JP4052014B2 - Method and apparatus for bending glass plate - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a glass plate bending method and apparatus, and more particularly, to a glass plate bending method and apparatus for bending a glass plate heated to a temperature near a softening point into an arbitrary double curved surface.
[0002]
[Prior art]
In the recent automobile industry, various shapes of glass plates have been required due to diversification of automobile designs. In particular, there is a high need for automobile manufacturers for glass plates (so-called deep wing shapes) whose edges are extremely bent.
[0003]
One way to achieve such a deep bending shape is to drop a heat-softened glass plate onto the ring and perform preforming (bending forming shallower than the actual design), and then press using a mold There is a bending apparatus for performing molding (see US Pat. No. 4,859,225). However, although this type of bending apparatus can suppress the occurrence of optical distortion and wrinkles by pre-forming before the main forming, the actual condition is that it cannot sufficiently cope with the deep bending of the peripheral edge of the glass plate.
[0004]
Further, in order to realize deep bending, when a glass plate is dropped on a deep bent ring, there is a problem that misalignment on the ring is likely to occur and bending accuracy is lowered.
[0005]
In order to solve these problems, it is conceivable to apply a so-called ring with a tilt mechanism. For example, a ring 500 with a tilt mechanism shown in FIG. 9 is a metal member having a frame shape as a whole when viewed from above, and includes a fixed portion 501 (two parts) located in the center and wing portions 502 (2 Parts). That is, in FIG. 9, only the fixing portion 501 on the near side is shown, and a fixing portion having the same configuration is also provided at the back of the sheet. A substantially U-shaped wing portion 502 is pivotally connected to the end portion of each fixing portion via a hinge portion 503 in a top view. And as shown in the figure (b), the peripheral part of the glass plate G can be bent reliably by raising the wing part 502 at the time of press with the mold 504. FIG.
[0006]
[Problems to be solved by the invention]
However, since this type of ring with a tilt mechanism has a structure in which the hinge portion 503 protrudes upward as is apparent from FIG. 9A, this portion is likely to contact the glass plate G locally. Therefore, when the glass plate G is dropped and placed on the ring 500, the surface of the glass plate G is scratched (so-called hinge mark) due to contact with the hinge portion 503, so that the heat-softened glass plate is placed on the ring. Dropping and preforming is nearly impossible. Therefore, conventionally, it has been very difficult to apply a ring with a mechanism to a device that performs preforming by dropping.
[0007]
The present invention has been made in view of such circumstances, and provides a glass sheet bending method and apparatus that simultaneously realizes preforming by dropping and dead weight and deep bending of a peripheral portion using a tilt mechanism. The purpose is to do.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention places a glass plate on a ring with a tilt mechanism having a fixed portion and wing portions pivoted at both ends thereof, and this glass plate has a predetermined molding surface. In the method of bending the glass plate by pressing the mold from below and raising the wing portion, the glass plate that has been heated up to a bendable temperature in advance is arranged inside the ring with the tilt mechanism. A step of performing preforming by its own weight by dropping into the inner mold, and a step of transferring the preformed glass plate on the inner mold from the inner mold to the ring with the tilt mechanism. A glass plate bending method is provided.
[0009]
The present invention also includes a ring with a tilting mechanism having a fixed portion and wing portions pivoted at both ends thereof, and a mold having a predetermined molding surface and capable of moving up and down, with the tilting mechanism. In an apparatus for bending the glass plate by pressing the glass plate placed on the ring from below onto the molding surface of the mold and raising the wing portion, the glass plate is arranged inside the ring with the tilt mechanism. The inner mold includes a placement portion on which the glass plate is placed, and an elevating mechanism for moving the placement portion up and down. The elevating mechanism is lowered. The pressure receiving portion that receives the pressing force of the mold that has come, and a counterweight that applies a biasing force to the placement portion to raise the placement portion to a predetermined standby position, have come down Part of the mold When the pressure receiving portion is pushed, the placing portion is lowered integrally with the mold, and the glass plate is replaced with the ring with the tilt mechanism by the lowering. A bending apparatus is provided.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a glass sheet bending method and apparatus according to the present invention will be described in detail with reference to the accompanying drawings.
[0011]
1 and 2 show an embodiment of a glass sheet bending apparatus according to the present invention. The glass plate bending apparatus 100 mainly includes a heating furnace 10, a forming furnace 20, an air-cooling strengthening apparatus 30, and a carry-out roller conveyor 40 from the upstream side of conveyance of the glass sheet G.
[0012]
The heating furnace 10 is an electric heating furnace having a furnace wall made of refractory bricks and the like, and a ceiling heater 11, a hearth heater 12 and a side wall heater 13 installed on the inner wall surface thereof. Further, a roller conveyor 14 composed of a plurality of heat-resistant silica rollers is installed above the hearth in the heating furnace 10, and the glass plate G conveyed on the roller conveyor 14 is formed into a desired shape by the heater. Heat to possible temperature (650-720 ° C).
[0013]
A forming furnace 20, which is an electric heating furnace similar to the heating furnace 10, is installed at the subsequent stage of the heating furnace 10. Immediately after the glass sheet G is brought in, a hearth for supporting the glass sheet G that has been conveyed by air floating. A bed 21 is installed. As shown in FIG. 2, the hearth bed 21 has a plurality of holes 21a on the mounting surface of the glass plate G, and the glass plate G is floated and supported by blowing heated air from these holes 21a. . On the downstream side of the hearth bed 21, a pair of positioners 22 for positioning the glass plate G supported by air floating is installed.
[0014]
A flat mold 23 (FIG. 2) that can move horizontally in the X direction and in the opposite direction is installed above the hearth bed 21. The flat mold 23 is a surface plate having a size equal to or larger than that of the glass plate G, and a large number of air injection / suction holes are densely formed on the flat lower surface thereof. An air intake (not shown) communicating with these air / suction injection holes is formed in the upper part of the flat mold 23, and a blower (not shown) is connected to the air intake via a damper (not shown) outside the furnace. And air suction means (not shown) are connected. By controlling air suction / injection for each hole 21a, the glass plate G can be supported in a non-contact manner.
[0015]
In addition, an upper molding apparatus 300 including an upper mold 302 to which a duct 304 is connected is installed on the ceiling of the molding furnace 20 subsequent to the hearth bed 21 as shown in FIG. A rail 25 (FIG. 2) is installed under the floor from directly below the upper molding device 300 to the hearth bed 21, and a lower molding device 200 is slidably installed on the rail 25. The hearth 24 is provided with a slit (not shown), and the legs 211 of the lower forming apparatus 200 are attached to the rail 25 through the slit. A shuttle door 26 is slidably installed up and down at the carry-out port of the glass plate G of the molding furnace 20 and is opened and closed according to the passage of the shuttle described later.
[0016]
An air cooling strengthening device 30 for air cooling strengthening of the conveyed glass plate G is installed at the subsequent stage of the forming furnace 20. The air-cooling strengthening device 30 includes a lower air outlet head 31 with the air outlet facing upward, and an upper air outlet head 32 disposed with the air outlet facing downward and facing the lower air outlet head 31. It consists of.
[0017]
Further, an unloading roller conveyor 40 is installed at the subsequent stage of the air-cooling strengthening device 30, and an air for floating the glass plate G on the conveyor on the back side of the unloading roller conveyor 40 immediately after the air-cooling strengthening device 30. A floating device 41 is installed. A stopper 42 for supporting the glass plate G floated by the air floating device 41 and preventing the glass plate G from being blown up is installed above the carry-out roller conveyor 40 facing the air floating device 41.
[0018]
Further, a shuttle 33 for transporting the glass plate G is installed between the carry-out roller conveyor 40 and the air cooling strengthening device 30 so as to be horizontally movable. A quench ring 33a is installed at the upstream end of the shuttle 33, and a catch member 33b is installed at the downstream end. The shuttle 33 is movable along a rail (not shown) installed from the molding furnace 20 to the carry-out roller conveyor 40. By reciprocating between them, the shuttle 33 moves from the molding furnace 20 to the conveying roller conveyor 40 to make glass. The board G is conveyed.
[0019]
Here, the detail of the lower shaping | molding apparatus 200 and the upper shaping | molding apparatus 300 is demonstrated. FIG. 3 is a side view showing details of the lower molding apparatus 200 and the upper molding apparatus 300, and FIG. 4 is a top view of the lower molding apparatus 200. As shown in FIG. 3A, the lower molding apparatus 200 includes a lower mold 220 installed on a gantry 210, an inner mold 230 installed around the lower mold 220 and movable up and down, and an inner mold 230. And a ring 240 with a tilting mechanism installed around.
[0020]
Here, the lower mold 220 supports the central portion of the glass plate G heated in the molding furnace 20 and suppresses the softened glass plate G from being bent excessively.
[0021]
The inner mold 230 includes a support frame 231 erected on the gantry 210, a frame 232 pivoted on the support frame 231, a counterweight 233 fixed to one end of the frame 232, and the other end of the frame 232. The frame 234 is pivotally mounted on the part, the horizontal ring 235 is fixed to one end of the frame 234, and the pressure receiving part 236 is fixed to the frame 234. The horizontal ring 235 is a metal ring-shaped member having a size smaller than the outer shape of the glass plate G before bending and supporting a position slightly inside from the outer periphery of the glass plate G. Further, the horizontal ring 235 has a horizontal shape in a side view, and is covered with a heat resistant cloth or a heat resistant nonwoven fabric made of stainless steel or the like so as not to damage the placed glass plate G.
[0022]
Further, the ring 240 with the tilt mechanism includes a support frame 241 standing on the gantry 210, a fixing portion 242 supported by the support frame 241, a wing portion 244 connected to the fixing portion 242 via a hinge portion 243, The frame 245 is fixed to the wing portion 244. An arm 246 connected to a drive shaft of a servo motor (not shown) is in contact with the end of the frame 245, and the wing 244 is turned inward with the hinge 243 as a fulcrum.
[0023]
On the other hand, the upper molding apparatus 300 stands by above the lower molding apparatus 200. The upper molding apparatus 300 includes an upper mold 302 installed on the gantry 301, a pressing rod 303 erected on the gantry 301, and a duct 304 communicating with the upper mold 302. The upper mold 302 is a metal (cast) mold having a hollow inside, and a surface that contacts the glass plate G (hereinafter referred to as a molding surface) has a predetermined curved shape. An infinite number of holes are formed on the molding surface, and air is sucked into the mold from each hole by suction through the duct 304, and the press-molded glass plate G can be sucked and supported. Conversely, air can be blown out through the duct 304. The molding surface of the upper mold 302 is covered with a heat resistant cloth or a heat resistant nonwoven fabric made of stainless steel or the like.
[0024]
Next, with reference to FIG. 5, the bending process of the glass plate by the bending apparatus shown in FIGS. First, the glass sheet G heated gradually in the heating furnace 10 of FIG. 2 is conveyed to the forming furnace 20 by the roller conveyor 14 (step S1). The glass plate G carried into the forming furnace 20 is placed on the hearth bed 30 installed immediately after the carry-in entrance. Heated air is blown out from the numerous holes 21a provided in the hearth bed 30, and the glass plate G is floated by the blowing force of the air and is supported by air floating.
[0025]
On the other hand, the hearth bed 30 has a downward gradient of about 1 ° toward the front of the glass plate G in the conveying direction (X direction in FIG. 2), and the glass plate G has an inertial force when being carried in by the roller conveyor 14. It advances in the X direction by its own weight. A pair of positioners 22 shown in FIG. 1 stand by at the front end of the glass plate G in the conveyance direction, and abut on the front corners of the glass plate G that has traveled. The positioner 22 appropriately moves in the X or Y direction in FIG. 1 in accordance with an instruction from a control device (not shown) to position the glass plate G on the hearth bed 21.
[0026]
Above the positioned glass plate G, a flat mold 23 for sucking and supporting the glass plate G stands by, and the positioned glass plate G is sucked and supported by the flat mold 23. Thereafter, the flat mold 23 moves horizontally above the lower molding apparatus 200 waiting at the position of the two-dot chain line in FIG. 2 and then stops and releases the suction of the air, whereby the glass plate G is formed into the lower molding apparatus. It is dropped and placed on 200 (step S2). At that time, since the glass plate G is heated and softened to a bendable temperature by the high temperature atmosphere in the forming furnace 20, preliminary shallow bending is performed by the inertial force and its own weight due to dropping.
[0027]
The glass sheet G that has been preformed in this way is conveyed to just below the upper molding apparatus 300 by the lower molding apparatus 200 that moves on the rail 25 and stops (step S3). When the glass plate G arrives directly under the upper forming apparatus 300, the upper forming apparatus 300 is lowered and the wing portion 244 of FIG.
[0028]
That is, when the upper molding device 300 is lowered, the pressing rod 303 first contacts the pressure receiving portion 236 of the lower molding device 200, and the pressing rod 303 presses the pressure receiving portion 236 attached to the inner mold 230 downward. As a result, the horizontal ring 235 on which the glass plate G is placed descends in conjunction with the movement of the upper molding device 300.
[0029]
Further, the frame 232 tilts with the hinge portion of the support frame 231 as a fulcrum, and the counterweight 233 rises. The peripheral portion of the glass plate G protruding from the outer periphery of the horizontal ring 235 is gradually replaced with the fixing portion 242 of the ring 240 with a tilting mechanism, and the wing portion 244 is covered in parallel, so that the glass plate G is completely It is transferred to the ring 240 with the tilt mechanism (step S4). Thereafter, the glass plate G is further sandwiched between the upper mold 302 and the ring 240 that have been lowered, and press molding is performed (step S5).
[0030]
Next, the glass plate G is sucked and supported on the molding surface by sucking through countless holes provided on the molding surface of the upper mold 302, and the upper molding device 300 is raised while opening the wing portion 244 to the outside. Then, while returning the lower shaping | molding apparatus 200 to an upstream side, the quench ring 33a is entered in the shaping | molding furnace 20, and is stopped just under the glass plate G adsorb | sucked to the upper mold 300. FIG.
[0031]
Next, by releasing the suction of the upper mold 300, the glass plate G is dropped and placed on the quench ring 33a. And the glass plate G mounted on the quench ring 33a is carried out of the molding furnace 20, and is carried between the lower blow head 31 and the upper blow head 32 of the air-cooling strengthening device 30, and blows out air from the nozzles of both heads. Thus, the glass plate G is strengthened by air cooling. When the air cooling strengthening is completed, the blowing pressure from the lower blowing head 31 is made higher than that of the upper blowing head 32, the glass plate G is pressed against the lower surface of the upper blowing head 32 by the force of air, and the catch member 33b is made of glass. The glass plate G is received by the catch member 33b by moving it directly under the plate G, weakening the blowing pressure of both heads.
[0032]
Next, the shuttle 33 is moved horizontally, and the glass plate G is conveyed above the air floating device 41. The glass plate G arriving above the air floating device 41 is raised by the air blowing pressure ejected from the air floating device 41, and the shuttle 33 is moved to the molding furnace 20 side while the glass plate G is pressed against the stopper 42. Move horizontally. Next, by releasing the air blowing, the glass plate G is dropped onto the rubber carry-out roller conveyor 40 and conveyed to an inspection process (not shown) by the conveyor 40. Thereafter, the above process is repeated until the production of all the glass plates is completed (step S6).
[0033]
Next, another embodiment of the present invention will be described with reference to the drawings.
[0034]
FIG. 6 shows another embodiment of the inner mold. In the above embodiment, the inner periphery of the glass plate G is first supported by the horizontal ring 235 which is a frame-shaped member. However, as shown in FIG. 6, the two plate-shaped members 222 are mounted on the glass plate G. It may be used as a placement unit. The plate member 221 between the two plate members 222 corresponds to the lower mold 220 in FIG.
[0035]
FIG. 7 is an embodiment using a curved plate 435 that can be raised and lowered instead of using the horizontal ring 235 and the lower mold 220 of FIG. 3. As shown in the figure, a frame 431 is erected on the frame 210, and a frame 432 is pivoted on one end of the frame 431. A counterweight 433 is fixed to one end of the frame 432, and a frame 434 is pivoted to the other end. One end of the frame 434 is fixed to the curved plate 435, and a pressure receiving portion 436 with which the pressing rod 303 abuts is attached to the frame 434. Therefore, the raising / lowering mechanism of the curved plate 435 has the same configuration as the raising / lowering mechanism of the horizontal ring 235, and the curved plate 435 is always positioned at the uppermost standby position by the counterweight 433. The glass plate G is dropped on the curved plate 435 and bent, and the subsequent steps are the same as those in FIGS.
[0036]
FIG. 8 shows an embodiment of an inner mold that receives a glass plate that has been dropped due to preforming. 3A shows the horizontal ring 235 used in FIG. 3, FIG. 2B shows the curved ring 235a, and FIG. 3C shows the curved plate 435 shown in FIG. In the horizontal ring 235, the peripheral edge of the glass plate maintains a horizontal body until press molding. However, by curving a part, it is preferable that the preforming is promoted by its own weight while being conveyed in the molding furnace.
[0037]
In other words, the curved ring 235a has horizontal regions at both ends and a curved region between these regions. Therefore, the dropped glass plate is initially received in the horizontal region, and then the glass plate peripheral portion is bent while adapting to the curved region by its own weight while being conveyed in the molding furnace 20. The curved plate 435 has horizontal regions at both ends, and has a curved region between these regions (the broken line in the figure is on the curved surface). The effect of the curved plate 435 is the same as that of the curved frame 235a.
[0038]
【The invention's effect】
As described above, according to the glass plate bending method and the bending tool according to the present invention, the heated glass plate is first supported by the inner mold. Thereby, the glass plate is bent to some extent by its own weight. Thereafter, the glass plate is supported by the inner mold and the outer mold disposed on the outside. As a result, the glass plate is bent into the final shape. Since the two-stage forming process is performed in this way, cracks are not generated on both side portions of the glass plate G, and a defect called a hinge mark does not occur.
[0039]
In addition, when the glass plate is dropped directly onto the ring with the tilt mechanism, a problem of misalignment is likely to occur.However, when the glass plate is once received with the inner mold as in the present invention, it is replaced with the ring with the tilt mechanism. The problem can be solved, and the bending accuracy can be improved as compared with the prior art.
[Brief description of the drawings]
FIG. 1 is a partially transparent perspective view showing an embodiment of a glass sheet bending apparatus according to the present invention.
FIG. 2 is a side view schematically showing the bending apparatus shown in FIG.
3A is a side view showing a structure of a lower and upper molding apparatus, and FIG. 3B is a side view showing press molding by an upper mold.
FIG. 4 is a top view showing a lower bending apparatus.
FIG. 5 is a flowchart showing an embodiment of a bending process according to the present invention.
FIG. 6 is a top view showing another form of the lower bending apparatus.
7A is a top view showing another embodiment of the inner mold, and FIG. 7B is a top view showing another embodiment of the lower molding apparatus.
FIGS. 8A to 8C are a perspective view and a side view showing another embodiment of an inner mold used for preforming.
9A and 9B are side views showing a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Heating furnace, 11 ... Ceiling heater, 12 ... Hearth heater, 13 ... Side heater, 20 ... Molding furnace, 21 ... Hearth bed, 21a ... Hole, 22 ... Positioner, 23 ... Flat mold, 24 ... Hearth, 25 DESCRIPTION OF SYMBOLS ... Rail, 26 ... Shuttle door, 30 ... Air-cooling strengthening device, 31 ... Lower blower head, 32 ... Upper blower head, 33 ... Shuttle, 33a ... Quench ring, 33b ... Catch member, 40 Unloading roller conveyor, 41 ... Air floating device, 42 ... Stopper, 100 ... Bending molding device

Claims (4)

A glass plate is placed on a ring with a tilt mechanism having a fixed portion and wing portions pivoted at both ends thereof, the glass plate is pressed from below onto a mold having a predetermined molding surface, and the wing portion is covered. In the method of bending the glass plate,
A step of performing preforming by its own weight by dropping a glass plate that has been heated up to a temperature at which bending can be performed in advance into an inner mold that is arranged inside the ring with the tilt mechanism, and
And a step of transferring a preformed glass plate on the inner mold from the inner mold to the ring with a tilt mechanism. The glass plate bending method according to claim 1, wherein the glass plate is dropped and placed on a frame-shaped inner mold, and the preforming by the dead weight is performed while the inner mold is conveyed in a heated atmosphere. A ring with a tilt mechanism having a fixed portion and wing portions pivoted at both ends thereof, and a mold having a predetermined molding surface and capable of moving up and down, and placed on the ring with the tilt mechanism In an apparatus for bending the glass plate by pressing the glass plate against the molding surface of the mold from below and raising the wing part,
An inner mold arranged side by side inside the ring with the tilt mechanism,
The inner mold includes a placement portion on which the glass plate is placed, and a lifting mechanism for moving the placement portion up and down.
The elevating mechanism includes a pressure receiving portion that receives the pressing force of the mold that has been lowered, and a counterweight that applies an urging force for raising the placement portion to a predetermined standby position. Prepared,
When the pressure receiving portion is pushed by a part of the mold that has been lowered, the placing portion is lowered integrally with the mold, and the glass plate is placed on the ring with the tilt mechanism by the lowering. A glass plate bending apparatus characterized by being replaced. The glass plate bending apparatus according to claim 3, wherein the placement portion is a frame-shaped member.

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