JPH1029829A - Bending device for glass plate, bending die and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to form a glass plate having a standard shape when assembled to a car body and to improve productivity and yield. SOLUTION: The forming surface 6 of the forming die 5 comprises respective main forming surface parts 6A and respective deformation compensating surface parts 6B. The respective main forming surface parts 6A form the glass plate to a curves surface shape approximately equal to the standard curved surface having a recessing curved shape. The respective deformation compensating surface parts 6B form the formed glass plate 8 to the curved surface of the recessing curved form more deeply recessing from the standard curved surface 9 so as to coincide with a master glass shape 10 when placed on an inspection die.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending apparatus for bending a glass sheet in a heating furnace to form, for example, a windshield or a rear glass of an automobile.

[0002]

2. Description of the Related Art In general, a windshield, a windshield, etc., which is a windshield of an automobile, is required to be curved for automobile design reasons. Therefore, it is necessary to appropriately bend a flat glass sheet. become. As a glass sheet bending apparatus for performing this bending, an apparatus provided with a bending die having a concavely curved forming surface is known. In forming a glass plate by using the bending die, first, the glass plate is cut into a predetermined outer peripheral shape, and the glass plate is placed on a forming surface of the bending die. Then, with the glass plate placed thereon, the bending die is carried into the heating furnace, and the glass plate is heated to the glass softening temperature, and the glass plate is bent and formed by the weight of the glass plate along the forming surface of the bending die. I do. In such a glass sheet bending apparatus, the bending surface of the bending die that determines the curvature of the formed glass sheet is formed into a curved surface that is equal to a prescribed curved surface to be heated and bent.

[0003] On the other hand, the formed glass sheet thus bent is inspected for quality control to determine whether or not it conforms to standards. For this reason, the inspection mold for inspecting the molded glass sheet is a frame mold having the same curvature as the inner surface curvature of the molded glass sheet shape having the specified curved surface, and a predetermined distance or more between the frame mold and the glass plate to be inspected. And a taper gauge for measuring the distance between the glass plate to be inspected and the frame mold. The inspection type configured in this way is
By measuring the distance between the mold and the molded glass plate when the molded glass plate is placed on the frame mold via the spacer,
Inspect whether the curved shape of the formed glass sheet conforms to the standard.

In order to reflect the state when the formed glass plate is assembled to the vehicle body, the spacer may be constituted by a plurality of support pins, and each support pin partially covers the outer peripheral end of the formed glass plate. Inspection is performed in a state where it is supported.

In recent years, many automobiles have a more curved shape. Therefore, as a shape of the windshield for an automobile, a shape in which the outer peripheral edge thereof is greatly curved has been required. Since this windshield is assembled to the vehicle body by the outer peripheral edge, the suitability for this assembly often depends on the curvature of the outer peripheral edge, and it is necessary to strictly control the curvature of the outer peripheral edge. Have been.

In the case where the curvature of the outer peripheral edge is large as described above, if the glass plate is supported on the outer peripheral edge by the above-described inspection-type support pins, the supporting state becomes unstable. Then, each support pin is moved from the outer peripheral end side to the inner peripheral side of the formed glass plate, and the inspection is performed in a state where the outer peripheral end is a free end. By inspecting the shape of the glass plate in this way,
The support of the glass plate on each support pin can be stabilized.

[0007]

By the way, in the above-mentioned prior art glass sheet bending apparatus, since the forming surface of the bending mold is a specified curved surface, the formed glass sheet has a specified curved surface on the bending mold. . However, when the formed glass sheet is placed on the support pins of the inspection mold, the formed glass sheet is deformed by its own weight. Further, since the molded glass sheet is similarly deformed when assembled to a vehicle body, there is a problem that a deviation from a prescribed curved surface occurs.

In the above-described molded glass sheet having a large outer peripheral curvature, the curvature of the glass sheet is more reflected in the curvature in the vicinity of the terminal. The terminal shape cannot be obtained. For this reason, when such a formed glass sheet is assembled to a vehicle body, there is a problem that the suitability for the assembly is reduced. Therefore, when a deviation from the prescribed curved surface occurs in the formed glass sheet having a large curvature at the outer peripheral edge, there is a possibility that sufficient fitting compatibility may not be obtained.

The present invention has been made in view of the above-mentioned problems of the prior art, and provides a glass sheet bending apparatus capable of forming a glass sheet having a standard shape when assembled to a vehicle body and improving productivity and yield. The purpose is to do.

[0010]

In order to solve the above-mentioned problems, a first aspect of the present invention is to provide a heating furnace for heating a glass sheet to a temperature higher than a softening point, and a curved molding for mounting the glass sheet. The present invention is applied to a glass sheet bending apparatus including at least a bending mold having a surface, and a bending mold for bending a glass sheet on a forming surface by being transported in the heating furnace.

A feature of the structure adopted by the invention of claim 1 is that the forming surface is a main forming surface portion having a curved curved surface substantially equal to a prescribed curved surface to be heated and bent as a formed glass plate; The glass sheet is previously bent into a desired shape so as to compensate for the shaped glass sheet to become a glass sheet shape having a prescribed curved surface when the sheet is deformed by being placed on an inspection mold having a convex curved shape. And a deformation compensation surface portion.

According to the above configuration, the glass sheet is heated to a temperature equal to or higher than the softening point in the heating furnace, and the formed glass sheet is heated and bent along the forming surface including the main forming surface portion and the deformation compensation surface portion. At this time, the molded glass sheet was bent with a specified curved surface by the main forming surface portion, and the surface that became the specified curved surface when deformed by placing the formed glass plate on the inspection mold by the deformation compensation surface portion was compensated. It can be bent in the state.

Further, the invention according to claim 2 has a curved forming surface on which a glass plate is placed, and the glass plate is placed on the forming surface and conveyed in a heating furnace, whereby the glass plate is transferred. It is applied to a bending mold of a glass sheet to be bent.

The second aspect of the present invention is characterized in that the forming surface is a main forming surface having a curved surface substantially equal to a prescribed curved surface to be heated and bent as a forming glass plate; The glass sheet is previously bent into a desired shape so as to compensate for the shaped glass sheet to become a glass sheet shape having a prescribed curved surface when the sheet is deformed by being placed on an inspection mold having a convex curved shape. And a deformation compensation surface portion.

According to the above configuration, the formed glass sheet is heated and bent along the forming surface including the main forming surface portion and the deformation compensation surface portion. At this time, the formed glass plate is bent by the main forming surface portion with a specified curved surface, and the surface that becomes the specified curved surface when deformed by placing the formed glass plate on the support pin of the inspection die by the deformation compensation surface portion. Can be bent while compensating for this.

Further, the invention according to claim 3 has a curved forming surface on which a glass plate is placed, and the glass plate is placed on the forming surface and conveyed in a heating furnace, whereby the glass plate is transferred. The present invention is applied to a method for manufacturing a bending mold for a glass sheet to be bent.

The method adopted by the invention according to claim 3 is characterized in that a step of setting a prescribed curved surface to be heated and bent as a molded glass plate, and that the molded glass plate is placed on an inspection mold having a convex curved shape. A step of setting an amount of deformation from the specified curved surface that occurs when the mounting is performed, and a main forming surface portion in which a deformation compensation surface portion in which the amount of the deformation is added to the specified curved surface and a portion having a small amount of deformation remain a specified curved surface shape. And determining a molding surface from the main molding surface portion and the deformation compensation surface portion.

According to the above method, in the prescribed curved surface setting step, the prescribed curved surface to be heated and bent as a formed glass sheet is determined, and in the next deformation amount setting step, the prescribed curved surface set as described above is determined. The amount of deformation from the specified curved surface that occurs when the formed glass plate is placed on the inspection mold having a convex curved shape is determined, and in the forming surface determination step, the portion with a small amount of deformation remains the specified curved surface shape. After the forming surface is determined by providing the forming surface portion and the deformation compensating surface portion in which the amount of deformation is added to the prescribed curved surface, a bending apparatus for a glass sheet can be manufactured.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of a glass sheet bending apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1 to 7 show a first embodiment of the present invention, wherein 1 is a heating furnace for heating a glass plate to a glass softening temperature, and the heating furnace 1 is a rectangular tube made of a heat-insulating refractory material or the like. The inside thereof is provided with a heating section 1A on the inlet side of the furnace and a cooling section 1B on the outlet side. And heating furnace 1
The glass sheet 7 described later conveyed into the inside is heated and bent by the heating unit 1A, and then cooled to about room temperature by passing through the cooling unit 1B to become a formed glass sheet 8.

As shown in FIGS. 2 and 3, reference numeral 2 denotes a heater as a heating source provided in a heating section 1A in the heating furnace 1. The heating source 2 in the heating furnace 1 surrounds a molding die 5 and the like described later. It is provided on the side surface and the upper surface. The heater 2 is made of, for example, an electric heater or a gas burner, and heats the glass plate 7 to a molding temperature (580 to 700 ° C.).

Reference numeral 3 denotes a conveyance path such as a rail extending from the entrance side to the exit side in the heating furnace 1, and the conveyance path 3 is buried in the hearth of the heating furnace 1. Then, a carriage 4 on which a molding die 5 described later is mounted is placed on the transport path 3, and the carriage 4 and the like move on the transport path 3 by a chain conveyor or the like (not shown).

Reference numeral 5 denotes a forming die as a bending die having a concavely curved contour shape, and the forming die 5 has an outer shape of the forming die 5.
The glass plate 7 having a thickness of, for example, 4.6 mm is bent under its own weight by placing the glass plate 7 on the molding surface 6 and transporting the glass plate 7 through the heating furnace 1. For this reason, the upper surface of the molding die 5 is a molding surface 6 having a concave curve. The molding die 5 is formed of a heat-resistant material (for example, stainless steel or the like) that can withstand the molding temperature of the glass sheet in the heating furnace 1.
The molding die 5 is fixed on the trolley 4 via the plurality of columns 4A, and is carried into the heating furnace 1 together with the trolley 4 by a chain conveyor or the like (not shown). At this time, the glass plate 7 placed on the mold 5 is heated by the heater 2 to a glass softening temperature (for example, 550 to 650 ° C.) and softened, and hangs down by its own weight. Then, the glass plate 7 is bent along the forming surface 6 of the forming die 5 and formed into a formed glass plate 8. At this time, the surface of the molded glass plate 8 which is in contact with the molding surface 6 of the molding die 5 is a convexly curved outer surface 8A, and the surface facing the outer surface 8A is a concavely curved inner surface 8B which is assembled to a vehicle body of an automobile. .

Here, the forming surface 6 provided on the upper surface of the forming die 5 has a main forming surface portion 6A and each main forming surface portion 6A which substantially coincide with a specified curved surface 9 which is a design shape of a glass sheet for an automobile as shown in FIGS. Each deformation compensation surface portion 6B is provided between the main molding surface portions 6A.

Each of the main forming surface portions 6A has the same curved surface as the concave curved prescribed curved surface 9 to be heated and bent.
In each of the deformation compensating surface portions 6B, two locations at the upper left ends of the left and right sides have a curvature smaller than the specified curved surface 9 (a concave curved shape that is more shallowly depressed), and the other four locations have larger curvatures than the specified curved surface 9. (Recessed concave shape).

Each deformation compensation surface portion 6B has a deformation amount when a glass plate having a specified curved surface 9 (master glass shape 10) is placed on each support pin 17 of an inspection mold 11 described later. Is estimated in advance, and the curved surface cancels out this deformation amount. For example, when the deformation amount of the glass plate of the master glass shape 10 hanging down by 0.5 mm on the inner surface 8B side on the inspection mold 11 is estimated, the deformation compensation surface portion 6B corresponding to this is configured to move the formed glass plate 8 to the outer surface 8A side. 0.5m
It is formed in a concave curve shape that is depressed deeper than the prescribed curved surface 9 so as to be m-curved.

Here, the deformation amount of the glass plate having the master glass shape 10 on the inspection mold 11 is calculated as follows using a computer and the finite element method. First, the master glass shape 10 is divided into about 500 (preferably 500 or more).
And the position corresponding to each support pin 17 is fixed in the thickness direction. In this state, the amount of deformation is estimated assuming that uniform distribution weights are applied to individual elements.

[0028] Then, the modified compensation surface portion 6B is provided corresponding to between the support pin 17, test type molded glass plate 8 1
It compensates for the molded glass sheet 8 to assume the master glass shape 10 when deformed by being placed on the top 1.

Reference numeral 11 denotes an inspection die arranged on the side of the exit side of the heating furnace 1. As shown in FIGS. 6 and 7, the inspection die 11 comprises a frame die 12, support legs 13 and a base 14 as shown in FIG. Is done. Here, the frame mold 12 is the master glass shape 1
It has the same curvature as the inner surface curvature of 0 and is formed into a convexly curved contour shape by epoxy resin or the like. And the frame mold 1
2 is provided substantially horizontally on a rectangular base 14 via each support leg 13.

An outer trim line 15 of the master glass shape 10 is written on the upper surface of the frame mold 12, and two stoppers 1 are provided on one long side of the outer side of the outer trim line 15.
6, 16 are provided. Furthermore, three pieces each on the long side and one piece on the short side inside the outer trim line 15 for a total of 8
Each of the columnar support pins 17 protrudes. Each support pin 17 reflects the state when the formed glass sheet 8 is assembled to the vehicle body, and manages the curvature of the outer peripheral edge of the formed glass sheet 8 sufficiently.
Is provided at a predetermined location along the outer peripheral edge. Accordingly, each of these support pins 17 is placed on the inspection mold 11 by the forming glass plate 8.
Is placed, a gap equal to or more than a predetermined interval is secured between the molded glass plate 8 and the frame mold 12.

Here, a part of the formed glass sheet 8 carried out of the heating furnace 1 is manually placed on an inspection mold 11 for performing a sampling inspection. At this time, the support pins 17 are attached to the molded glass plate 8 such that the outer peripheral terminals of the molded glass plate 8 correspond to the outer trim lines 15 by the stoppers 16.
Placed on top. Then, it is confirmed whether or not the formed glass sheet 8 satisfies the standard by measuring the gap dimension between the outer peripheral end of the formed glass sheet 8 and the frame mold 12.

The apparatus for bending a glass sheet according to the present embodiment has the above-described configuration. When the forming die 5 is manufactured, first, it should be heated and bent as the formed glass sheet 8 in a prescribed curved surface setting step. The specified curved surface 9 is determined from the design shape of the glass sheet for an automobile.

Next, in the deformation setting step, the formed glass plate 8
The amount of deformation from the prescribed curved surface 9 that occurs when the is placed on each support pin 17 of the inspection mold 11 is determined using a finite element method using a computer. At this time, the master glass shape 10 having the prescribed curved surface 9 is divided into about 500 parts (preferably 50 parts).
(0 division or more), and the position corresponding to each support pin 17 is fixed in the thickness direction, and in this state, the uniform distribution weight is applied to each element.

In the forming surface determination step, each of the main forming surface portions 6A and the deformation amount corresponding to the deformation set in the deformation amount setting step or the portion having a small amount of deformation remain as the specified curved surface 9 are defined. The bending surface of the glass plate can be manufactured after the forming surface 6 is determined by providing each deformation compensation surface portion 6B in consideration of the above.

The glass sheet bending apparatus according to the present embodiment is constructed as described above. Next, the operation of the apparatus will be described with reference to FIGS.

First, a flat glass plate 7 is placed on a molding die 5 and is moved together with the molding die 5 to a heating section 1A in the heating furnace 1 by a carriage 4 moving via a chain conveyor or the like (not shown). Conveyed. In the heating unit 1A, the glass sheet 7 is heated to a glass softening temperature (550 to 650 ° C.) by the heater 2 and softened, and is bent along its forming surface 6 by its own weight or press working. Becomes

At this time, the molding surface 6 includes a main molding surface portion 6A having a concave curved surface equal to the prescribed curved surface 9 and a prescribed curved surface 9A.
Since each of the deformation compensating surfaces 6B has a curved surface having a larger curvature or a smaller curvature, the molded glass plate 8 has a shape in which a portion corresponding to each of the deformation compensating surfaces 6B is deeper or shallower than the master glass shape 10. Molded.

Next, the molded glass plate 8 is conveyed to the cooling section 1B of the heating furnace 1 while being placed on the molding die 5, and is kept for a predetermined time so as not to cause undesired distortion in the molded glass plate 8. It is gradually cooled while moving at a controlled cooling rate, and is taken out of the heating furnace 1 after reaching about room temperature.

Then, a part of the formed glass sheet 8 carried out of the heating furnace 1 is placed on a convexly curved inspection mold 11 by hand to perform a sampling inspection. By measuring the gap size between the mold and the frame 12, it is confirmed whether or not the formed glass sheet 8 satisfies the standard.

At this time, as shown in FIG. 7, the formed glass plate 8 placed on each support pin 17 is deformed by its own weight between the support pins 17 in the direction indicated by the arrow A. Since it is curved in advance by the amount of deformation with respect to the master glass shape 10, when it is placed on the inspection mold 11, the shape becomes the same as the master glass shape 10.

Here, in the comparative example shown in FIG. 8, a case is shown in which the molding surface 18A of the conventionally used molding die 18 is formed as a concave curved surface equal to the prescribed curved surface 9. Formed glass plate 1 bent by this forming die 18
9 has the same shape as the master glass shape 10 on the mold 18. However, the molded glass plate 19 is
When placed on the top, as shown in FIG.
The space between 7 is suspended in the direction of arrow B by its own weight, and is deformed into a concavely curved shape. For this reason, the shape of the formed glass plate 19 does not match the master glass shape 10, and the prescribed curved surface 9 cannot be obtained.

Therefore, when the molded glass plate 19 bent by the conventionally used molding die 18 is assembled to an automobile, the inspection die 11 is weighed by the own weight of the molded glass plate 19.
Since the same deformation as above occurs and the specified curvature can not be obtained,
The fitting suitability of the formed glass sheet 19 is reduced. Further, when a large deformation occurs, the formed glass sheet 19 does not conform to the standard, so that the productivity and the yield are reduced.

On the other hand, the mold 5 according to this embodiment is
Since each deformation compensation surface portion 6B is provided in advance on the molding surface 6 so as to offset the amount of deformation when the glass plate having the master glass shape 10 is placed on the inspection die 11, the molded glass plate 8 is placed on the inspection die 11. When placed, the formed glass plate 8 has the same shape as the master glass shape 10.

Thus, according to the present embodiment, the molding surface 6 of the molding die 5 is composed of the main molding surface portions 6A and the deformation compensation surface portions 6B. The deformation caused by its own weight when it is placed on the inspection mold 11 after being bent into a curved shape can be offset, and even if the molded glass sheet 8 placed on the inspection mold 11 is deformed by its own weight,
Has a prescribed curved surface 9.

In other words, when the molded glass sheet 8 is assembled to the body of an automobile, the master glass shape 10 can be obtained. The fitting suitability of the plate 19 can be reliably improved. Further, since the molded glass sheet 19 surely conforms to the standard, productivity and yield can be improved.

Next, FIGS. 10 and 11 show the second embodiment of the present invention.
In this embodiment, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted.
However, this embodiment is characterized in that the molding surface 22 of the molding die 21 is provided at the center of the molding die 21 in the longitudinal direction.
2A and 22A, and a pair of deformation compensation surfaces 22B and 22B provided on both ends in the longitudinal direction of the molding die 21.

Here, the molding die 21 has a concavely curved contour shape, has the same outer shape as the molding die 21, and a glass plate is placed on the molding surface 22 and conveyed through the heating furnace 1. A 4.6 mm thick formed glass plate 23 is bent under its own weight. For this reason, the forming die 5 is formed of a heat-resistant material (for example, stainless steel or the like) that can withstand the forming temperature of the glass sheet in the heating furnace 1. And each main molding surface portion 22A
Are provided at the center in the longitudinal direction (upper and lower sides in FIG. 10) of the molding die 21 formed in a substantially rectangular shape.
A substantially matches the specified curved surface 24 which is the design shape of the glass sheet for an automobile.

On the other hand, each deformation compensation surface portion 22B is
Are provided at both ends in the length direction (on both the left and right sides in FIG. 10). Then, each deformation compensation surface portion 22B estimates the amount of deformation when the glass plate of the master glass shape 25 having the specified curved surface 24 is placed on each support pin 26 in advance, and a curved surface that cancels out this deformation amount. Has become. Therefore, as shown in FIG. 11, each deformation compensation surface portion 22B is formed to have a curvature smaller than the prescribed curved surface 24, that is, a concave curved surface that is recessed more shallowly than the master glass shape 24.

Thus, in the present embodiment having the above-described structure, substantially the same operation and effect as those of the first embodiment can be obtained.
Is provided at the center in the longitudinal direction of the molding die 21, and each deformation compensating surface 2
Since 2B is provided at both ends in the length direction of the molding die 21, even if deformation such as bending occurs at both ends in the length direction by mounting the formed glass plate 23 on the support pins 26, The formed glass plate 23 can have a prescribed curved surface 24.

Further, since each deformation compensation surface portion 22B is formed with a smaller curvature than the master glass shape 25, both ends in the length direction of the formed glass plate 23 are formed with a smaller curvature than the master glass shape 25. . By mounting the formed glass plate 23 on the support pins 26 in this way, when the formed glass plate 23 is deformed to a large curvature, the formed glass plate 23 can be made to conform to the master glass shape 25. Thus, the formed glass plate 23 can be reliably conformed to the standard.

FIG. 12 shows a third embodiment of the present invention. The feature of this embodiment is that the deformation of the formed glass sheet is compensated when the support pins are arranged on the inner peripheral side of the formed glass sheet. Forming a molding die. In this embodiment, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted.

In the drawing, reference numeral 31 denotes a molding die having a concavely curved contour. The molding die 31 has an outer shape equal to that of the molding die 31, a glass plate is placed on the molding surface 32, and the inside of the heating furnace 1 is moved. By transporting, for example, a glass plate having a thickness of 4 mm is subjected to its own weight bending. The forming die 31 is formed of a heat-resistant material (for example, stainless steel) that can withstand the forming temperature of the glass sheet in the heating furnace 1. And the mold 31
The molding surface 32 of each main molding surface portion 32A and each deformation compensation surface portion 3
Is composed of a 2B, the main molding surface section 32A is substantially aligned with the provisions curved a design shape of the automotive glass plate, the deformation compensation surface portion 32B has a concave curved surface of large curvature than the predetermined curved surface.

Each deformation compensation surface portion 32B estimates the amount of deformation when the master glass-shaped glass plate is placed on each support pin 33 arranged on the inner peripheral side in advance, and cancels out this amount of deformation. It has a curved surface.

Thus, in the present embodiment having the above-described structure, substantially the same operation and effect as those of the first embodiment can be obtained. since providing the respective deformation compensation surface portion 32B to compensate for the deformation when placed on the respective support pins 33 to be, it can be reliably offset the deformation caused in the vicinity of the terminal.

For this reason, even with a glass plate having a large curvature at the outer peripheral edge and the size of the glass plate being more reflected on the curvature near the terminal, a prescribed peripheral terminal shape can be obtained. And
When the molded glass sheet formed by the molding die 31 is assembled to the vehicle body, the suitability for assembling the molded glass sheet can be reliably improved.

In each of the above embodiments, the case where one glass plate is heated and bent has been described as an example. However, the present invention is not limited to this, and two glass plates for laminated glass can be simultaneously formed. The present invention can be applied to the case of bending.

In each of the above-described embodiments, the forming dies 5, 21, and 31 as the bending dies are configured to have the contour shape of the formed glass plate. However, the present invention is not limited to this and is configured to have a planar shape. The bending tool may be a bending tool, and the bending tool may be provided with a hinged end to obtain a sharp curve which cannot be obtained by a normal bending bending technique.

Further, in each of the above embodiments, the glass plate is formed by bending under its own weight by softening the glass plate, but the glass plate is hung horizontally or the upper end is supported by a hanging jig and the glass plate is hung down. In a vertical state, the glass sheet can be conveyed into a heating furnace, and the glass sheet can be press-bent formed by forming the bending mold into a planar shape.

[0059]

As described in detail above, according to the first aspect of the present invention, a bending mold is used for a glass sheet bending apparatus, and the forming surface of the bending mold is heated and bent as a formed glass sheet. The main mold surface having a curved surface substantially equal to the prescribed curved surface to be formed and the deformation compensating surface portion which is previously desirably curved with respect to the prescribed curved surface. Even if it is deformed by its own weight when placed on it, it can be formed into a glass plate shape having a prescribed curved surface. Therefore, when the formed glass sheet is assembled to the body of an automobile, it can be formed into a glass sheet shape having a specified curved surface. Therefore, it is possible to surely improve the fitting suitability of the formed glass sheet. In addition, since the molded glass sheet surely conforms to the standard,
Productivity and yield can be improved.

According to the second aspect of the present invention, the forming surface of the bending mold has a main forming surface portion having a curved surface substantially equal to a curved specified curved surface to be heated and bent as a formed glass plate. Since the glass sheet is constituted by the deformation compensating surface portion which is previously desirably curved with respect to the curved surface, the formed glass sheet is heated and bent along the forming surface including the main forming surface portion and the deformation compensating surface portion. At this time, the formed glass plate is bent by the main forming surface portion with a specified curved surface, and the surface that becomes the specified curved surface when deformed by placing the formed glass plate on the support pin of the inspection die by the deformation compensation surface portion. Can be bent while compensating for this.

Further, according to the third aspect of the present invention, after the specified curved surface and the amount of deformation are set, the deformation compensating surface portion in which the amount of deformation is added to the specified curved surface and the portion having a small amount of deformation are kept in the specified curved surface shape. Since the main molding surface portion is provided, and a manufacturing method of determining a molding surface from the main molding surface portion and the deformation compensation surface portion is adopted, a main glass surface having a curved curved surface substantially equal to a prescribed curved surface to be heated and bent as a molded glass plate is used. Forming glass part and forming glass sheet so as to compensate for forming the glass sheet into a glass sheet having a specified curved surface when deformed by placing it on an inspection mold having a convex curved shape. A bending mold having a forming surface composed of a deformation compensation surface portion that bends a desired shape in advance can be manufactured.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a bending apparatus to which a forming die according to a first embodiment of the present invention is applied.

FIG. 2 is a longitudinal sectional view showing the inside of the heating furnace in FIG.

FIG. 3 is a cross-sectional view of the mold according to the first embodiment in a state where the mold is disposed in a heating furnace, as viewed from the direction of arrows III-III in FIG.

FIG. 4 is a plan view showing a molding die in FIG. 3;

5 is an enlarged cross-sectional view showing the molding die and the molded glass plate in an enlarged manner, as viewed from a direction indicated by arrows VV in FIG.

FIG. 6 is a perspective view showing the inspection mold in FIG. 1;

FIG. 7 is an enlarged cross-sectional view showing a state in which a molded glass plate is placed on the inspection mold, as viewed from the direction of arrows VII-VII in FIG.

FIG. 8 shows a mold according to the prior art as a comparative example.
FIG.

9 is a cross-sectional view substantially similar to FIG. 7, showing a state in which the formed glass sheet manufactured by the comparative example of FIG. 8 is placed on an inspection mold.

FIG. 10 is a plan view similar to FIG. 4, illustrating a mold according to a second embodiment of the present invention.

FIG. 11 is a cross-sectional view showing a forming die and a formed glass sheet according to a second embodiment, as viewed from a direction indicated by arrows XI-XI in FIG. 10;

FIG. 12 is a plan view similar to FIG. 4, showing a mold according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating furnace 5,21,31 Mold (bending mold) 6,22,32 Molding surface 6A, 22A, 32A Main molding surface 6B, 22B, 33B Deformation compensation surface 7 Glass plate 8,23 Molded glass plate 9,24 Specified curved surface 10, 25 Master glass shape 11 Inspection type 17, 26, 33 Support pin

Claims (3)

[Claims] 1. A heating furnace for heating a glass sheet to a temperature equal to or higher than a softening point, and a curved forming surface on which the glass sheet is placed. In a glass sheet bending apparatus provided with at least a bending mold for bending a sheet, the forming surface has a main forming surface portion having a curved curved surface substantially equal to a prescribed curved surface to be heated and bent as a formed glass plate. A glass sheet is previously formed to a desired shape so as to compensate for the shaped glass sheet to become a glass sheet having a prescribed curved surface when deformed by placing the formed glass sheet on an inspection mold having a convex curved shape. A glass sheet bending apparatus characterized by comprising a deformation compensating surface portion curved into a shape. 2. A glass plate having a curved forming surface on which a glass plate is placed, wherein the glass plate is bent by placing the glass plate on the forming surface and transporting the glass plate in a heating furnace. A molding die, wherein the molding surface is a main molding surface portion having a curved curved surface substantially equal to a prescribed curved surface to be heated and bent as a molded glass plate, and the molded glass plate is placed on an inspection mold having a convex curved shape. A deformation-compensating surface portion that bends the glass sheet into a desired shape in advance so as to compensate for the shaped glass sheet to have a glass sheet shape having a prescribed curved surface when deformed by placing. Mold for bending glass plate. 3. A glass plate having a curved forming surface on which a glass plate is placed, wherein the glass plate is bent and formed by placing the glass plate on the forming surface and transporting the glass plate in a heating furnace. A method of manufacturing a molding die, wherein a step of setting a prescribed curved surface to be heated and bent as a molded glass plate, and the prescribed curved surface generated when the molded glass plate is placed on an inspection die having a convex curved shape A step of setting the amount of deformation from, and providing a deformation compensation surface portion in which the amount of deformation is added to the prescribed curved surface and a main molding surface portion in which a portion having a small amount of deformation remains a prescribed curved shape, and the main molding surface portion And a step of determining a forming surface from the deformation compensating surface portion.