At the boundary between the heating zone 104 and the slow cooling zone 105, a first door 15 'is provided. Above the furnace wall 84 at the boundary between the heating zone 104 and the slow cooling zone 105, a door advance / retreat opening 82 is provided.
The inside of the heating furnace and the side of the enclosure 80 communicate with each other so that 5 ′ can move up and down. The enclosure 80 has a thin box shape having an opening that opens toward the door advance / retreat opening 82 side.
Then, the door advance / retreat opening 82 is included on the inner peripheral side,
The opening end surface of the opening is in contact with the outer surface of the furnace wall 84 via a heat insulating material, and the door 15 'is accommodated in this box when the door 15' is opened.

The enclosure 80 is in contact with the outer surface of the furnace wall 84 via a heat insulating material at a bracket portion (not shown), and is bolted to the furnace wall 84. The heat insulating material interposed between the enclosure 80 and the furnace wall 84 thermally seals the abutting portion between the two. The enclosure 80 is formed from a board material including a heat insulating material.

The door 15 'is connected at its upper part to a driving means 81 via a connecting member 83 such as a chain or a wire, and moves up and down by the driving of the driving means 81.
The space between the heating zone 104 and the slow cooling zone 105 is shielded and opened. As the driving means 81, an appropriate one can be used. In this embodiment, the door 15 'is opened and closed by rotating the sprocket by using an air cylinder as a driving source to wind up and open the connecting means.

Providing the door as in the present invention is effective for securing a stable and predetermined temperature in the heating furnace. In particular, the door 15 'provided between the heating zone 104 and the slow cooling zone 105 is particularly effective for maintaining a predetermined temperature. That is, in order to control the stress generated in the glass plate, the glass plate is gradually cooled. For that purpose, it is necessary to maintain the temperature in the slow cooling zone at a predetermined temperature. On the other hand, when the heating zone and the slow cooling zone are adjacent to each other, if the heat in the heating zone is transferred to the slow cooling zone, the temperature of the slow cooling zone cannot be maintained at a predetermined temperature.

Therefore, it is not possible to provide a door between the heating zone and the gradual cooling zone to shield between them, as in the above example, and to open the door when necessary (when transferring the mold). It is valid. Further, by interlocking the driving of the conveying means of the mold and the driving of the opening and closing mechanism of the door so that the door is opened and closed in accordance with the timing at which the mold is transferred from the heating zone to the slow cooling zone, the slow cooling is performed. This is particularly effective for maintaining a predetermined temperature in the zone. This interlocking greatly contributes to maintaining a predetermined temperature in the slow cooling zone when the residence time in the heating zone 104 is appropriately changed for each type of glass sheet to be formed as described below.

That is, in this example, of the heating zones,
Heating zone 1 from entrance 91 of heating furnace 11 to the third
Each of the molds 30 stays for a certain time in 01 to 103. On the other hand, the heating zone 10 just before the slow cooling zone 105
The stay time of the mold 30 at 4 is variable. Thereby, the heating time is changed according to the bent shape of the glass sheet to be obtained. With such a configuration, the residence time in the heating zone 104 is long when the glass plate is bent large (the radius of curvature is small), and the heating zone 104 is used when the glass plate is bent small (the radius of curvature is large).
It is preferable to shorten the staying time in the above, since a glass sheet having a desired bent shape can be obtained for each model. And
In order to realize such a preferable embodiment, it is preferable to convey the mold from the upstream to the downstream of the heating furnace intermittently for each zone as in this example.

The adjustment of the stay time will be described. In the heating zone 101 to 103, the mold 30 are each time T ₀ to stay. On the other hand, the residence time T ₁ of the mold 30 in the heating zone 104 is the maximum T ₀ , and T ₁ is reduced according to the bent shape of the glass sheet to be obtained.
By the way, when the mold is conveyed from the heating zone 104 to the annealing zone 105 at T ₁ <T ₀ , there is a scene where the mold 30 is not in the heating zone 104. T ₁ after,
Further, when (T ₀ −T ₁ ) = T _{2 has} elapsed, the mold 30 is transported from the heating zone 103 to the heating zone 104. In accordance with this, the conveying means is driven, so that the conveying means in the heating zone 104 where the mold 30 is not placed is also driven.
The conveying means in 05 is also driven. In this state, the glass sheet on the mold previously conveyed into the annealing zone 105 has an annealing time of only T _{2 and} cannot be sufficiently cooled.

Therefore, as shown in FIG.
It is preferable that the lifting / lowering means 16 be provided in the inside 5 so that the driving of the transport means 70 is not transmitted to the molding die 30 temporarily.
That is, when bending a glass plate of a certain type, the mold in the heating zone 101 to 103, which T ₀ stay in each zone. At this time, the heating zone 104
The mold at ₁ stays in this zone for T1. Time T
After _one elapse, the mold in the heating zone 104 is moved to the annealing zone 1
05. On the other hand, if T ₁ <T ₀ , the molds in the heating zones 101 to 103 still stay in the respective zones.

After the elapse of the time T ₂ , the heating zone 1
The molds in 01 to 103 are each conveyed to the adjacent heating zone. At this point, the glass plate annealing zone 105 T ₂ only not given annealing time. At this time, the molding die 30 is raised by the elevating means 16 from the conveying means 70 so that the glass plate in the annealing zone 105 is not conveyed to the outside of the heating furnace 11 by the driving of the conveying means. In this way, the conveying means 70 and the molding die 30 can be separated from each other so that the driving of the conveying means 70 is not applied to the molding die 30. Thereafter, when the driving of the transporting means is stopped, the mold 30 separated from the transporting means 70 is placed on the transporting means 70, and the slow cooling zone 105
When the molding die 30 is transported from the heating furnace 11 to the heating furnace 11, the drive of the transport means 70 is transmitted to the molding die 30.

After the elapse of the time T ₁ , the heating zone 10
When the next molding die 30 in 4 is conveyed to the annealing zone 105, the molding die 30 in the annealing zone is conveyed to the outside of the heating furnace 11 (elevation zone) by the conveying means 70. After that, in the elevating zone, the forming die is transferred below the heating furnace by the lifter, and the formed glass plate is
The mold is transported through the mold return zone to the elevating zone before the heating zone 101. The first and third doors in this example are opened and closed in accordance with the timing of the transfer of the above-mentioned mold, whereby the temperatures of the heating zone 104 and the slow cooling zone 105 can be maintained at desired temperatures. it can.

As described above, in FIG. 2, the first door 1 typically located between the heating zone 104 and the slow cooling zone 105 is shown in FIG.
The 5 ′ mechanism is shown. This is the second and third door 1
5, 15 ″ can be opened and closed without providing the door opening / closing opening shown below on the furnace wall, whereas the first door 1
5 'is because it is necessary to provide a door opening / closing opening in the furnace wall. That is, a gap may be provided between the heating furnace 11 and the elevating zones 14, 14 '. This gap allows the second and third doors 15 and 15 ″ to be arranged at the front surface of the entrance and exit of the heating furnace and raised and lowered without interfering with other members (for example, the furnace wall). In addition, the space between the heating furnace 11 and the elevating zones 14 and 14 ′ is also a closed space, and providing a door opening / closing opening also in this portion can further stabilize the temperature in the heating furnace, and This is preferable because the transfer of the mold between the lifting zones 14 and 14 ′ can be performed smoothly.

The conveying means in the present invention includes, for example, those for driving a drive chain, a belt, a roller, etc., connected to driving means such as a motor. Any material that can be conveyed intermittently to can be used.

In the heating zone and the slow cooling zone, a plurality of heaters are arranged on a furnace wall made of a heat insulating material, and each zone is heated to a predetermined temperature. The temperature of the heating zone is set according to the type of the glass plate.
It is heated to about 750 ° C. The temperature of the slow cooling zone is set according to the temperature of the heated glass sheet and its model, and is usually set to about 400 to 450 ° C. Note that the inside of the zone can be heated using a burner instead of the heater. All of the above heaters may be replaced by burners, but some may be replaced by burners.

In the above example, the heating furnace is provided with four divided heating zones, but the heating zone can be divided into an appropriate number according to the installation location of the glass sheet forming apparatus of the present invention. If a temperature distribution is given to each heater in each zone and a temperature distribution is given to each part of the glass sheet in accordance with the temperature distribution, the bending shape of the glass sheet can be controlled more precisely. Roughly, since the radius of curvature can be made small in a portion where the temperature of the glass sheet is high, and the radius of curvature can be made large in a portion where the temperature is low, forming a temperature distribution in the glass sheet requires a glass sheet having a desired bent shape. What you can get. Therefore, in order to control this temperature distribution to a desired distribution, the above division is preferably about 4 to 6.

In the slow cooling zone, an appropriate jig is used for elevating means for moving the mold away from the conveying means and placing it again on the cooling zone, such as vertically moving a piston in the zone from outside the zone by an air cylinder or the like. be able to.

[0037]

According to the glass sheet forming apparatus of the present invention,
Between the adjacent heating zone and slow cooling zone in the heating furnace,
Since the first door which opens and closes with the movement of the forming die is provided, it is possible to obtain a glass sheet forming apparatus capable of maintaining the temperature in each zone at a predetermined temperature. Further, a door advance / retreat opening is provided on the furnace wall of the heating furnace corresponding to between the heating zone and the slow cooling zone so that the first door can advance / retreat between the inside of the heating furnace and the outside of the heating furnace, Since the box-like enclosure having an opening on the side of the door advance / retreat opening that covers the door advance / retreat opening from the outside of the heating furnace is in contact with the furnace wall outer surface, heat is released to the outside of the heating furnace with the opening and closing of the door. Can be prevented.

[Brief description of the drawings]

FIG. 1 is an overall schematic sectional view showing an example of a glass sheet forming apparatus of the present invention.

FIG. 2 is a schematic front sectional view of a main part showing an example of an apparatus for forming a glass sheet of the present invention (a), and a schematic sectional view of a main part (b).

FIG. 3 is a schematic partial front sectional view showing an example of a glass sheet forming apparatus of the present invention.

[Description of Signs] 11: Heating furnace 12: Mold return zone 13, 13 ': Lifter 14, 14': Elevating zone 15, 15 ', 15 ": Door 30: Mold 70: Conveying means 80: Enclosure

Claims (3)

[Claims] 1. A tunnel-shaped heating furnace having a plurality of divided heating zones for heating a glass sheet to a forming temperature, and a slow cooling zone arranged downstream of the heating furnace for gradually cooling the glass sheet; A molding unit for conveying a forming die on which a glass plate is placed from an upstream of a heating zone to a downstream of the annealing zone through the plurality of heating zones and the annealing zone; On the furnace wall of the heating furnace corresponding to the zone between the cooling zone and the slow cooling zone, a first door that opens and closes as the mold enters and exits has a door moving forward and backward between the inside of the heating furnace and the outside of the heating furnace. A box-shaped enclosure having an opening on the door advance / retreat opening side is provided on the outer surface of the furnace wall located on the outer periphery of the door advance / retreat opening, and a door advance / retreat is provided on the inner periphery of the opening. To the outside of the heating furnace Provided so as to protrude, the door molding apparatus for a glass plate which is characterized by comprising configured to be housed in the box-like enclosure in its opened state. 2. The method according to claim 1, wherein the conveying means intermittently conveys the molding die to each of the heating zones and the annealing zone, and the residence time of the molding die in each heating zone excluding the heating zone adjacent to the annealing zone. T ₀ is constant, and the residence time T ₁ of the mold in the heating zone adjacent to the slow cooling zone is T
_2. The glass sheet forming apparatus according to claim 1, wherein the first door is opened in accordance with the transfer of the forming die from the heating zone to the slow cooling zone. 3. The heating furnace is provided at an upper stage of a return zone for returning a forming die after the formed glass sheet is recovered to an entrance of the heating furnace, and is provided at an entrance of the heating furnace and an exit of the heating furnace. A first and a second elevating zone having a lifter for elevating and lowering the mold between the return zone and the heating furnace are provided adjacent to each other, and the conveying means moves from the heating furnace to the first and second elevating zones. The first elevating zone and the entrance of the heating furnace extend in accordance with the transfer of the mold from the first elevating zone to the heating zone and the transfer of the mold from the slow cooling zone to the second elevating zone. 3. The glass sheet according to claim 1, wherein a second door disposed between the second opening and a third door disposed between the outlet of the heating furnace and the second elevating zone are opened. Molding equipment.