JP5673042B2 - Method for bending glass plate and forming apparatus therefor - Google Patents

Description

  The present invention relates to a method for bending a glass plate and a molding apparatus therefor, and more specifically, a glass plate having flexibility in a state where it is not softened by heating, using a molding die having a curved molding surface. The present invention relates to a technique for bending into a curved shape.

  As is well known, a glass plate having a curved shape has been used relatively frequently as a window glass for automobiles or buildings, or a light-transmitting glass for electronic parts. The plate is usually obtained by reheating a flat glass plate to the vicinity of the softening point and applying secondary forming.

  Various methods have been developed and improved as methods for forming the curved glass plate. As a specific example, according to Patent Document 1, for example, a heat-resistant sheet is stretched on a support base of a transport carriage, a glass plate is placed on the heat-resistant sheet, and in this state, in a heating section in the furnace The glass plate is heated to near the softening point and subjected to weight bending by its own weight. After that, the glass plate can be pressed into a desired curved surface together with the heat-resistant sheet between the upper mold and the lower mold of the press mold. It is disclosed.

  Further, for example, in FIG. 4 of Patent Document 2, a heat-resistant sheet (support member) including a flexible porous member 13 and a buffer member 12 covering the porous member 13 is stretched on the frame 4. And a configuration in which the glass plate 3 is press-formed between the molding surface of the upper mold (plunger) 7 and the support surface of the heat-resistant sheet in a state where the glass plate 3 is placed on the heat-resistant sheet. ing. Specifically, the glass plate 3 placed on the curved support surface of the heat-resistant sheet is heated to 700 to 750 ° C. which is the deformation temperature of the glass while moving in the heating furnace 1, and together with the heat-resistant sheet With the central part of the glass plate 3 curved downward, it is interposed between an upper mold 7 having a molding surface composed of a downward convex curved surface and a lower mold 8 that supports the peripheral edge of the heat-resistant sheet from below. The And when the heat-softened glass plate 3 is conveyed between the upper mold | type 7 and the lower mold | type 8, the upper mold | type 7 descend | falls and presses toward the heat-resistant sheet from the glass plate 3, and glass The plate 3 is press-molded between the molding surface of the upper mold 7 and the support surface of the heat-resistant sheet, and the lower mold 8 is in contact with the lower surface of the peripheral edge of the heat-resistant sheet to support the heat-resistant sheet during press molding. ing.

JP 2003-160346 A Japanese Examined Patent Publication No. 46-41320 (Fig. 4)

  By the way, in any of the molding methods disclosed in Patent Documents 1 and 2, after the glass plate before molding is placed on the heat-resistant sheet, the glass plate is heated and softened to cause bending by its own weight, A glass plate is press-molded together with a heat-resistant sheet.

  In this case, if the thickness of the glass plate is more than 1.5 mm, the glass plate before molding that has been heat-softened is theoretically placed in a normal position by its own weight on the curved support surface of the heat-resistant sheet. It is considered that the occurrence of positional deviation is suppressed against external vibration input or the like. However, even in this case, there is a concern that the heat-softened glass plate may be slightly displaced on the heat-resistant sheet when the frame or the like on which the heat-resistant sheet is stretched is conveyed. The

  On the other hand, when the plate thickness of the glass plate is 1.5 mm or less (particularly 0.3 mm or less), the glass plate is deformed by its own weight due to the reduced weight of the glass plate. It becomes impossible to follow the curved support surface shape of the heat-resistant sheet. Therefore, the glass plate and the support surface of the heat-resistant sheet are not in close contact with each other, and the sliding frictional resistance between them is reduced, so that the position holding of the glass plate placed on the heat-resistant sheet is unstable. It becomes.

  And when the glass plate is placed in an unstable state on the heat-resistant sheet in this way, a large shift occurs in the position of the glass plate with respect to the heat-resistant sheet due to external vibration input or the like. If the glass plate is press-molded in a state in which such a positional deviation has occurred, there arises a problem that a curved glass plate having a desired curved shape cannot be obtained.

  In addition, in the method of placing such a thin glass plate on a heat-resistant sheet that is only stretched over a frame or the like as described above and proceeding with heating, the glass plate is thin, so that it is in a softened state. The time required to reach is shortened, and in particular, the periphery of the edge of the glass plate reaches the softened state in a very short time. For this reason, there is a large difference in the degree of softening between the periphery of the edge of the glass plate and the central portion, and this causes a problem that the glass plate is distorted.

  From the above viewpoints, the problem of the present invention is that, even for a thin glass plate, a difference in softening occurs due to the positional deviation of the glass plate when bending using a forming die and the difference in the portion of the glass plate. This is to suppress the occurrence of distortion of the glass plate.

  The method according to the present invention, which was created to solve the above problems, is a method of bending a glass plate that is flexible without being softened by heating, using a mold having a curved molding surface. In the bending method, the glass plate that has not been heat-softened is held in advance on the molding surface of the molding die that has not been heated to the temperature required for molding, and then the molding die is molded. It is characterized in that the glass plate is heated and softened by heating to a required temperature, and the glass plate is formed into a curved shape following the forming surface.

  According to such a method, before the glass plate is heated and softened, the glass plate is placed along the molding surface of the mold in advance, and then the state is maintained and the mold (or the glass plate and the mold is formed). The mold is heated to soften the glass plate by heating. Thereby, in the previous stage of heat softening of the glass plate, the glass plate can be positioned in advance so as to follow an accurate position with respect to the molding surface of the mold, and the accurate position is maintained. Since it can heat, the factor which a position shift with respect to the molding surface of a glass plate can be reduced as much as possible. In addition, during heating, the transfer of heat to the glass plate depends exclusively on the exchange between the mold and the glass plate, so that the temperature distribution during the heating of the glass plate is less likely to occur. As a result, the situation where the periphery of the edge of the glass plate is softened in a shorter time than the center, and the situation where a large difference appears in the degree of softening between the periphery of the edge and the center due to this. Is less likely to occur. As a result, since the entire area of the glass plate is heated uniformly and an unduly different degree of softening is not caused, it is possible to effectively avoid the problem that the glass plate is distorted. From the above viewpoints, this bending method is advantageous in obtaining a high-quality curved glass plate, and can provide a remarkable effect particularly when bending a thin glass plate.

  In this case, the glass plate is preferably covered with a heat-resistant sheet on one side or both sides.

  In this way, for example, when the glass plate that has not been heat-softened is held in advance on the molding surface of the molding die (molding surface formed of a convex curved surface), the surface of the glass plate with the heat-resistant sheet is maintained. It is possible to cover the side and press the glass plate against the molding surface by the tension of the heat-resistant sheet. Thereby, it is possible to configure a device required for molding from a single mold and a heat-resistant sheet. Further, instead of or together with such an operation, for example, with the heat-resistant sheet interposed between the molding surface of the mold and the glass plate, the glass plate is pressed against the molding surface. can do. Thereby, the trace of a mold from a shaping | molding die is not attached to the back surface of a glass plate, and it becomes possible to obtain the curved glass plate excellent in surface property.

  Examples of the heat-resistant sheet used in this case include woven fabric or felt made of aramid fiber, glass fiber, silica fiber, metal fiber, ceramic fiber, or a mixture thereof.

  Such a heat-resistant sheet is sufficient in terms of heat resistance as well as strength and flexibility.

  In the above method, as the mold, only one mold having a molding surface in which the curved surface is a convex curved surface may be used.

  If it does in this way, after using a pressing member, such as a heat-resistant sheet, for example, holding a glass plate so that it may follow along beforehand, it will be softened by heating, and the glass plate Can be formed into a curved surface shape following the molding surface, so that the apparatus required for molding can be simplified and the number of parts can be reduced.

  Further, in the above method, after forming the glass plate into a curved shape that follows the molding surface formed of the curved surface of the molding die, the glass plate is placed on the molding surface of the molding die and another molding die facing the molding die. You may make it finish-mold by inserting | pinching between shaping | molding surfaces.

  In this way, the curved glass plate once bent is subjected to finish molding by a pair of molds, so that a curved glass plate having a more precise curved surface is obtained, and both the front and back surfaces are obtained. Thus, the temperature distribution can be made more uniform, and abnormal deformation such as warping can be corrected. In addition, when performing finish shaping | molding with a pair of shaping | molding die, it is preferable to cover the front and back both surfaces of a curved glass plate with a heat resistant sheet.

  Further, in the above method, a pair of molding dies each having a convex curved surface and a corresponding concave curved surface are used as the molding dies, and the glass plate is placed between the molding surfaces of these molding dies. After being kept in a state of being preliminarily aligned with the molding surface, it may be molded into a curved shape following the molding surface by the heat softening.

  In this way, even if the glass plate is not pressed against the molding surface of one mold, the glass plate is simply moved between the molding surfaces of the pair of molds by interposing the glass plates between them. Can be held in a state along the molding surfaces in advance. Then, after this, the glass plate is softened by heating, and a curved glass plate having a curved shape following both molding surfaces is obtained. Also in this case, it is preferable that both front and back surfaces of the glass plate are covered with a heat-resistant sheet.

  In the above method, when the plate thickness of the glass plate is 1.5 mm or less, the above-described useful effect is exhibited.

  In addition, if the plate | board thickness of a glass plate is 0.8 mm or less, a bigger effect will be exhibited, and if it is 0.2 mm or less, a curved glass plate with a deeper depth will be appropriate using the softness | flexibility. Further effects such as being able to be manufactured can be exhibited.

  On the other hand, an apparatus according to the present invention, which was created to solve the above technical problem, bends a flexible glass plate that is not heat-softened by using a mold having a curved molding surface. In the glass plate bending apparatus configured to perform the molding in a state in which the glass plate that has not been softened by heating is placed in advance on the molding surface of the mold that has not been heated to the temperature required for molding. It is characterized in that the mold is heated to a temperature required for molding and the glass plate is heated and softened so that the glass plate is formed into a curved shape following the molding surface.

  Since the configuration of this device is substantially the same as the configuration of the method described at the beginning of the method according to the present invention described above, the explanation items including the operational effects are substantially the same as the explanation items already described for the method. Are identical.

  As described above, according to the present invention, before the glass plate is heated and softened, the glass plate can be positioned in advance so as to follow the exact position of the molding surface of the mold, and the exact position can be determined. Since it can maintain and heat, the factor which a position shift with respect to the molding surface of a glass plate can be reduced as much as possible. In addition, during heating, since the transfer of heat to the glass plate depends exclusively on the exchange between the mold and the glass plate, the temperature distribution during the heating of the glass plate is less likely to occur, and the glass plate Therefore, it is possible to effectively avoid the problem that distortion occurs.

FIGS. 1A to 1D are schematic longitudinal sectional front views showing the overall configuration of a glass sheet bending apparatus (implementation status of the bending method) according to the first embodiment of the present invention. FIGS. 2A to 2D are schematic longitudinal sectional front views showing the overall configuration of a glass sheet bending apparatus (implementation status of the bending method) according to the second embodiment of the present invention. 3A to 3C are schematic longitudinal sectional front views showing the entire configuration of a glass sheet bending apparatus (implementation status of the bending method) according to the third embodiment of the present invention. FIGS. 4A to 4C are schematic longitudinal front views showing the overall configuration of a glass sheet bending apparatus (implementation status of the bending method) according to the fourth embodiment of the present invention. FIGS. 5A to 5C are schematic longitudinal front views showing the overall configuration of a glass sheet bending apparatus (implementation status of the bending method) according to the fifth embodiment of the present invention. It is a schematic front view for demonstrating Example 1 of this invention. It is the schematic for demonstrating Example 2 of this invention. It is a schematic front view for demonstrating Example 3 of this invention. It is the schematic for demonstrating Example 4 of this invention.

  Hereinafter, a glass sheet bending method and apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the following embodiments, a glass plate having a plate thickness of 0.2 mm or less is a molding target.

  1A to 1D illustrate a bending apparatus 1 (implementation status of a bending method) according to the first embodiment of the present invention. As shown in FIG. 1A, the bending apparatus 1 includes, as main components, a first heat-resistant sheet 3 on which a glass plate 2 as a molding object is placed, and a first heat-resistant sheet 3 that covers the upper side of the glass plate 2. 2 It has the heat-resistant sheet 4 and the single shaping | molding die 5 by which the molding surface 5a which is arrange | positioned under these heat-resistant sheets 3 and 4 and which consists of a convex curved surface was turned up.

  Each of the first heat-resistant sheet 3 and the second heat-resistant sheet 4 is composed of a woven fabric or felt made of aramid fiber, glass fiber, silica fiber, metal fiber, ceramic fiber, or a mixture thereof. Therefore, these heat resistant sheets 3 and 4 are excellent not only in heat resistance but also in strength and flexibility.

  The outer end portion (outer peripheral end portion) of the second heat-resistant sheet 4 is gripped by a plurality of gripping means 6 that apply a tensile force (tension) to the sheet 4. The gripping means 6 can also be configured by a single member that surrounds and grips the outer periphery of the second heat-resistant sheet 4, and is configured by, for example, a pair of members that grip both ends in the left-right direction. You can also. Further, although not shown, the outer end portion (outer peripheral end portion) of the first heat-resistant sheet 3 is also gripped by gripping means having the same configuration, but the tension that causes the gripping means to act on the first heat-resistant sheet 3. The force may be different from the tensile force that the gripping means 6 acts on the second heat-resistant sheet 4.

  The glass plate 2, the first and second heat-resistant sheets 3, 4 and the mold 5 are heated at a high temperature at which the glass plate 2 is heated and softened from a low temperature atmosphere in which the glass plate 2 is not heated and softened (a low temperature atmosphere lower than the temperature required for bending). It is housed in a furnace capable of adjusting the temperature up to the atmosphere (high temperature atmosphere that is the temperature required for bending). The mold 5 is installed in the furnace in a stationary state, and the molding surface 5a of the mold 5 is not only curved in the left-right direction in FIG. The contour shape of the molding surface 5a in plan view is a circle (including an ellipse) or a rectangle. Note that the molding surface 5a may be curved only in one direction.

  Next, the operation of the bending apparatus 1 having the above-described configuration (glass plate bending method) will be described.

  First, the glass plate 2 held by the first and second heat-resistant sheets 3 and 4 is put into a furnace in a low-temperature atmosphere in which the forming die 5 is accommodated in a state of room temperature or preheated. As shown to 1 (a), it arrange | positions at right above the shaping | molding die 5, and is arrange | positioned. And when the inside of the furnace is maintained in a low temperature atmosphere, the first and second heat-resistant sheets 3 and 4 move downward, so that the glass plate 2 becomes the first heat-resistant sheet as shown in FIG. 3 is pressed against the molding surface 5 a of the mold 5.

  Under such a state, the second heat-resistant sheet 4 covering the glass plate 2 from the front side is from the front side outer end portion (front side outer peripheral end portion) 5aa of the mold 5 from the virtual extension surface 5ax of the molding surface 5a. Also, the glass plate 2 is pulled by the gripping means 6 so as to be bent toward the back side, whereby the glass plate 2 is in a form along the molding surface 5a in advance. In other words, the second heat-resistant sheet 4 is an aspect that wraps the molding die 5 from the molding surface 5a side by the tension (or an aspect that wraps the molding surface 5a of the molding die 5). By pressing the region against the molding surface 5a, the glass plate 2 is in a state of being attached to the molding surface 5a. In addition, about the 1st heat resistant sheet 3, it is maintained in the state closely_contact | adhered to the shaping | molding surface 5a in the state which does not produce distortion, such as a wrinkle, by being pulled by the holding means and giving tension.

  When such an operation is performed, the glass plate 2 is positioned so as to be along an accurate position with respect to the molding surface 5 a of the mold 5. And as shown in the figure (c), the state which the whole area of the glass plate 2 was reliably pressed by the tension | tensile_strength of the 2nd heat-resistant sheet | seat 4 against the shaping | molding surface 5a of the shaping | molding die 5 is maintained, and the inside of a furnace is high temperature atmosphere By doing, while the shaping | molding die 5 is heated, the glass plate 2 is heat-softened. Thus, since the glass plate 2 is heated and softened while maintaining the accurate position that has already been positioned, even if vibration or the like is input from the outside, an unjustified positional deviation with respect to the molding surface 5a of the glass plate 2 occurs. There is nothing.

  In addition, during this heating, the transfer of heat to the glass plate 2 depends solely on the exchange between the mold 5 and the glass plate 2, so that the temperature distribution during the heating of the glass plate 2 is biased. It becomes difficult. As a result, the situation in which the periphery of the edge of the glass plate 2 is softened in a shorter time than the center, and a large difference in the degree of softening appears between the periphery of the edge and the center due to this. Things are hard to happen. As a result, the temperature of the glass plate 2 is increased uniformly over the entire area, so that an undue difference in the degree of softening is eliminated, so that the problem of distortion occurring in the glass plate 2 is effectively avoided.

  Moreover, since the pressing force by the second heat-resistant sheet 4 acts sufficiently over the entire area of the glass plate 2, insufficient stretching or the like hardly occurs around the edge portion of the softened glass plate 2. Therefore, the glass plate 2 is fixed to the planned curved shape in a state where the restoring force (internal restoring force) is surely disappeared over the entire area.

  At the time of this bending, the front and back surfaces of the glass plate 2 are covered by the two heat-resistant sheets 3 and 4, so that the front and back temperatures of the glass plate 2 can be evenly dispersed. Since the mold trace from the molding surface 5a of the mold 5 is not attached to the back surface of the glass plate 2, the quality of the glass plate 2 can be improved.

  After this, the glass plate 2 which has been bent is carried out from the furnace while being held by the first and second heat-resistant sheets 3 and 4, and then the first and second heat-resistant sheets 4 are peeled off. For example, the glass plate 2 finally obtained is not distorted and has a thin shape, but the positional deviation with respect to the molding surface 5a of the molding die 5 does not occur. It becomes a curved shape that exactly matches.

  In this case, as shown in FIG. 1C, after the mold 5 is heated and the glass plate 2 is heated and softened in the furnace, the glass plate 2 is bent into a curved shape following the molding surface 5a. As shown in FIG. 1 (d), the other bending mold 7 having the concave curved surface 7a corresponding to the molding surface 5a is used to perform final bending molding (post-molding). May be.

  In this way, the temperature distribution on both the front and back surfaces of the glass plate 2 can be made more uniform, abnormal deformation such as warpage can be corrected, and a glass plate having a more precise curved surface is finally obtained. The other mold 7 in this case may be a ring mold having a molding surface opposed to the outer peripheral portion of the molding surface 5a.

  In the above description of the present embodiment, as a measure for changing from the state shown in FIG. 1A to the state shown in FIG. However, apart from this, the height of the gripping part of the first and second heat-resistant sheets 3 and 4 is held at a fixed position (the holding part can be moved in the horizontal direction). ) And the mold 5 is moved up, the same action can be performed. In addition, the mold 5 can be moved up, and the first and second heat-resistant sheets 3 and 4 can be moved down.

  2A to 2D illustrate a bending apparatus 1 (implementation state of a bending method) according to the second embodiment of the present invention. The bending apparatus 1 according to the second embodiment differs from that according to the first embodiment described above in that the glass plate 2 is placed on the second heat-resistant sheet 4 and the glass plate 2 This is the point where the molding die 5 with the molding surface 5a facing downward is disposed at a position separated directly above. Accordingly, in the furnace, the first and second heat-resistant sheets 3 and 4 are moved up so that the state shown in FIG. 2A is changed to the state shown in FIG. And the effect of softening the glass plate 2 in a high-temperature atmosphere so that the state shown in FIG. 5C is changed to the state shown in FIG. As shown in FIG. 4D, the effect obtained by performing the final bending using another molding die 7 having a molding surface 7a having a concave curved surface is the same as in the case of the first embodiment described above. Are the same. In addition, about the common component requirement of the bending apparatus 1 which concerns on this 2nd Embodiment, and the bending apparatus 1 which concerns on the above-mentioned 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. In this case, in the bending apparatus 1 according to the second embodiment, the lower side is the front side of the mold 5 and the upper side is the back side of the mold 5. In the second embodiment, the first heat-resistant sheet 3 may be attached and fixed to the molding surface 5a in a state where tension is applied to the first heat-resistant sheet 3 and no wrinkles are generated. May not be provided.

  FIGS. 3A to 3C illustrate a bending apparatus 1 (implementation status of the bending method) according to the third embodiment of the present invention. The bending apparatus 1 according to the third embodiment is different from that according to the first embodiment described above in that the front and back surfaces of the glass plate 2 are covered as shown in FIG. 1. A ring mold 8 having a molding surface 8a having a concave curved surface corresponding to the periphery of the edge of the molding surface 5a of the molding die 5 is disposed at a position spaced above the first and second heat-resistant sheets 3 and 4. As shown in FIG. 4B, the ring mold 8 is lowered after the first and second heat-resistant sheets 3 and 4 are moved down and the glass plate 2 is clung to the molding surface 5a of the mold 5. The point which moves and presses the periphery of the edge part of the glass plate 2, and the state where the ring mold 8 pressed the periphery of the edge part of the glass plate 2 is maintained as shown in FIG. This is because the glass plate 2 is heated and softened by setting the inside to a high temperature atmosphere. Therefore, in addition to the pressing force due to the tension of the second heat-resistant sheet 4, the pressing force by the ring mold 8 acts on the periphery of the edge portion of the glass plate 2. Thereby, the periphery of the edge part of the glass plate 2 is softened by heating in a state where it is reliably pressed by the molding surface 5 a of the mold 5. In addition, about the common component of the bending apparatus 1 which concerns on this 3rd Embodiment, and the bending apparatus 1 which concerns on the above-mentioned 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. In the third embodiment, the ring mold 8 is used to press the periphery of the edge of the glass plate 2 in the previous stage of the heat softening of the glass plate 2, but separately, the heat softening of the glass plate 2 is performed. The ring mold 8 may be used in a later bending process (post-molding).

  4A to 4C illustrate a bending apparatus 1 (implementation state of the bending method) according to the fourth embodiment of the present invention. The bending apparatus 1 according to the fourth embodiment differs from that according to the third embodiment described above in that the glass plate 2 is placed on the second heat-resistant sheet 4 and the glass plate 2 The point where the molding die 5 with the molding surface 5a facing downward is arranged at a position separated directly above, and the point where the ring mold 8 with the molding surface 8a facing upward is arranged at a position separated directly below the glass plate 2. . Accordingly, in the furnace, the first and second heat-resistant sheets 3 and 4 are moved up so that the state shown in FIG. 4A is changed to the state shown in FIG. And the operation and effect obtained by moving the ring mold 8 upward thereafter are the same as those in the third embodiment. In addition, about the common component of the bending apparatus 1 which concerns on this 4th Embodiment, and the bending apparatus 1 which concerns on the above-mentioned 3rd Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. In this case, in the bending apparatus 1 according to the fourth embodiment, the lower side is the front side of the mold 5 and the upper side is the back side of the mold 5. Also in the fourth embodiment, the first heat-resistant sheet 3 may be attached and fixed to the molding surface 5a in a state where no tension is applied to the first heat-resistant sheet 3, or the first heat-resistant sheet 3 is used. 3 may not be provided. Also in the fourth embodiment, the ring mold 8 is used to press the periphery of the edge of the glass plate 2 before the heat softening of the glass plate 2. The ring mold 8 may be used in finish bending after heat softening (post-molding).

  5A to 5C illustrate a bending apparatus 1 (implementation status of the bending method) according to the fifth embodiment of the present invention. The bending apparatus 1 according to the fifth embodiment is different from that according to the above embodiment in addition to a mold 5 (hereinafter referred to as an upper mold) 5 having a molding surface 5a made of a convex curved surface. When a molding die (hereinafter referred to as a lower die) 5 'having a molding surface 5a' formed of a concave curved surface corresponding to the molding surface 5a is provided, and when the inside of the furnace is in a low-temperature atmosphere, it is shown in FIG. Thus, from the state in which the glass plate 2 placed on the second heat-resistant sheet 4 and covered with the first heat-resistant sheet 3 is interposed between the upper mold 5 and the lower mold 5 ′, FIG. As shown in (b), the upper die 5 and the lower die 5 'are moved closer to each other to press-mold the glass plate 2, and as shown in FIG. The state in which the mold 5 and the lower mold 5 ′ are pressed by the molding surfaces 5a and 5a ′ is maintained and is shown in FIG. A is a point for heating and softening the glass plate 2 by the furnace to a high temperature atmosphere. Note that, tension is applied to the first and second heat-resistant sheets 3 and 4 under the states shown in FIGS. And the effect at the time of heat softening of this glass plate 2, the advantage of the glass plate 2 finally obtained, etc. are the same as that of the case in the above-mentioned 1st Embodiment. In addition, about the common component requirement of the bending apparatus 1 which concerns on this 5th Embodiment, and the bending apparatus 1 which concerns on each above-mentioned embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the above embodiment, the glass plate 2 having a thickness of 0.2 mm or less is the object to be molded. However, even the glass plate 2 having a thickness of about 1.5 mm is suitably bent by the bending apparatus 1 according to the present invention. Can be done.

  In the above embodiment, the mold 5 (5 ′) and the glass plate 2 are both heated in the furnace at the same time. However, only the mold 5 (5 ′) is heated. The plate 2 may be heated and softened.

[Example 1]
As Example 1 of the present invention, the following specific method was tried. That is, the glass plate 2 is soda glass having a softening point of about 750 ° C. and a plate thickness of 0.2 mm, and the mold 5 is made of stainless steel, and As the first and second heat-resistant sheets 3 and 4, stainless steel fibers knitted were used. In this case, as shown in FIG. 6, the molds include an upper mold 5 with a convex curved surface 5 a facing downward, and a lower mold 5 ′ with a concave curved curved surface 5 a ′ facing upward. These molding surfaces 5a and 5a 'are cylindrical curved surfaces having a radius of curvature of 1000 mm.

  And first, as shown by the code | symbol A in FIG. 6, while mounting the flat glass plate 2 on the 2nd heat resistant sheet 4 by cold (in room temperature), as shown by the code | symbol B in the same figure, The surface of the glass plate 2 is covered with the first heat-resistant sheet 3, and then the glass plate 2 held by the first and second heat-resistant sheets 3 and 4 is in a low-temperature atmosphere, as indicated by reference numeral C in FIG. It puts in in the furnace 9 and interposes between the upper mold | type 5 and lower mold | type 5 '. And when the inside of the furnace 9 is in a low temperature atmosphere, as shown by the symbol D in the figure, the glass plate 2 is formed by pressing the glass plate 2 by moving the upper mold 5 and the lower mold 5 'closer to each other. A state along the surfaces 5a and 5a ′ is assumed. Furthermore, while maintaining this state, as indicated by symbol E in the figure, the furnace 9 is heated to a high temperature atmosphere near the softening point, whereby the upper mold 5 and the lower mold 5 'are heated and the glass plate 2 is heated. Is bent by heating and softening. When this bending is completed, the glass plate 2 taken out from the furnace 9 exactly matches the curved shape of the molding surfaces 5a and 5a 'and is distorted, as indicated by symbol F in FIG. It was confirmed that there was no high-quality curved glass plate 2.

[Example 2]
As Example 2 of the present invention, the following specific method was tried. That is, the glass plate 2 is a non-alkali glass having a softening point of about 950 ° C. and a plate thickness of 0.1 mm, and the mold 5 is made of stainless steel, and As the first and second heat-resistant sheets 3 and 4, those woven with silica fibers were used. In this case, as shown in FIG. 7, only the lower mold 5 with the molding surface 5a made of a convex curved surface facing upward is used as the molding die, and the convex curved surface of the lower mold 5 has a cylindrical radius of curvature of 700 mm. It is a curved surface.

  First, as shown by a symbol A in FIG. 7, the glass plate 2 is placed on the first heat-resistant sheet 3 and the surface thereof is covered with the second heat-resistant sheet 4, and the furnace is in a low temperature atmosphere. 9 is placed and spaced apart directly above the lower mold 5. From this state, as indicated by reference numeral B in the figure, the first and second heat-resistant sheets 3 and 4 are moved downward, and the glass plate 2 is moved to the molding surface 5 a of the lower mold 5 by the tension of the second heat-resistant sheet 4. Keep it along. Thereafter, this state is maintained, and the lower mold 5 is heated and the glass plate 2 is heated and softened by setting the interior of the furnace 9 to a high temperature atmosphere near the softening point, as indicated by C in the figure. Bending. In addition, the glass plate 2 taken out from the furnace 9 after the bending was completed was a high-quality curved glass plate 2 that exactly matched the curved shape of the molding surface 5a and had no distortion.

[Example 3]
As Example 3 of the present invention, the following specific method was tried. That is, the glass plate 2 is an alkali-free glass having a softening point of about 950 ° C. and a plate thickness of 0.2 mm, and the mold 5 is made of stainless steel, and As the first and second heat-resistant sheets 3 and 4, those woven with silica fibers were used. In this case, as shown in FIG. 8, the mold is composed of a lower mold 5 having a convex molding surface 5 a facing upward and a ring mold 8 disposed above the lower mold 5. The convex curved surface is a cylindrical curved surface having a curvature radius of 700 mm.

  First, as shown by a symbol A in FIG. 8, the glass plate 2 is placed on the first heat-resistant sheet 3 and the surface thereof is covered with the second heat-resistant sheet 4. 9 and placed between the lower mold 5 and the ring mold 8. From this state, as indicated by reference numeral B in the figure, the first and second heat-resistant sheets 3 and 4 are moved downward, and the glass plate 2 is moved to the molding surface 5 a of the lower mold 5 by the tension of the second heat-resistant sheet 4. The ring mold 8 is also moved downward and pressed around the edge portion of the glass plate 2 while being in a state of being aligned. Thereafter, this state is maintained, and the lower mold 5 and the ring mold 8 are heated by making the inside of the furnace 9 a high temperature atmosphere near the softening point, as indicated by symbol C in FIG. Bending with softening by heating. In addition, the glass plate 2 taken out from the furnace 9 after the bending was completed was a high-quality curved glass plate 2 that exactly matched the curved shape of the molding surface 5a and had no distortion.

[Example 4]
As Example 4 of the present invention, the following specific method was tried. That is, the glass plate 2 is a non-alkali glass having a softening point of about 950 ° C. and a plate thickness of 0.1 mm, and the mold 5 is made of stainless steel, and As the first and second heat-resistant sheets 3 and 4, those woven with silica fibers were used. In this case, as shown in FIG. 9, only the upper mold 5 having a convex curved surface 5a facing downward is used as the mold, and the convex curved surface of the upper mold 5 has a cylindrical radius of curvature of 700 mm. It is a curved surface.

  First, as shown by a symbol A in FIG. 9, the glass plate 2 is placed on the second heat resistant sheet 3 and the surface thereof is covered with the first heat resistant sheet 4. 9 is placed and spaced apart from the upper die 5. From this state, the first and second heat-resistant sheets 3 and 4 are moved upward as indicated by the symbol B in the same figure, and the glass plate 2 is moved to the molding surface 5a of the upper mold 5 by the tension of the second heat-resistant sheet 4. Keep it along. Thereafter, this state is maintained, and the upper mold 5 is heated and the glass plate 2 is heated and softened by setting the inside of the furnace 9 to a high temperature atmosphere near the softening point, as indicated by reference numeral C in FIG. Bending. In addition, the glass plate 2 taken out from the furnace 9 after the bending was completed was a high-quality curved glass plate 2 that exactly matched the curved shape of the molding surface 5a and had no distortion.

DESCRIPTION OF SYMBOLS 1 Bending apparatus 2 Glass plate 3 Heat-resistant sheet (1st heat-resistant sheet)
4 Heat-resistant sheet (second heat-resistant sheet)
5 Mold (mold with a convex surface)
5a Molding surface (molding surface consisting of convex curved surface)
5 'mold (mold with a concave curved surface)
5a 'molding surface (molding surface consisting of concave curved surface)
6 Grasping means 7 Other molding die (molding die having a molding surface comprising a concave curved surface)
7a (Molding surface consisting of concave curved surface)
8 Ring Mold 8a Molding Surface 9 Consisting of Concave Curve of Ring Mold 9 Heating Furnace

Claims (8)

In a glass sheet bending method in which a flexible glass plate is not heated and softened by using a mold having a curved molding surface,
The glass plate that has not been heated and softened is held in advance on the molding surface of the mold that has not been heated to the temperature required for molding, and then the mold is heated to the temperature required for molding. And a glass plate bending method, wherein the glass plate is heated and softened, and the glass plate is formed into a curved shape following the forming surface.   2. The glass plate bending method according to claim 1, wherein one side or both sides of the glass plate are covered with a heat-resistant sheet.   3. The glass plate bending method according to claim 2, wherein the heat-resistant sheet is a woven fabric or felt made of aramid fiber, glass fiber, silica fiber, metal fiber, ceramic fiber, or a mixture thereof.   The glass plate bending method according to any one of claims 1 to 3, wherein only one forming die having a forming surface whose curved surface is a convex curved surface is used as the forming die.   After the glass plate is molded into a curved shape that follows the molding surface formed of the curved surface of the mold, the glass plate is sandwiched between the molding surface of the molding die and the molding surface of another molding die facing the molding plate. The glass plate bending method according to any one of claims 1 to 4, wherein the glass plate is subjected to finish molding.   A pair of molding dies each having a convex curved surface and a concave curved surface corresponding thereto are used as the molding dies, and the glass plate is pre-aligned with the molding surface between the molding surfaces of these molding dies. The glass plate bending method according to any one of claims 1 to 3, wherein the glass plate is formed into a curved surface shape following the forming surface by the heat softening after being held in a state.   The plate | board thickness of the said glass plate is 1.5 mm or less, The bending forming method of the glass plate in any one of Claims 1-6 characterized by the above-mentioned. In a glass plate bending apparatus configured to bend a glass sheet having flexibility even when not softened by heating, using a mold having a curved molding surface,
The glass plate is heated to the temperature required for molding while the glass plate not softened by heating is placed in advance on the molding surface of the mold not heated to the temperature required for molding. An apparatus for bending a glass plate, wherein the glass plate is formed into a curved shape following the forming surface by heating and softening.

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