JP2005170766A - Method and apparatus for bending glass plate - Google Patents

Abstract

The present invention provides a glass plate bending method and apparatus capable of producing a curved glass plate having a complicated bent shape from a flat glass plate produced by a float process or the like.
In a holding zone, a flat rectangular glass sheet G is held on a glass carrier 20 at room temperature. In the glass carrier 20, an opening 26 is formed at a portion corresponding to the molding region M in order to easily heat the molding region M of the glass plate G to a predetermined molding temperature while maintaining non-contact until molding. In the heating zone 14, the forming region M of the glass plate G is heated while being held by the glass carrier 20, and becomes a softened glass plate G having a viscosity of 10 ⁵ Pa · s to 10 ⁸ Pa · s. In the molding / trimming zone 16, the molding region M of the glass plate G descends toward the molding surface of the female mold 28 by its own weight, and molding is performed in contact with the molding surface. Detached from.
[Selection] Figure 1

Description

  The present invention relates to a glass plate bending method, and more particularly to a glass plate bending method for realizing a complicated bending shape.

  Recent window glass for buildings and automobiles is required to have various shapes and curvatures as the design changes. In particular, the rear glass for automobiles has a design that wraps deeply into the roof and both sides of the automobile, so that the amount of deformation is large and the amount of deformation is limited to a certain region, such as the longitudinal and transverse sections are bent. There is a demand for curved glass having a complicated bent shape.

  As one apparatus for producing curved glass, a press molding apparatus (for example, Patent Document 1) in a heating furnace is known. This press molding apparatus heats the glass plate to a temperature lower than the softening point (about 640 ° C.) during the roller conveyance of the glass plate in the roller hearth furnace, and after placing the glass plate on the press ring, the press ring and the male mold The glass plate is bent to a curved surface along the molding surface of the male mold.

  By the way, in the forming apparatus of Patent Document 1, since it is a forming apparatus using a roller hearth furnace that can only heat the glass plate to a temperature lower than the softening point, there is a limit to the shape that can be formed, and a deep bending shape curve that is bent. It is difficult to produce glass. When manufacturing such a glass plate, it may be formed by raising the molding temperature level in order to reduce the viscosity of the glass, that is, the glass plate may be heated to a temperature above the softening point. In the roller hearth furnace, the surface temperature can be easily scratched and distorted even by a small impact during the conveyance of the roller, and the quality of the glass plate itself is deteriorated, so the molding temperature level cannot be raised.

On the other hand, conventionally, a molding apparatus that manufactures curved glass tableware by pouring sheet-like molten glass directly into a female mold and pressing it with a plunger is known (for example, Patent Document 2). According to this shaping | molding apparatus, since the molten glass with low viscosity is used, the curved glass of the complicated bending shape along the shaping | molding surface of a female mold can be manufactured.
Japanese Patent Laid-Open No. 64-52628 JP 58-64226 A

  However, the forming apparatus of Patent Document 2 that directly bends molten glass has a problem in the surface quality of the manufactured curved glass plate due to its manufacturing method. For this reason, it cannot be applied as an automotive window glass molding apparatus that is required to have no optical distortion. That is, since window glass for automobiles is required to have no optical distortion, it is preferable to heat and form a flat glass plate having a fire-making surface manufactured by a float process. However, the conventional forming apparatus cannot form a curved glass plate having a complicated bent shape with a flat glass plate.

  This invention solves such a subject, and it aims at providing the bending method of a glass plate which can manufacture the curved glass plate of a complicated bending shape from a flat glass plate, and its apparatus. And

In order to achieve the above object, the present invention provides a female mold having a predetermined bend forming surface by converting a molding region of a glass plate heated to have a viscosity of 10 ⁵ Pa · s to 10 ⁸ Pa · s. A method of bending a glass sheet into a shape along the molding surface by pressing, wherein the glass sheet is controlled while controlling a molding temperature T and a molding time t so as to satisfy the following expressions (1) and (2): In the bending method of the glass plate for bending the plate, a glass holding member having a clamp member for clamping the edge of the glass plate and having an opening formed in a portion corresponding to the molding region of the glass plate is prepared, after holding the glass plate to the glass holding member, heating the molded region of the glass plate to the 10 ⁵ Pa · s or more 10 ⁸ Pa · s or less and made viscosity, the positioning member of the glass holding member The glass plate is positioned by pressing the molding area against the molding surface of the female mold through the opening of the glass holding member, and after the glass plate is bent, the glass plate is molded. Provided is a method for bending a glass plate, wherein the curved glass plate in the region is trimmed from the glass plate.

また、本発明は、前記目的を達成するために、粘度が１０⁵ Ｐａ・ｓ以上１０⁸ Ｐａ・ｓ以下となるように加熱されたガラス板の成形領域を、所定の曲げ成形面を有する雌モールドに押し付けることにより前記成形面に沿った形状に曲げ成形する装置であって、前記ガラス板の成形温度Ｔ及び成形時間ｔを、下記式（３）及び（４）を満足するように制御しながらガラス板を曲げ成形するガラス板の曲げ成形装置において、この装置の各部における動作の監視及び駆動を制御するコントローラを備え、このコントローラは、請求項１〜３の何れか一項に記載のステップをコンピュータに実現させるためのプログラムコードを記憶保持したことを特徴とするガラス板の曲げ成形装置を提供する。

In order to achieve the above-mentioned object, the present invention provides a molding region of a glass plate heated to have a viscosity of 10 ⁵ Pa · s or more and 10 ⁸ Pa · s or less, and a female having a predetermined bending molding surface. An apparatus for bending a glass plate into a shape along the molding surface by pressing the mold, wherein a molding temperature T and a molding time t of the glass plate are controlled so as to satisfy the following formulas (3) and (4). A glass sheet bending apparatus for bending a glass sheet while comprising a controller for controlling the monitoring and driving of the operation of each part of the apparatus, wherein the controller is a step according to any one of claims 1 to 3. A glass sheet bending apparatus characterized by storing a program code for causing a computer to realize the above-described method is provided.

湾曲ガラスの成形性拡大のためには、成形温度の高温化、すなわち、粘度を下げることが求められるが、ローラハース炉を用いた接触搬送方式の成形装置では、ローラ接触に起因するガラス板表面品質の劣化が避けられない。そのため、ガラス板の成形領域を成形時まで非接触を保ちつつ所定の成形温度まで加熱させるガラス保持部材が必要になる。また、成形時には、ガラス板の伸長量が極めて大きい条件となるため、ガラス板を安定して保持する機構も求められ、なおかつ、圧力成形を可能とする機構も求められる。また、成形終了後は、迅速に湾曲ガラス板を雌モールドから離型させる必要があり、接触による表面品質劣化を防止するためには、形状変化を最小限にとどめるための保持手段が求められる。

In order to increase the formability of curved glass, it is required to increase the molding temperature, that is, to reduce the viscosity. However, in the contact conveyance type molding apparatus using a roller hearth furnace, the surface quality of the glass plate caused by roller contact Degradation of is inevitable. Therefore, a glass holding member that heats the forming region of the glass plate to a predetermined forming temperature while maintaining non-contact until forming is necessary. Moreover, since the elongation amount of the glass plate is a very large condition at the time of forming, a mechanism for stably holding the glass plate is also required, and a mechanism that enables pressure forming is also required. Further, after the molding is completed, it is necessary to quickly release the curved glass plate from the female mold, and in order to prevent surface quality deterioration due to contact, a holding means for minimizing the shape change is required.

  Therefore, the present invention provides a glass holding member (Claims 1 and 6) provided with a forming auxiliary mechanism. That is, the glass holding member of the present invention includes a clamp mechanism that clamps the periphery of a flat glass plate in order to stably hold the glass plate. The flat glass plate is a rectangular glass plate manufactured by, for example, a float process and cut to have a larger area than a curved glass product. Since this glass plate has high flatness on both sides, it is suitable for an automotive window glass that is required to have no optical distortion.

  In view of attaching the glass plate to the glass holding member, the upper surface of the glass holding member is basically a flat surface, and an opening along the contour of the glass product having a desired shape is formed around the forming region. The opening has a role of preventing contact with the molding region of the glass plate until molding and a role of facilitating heating of the molding region until the temperature is increased to a predetermined molding temperature.

  The glass holding member is formed with a fitting portion to be fitted with the fitted portion of the fixed female mold and positioned with respect to the female mold (Claim 7), and the molding region of the glass plate is on the molding surface of the female mold. Opposed. Further, the gap between the formed connecting portions at the time of fitting is minimized as much as practically possible, and preferably a sealed space portion is formed by the forming region of the glass plate and the forming surface of the female mold. Thereby, this space part can be utilized as an air flow path on which vacuum / blow on the female mold side acts. Connection between the glass holding member and the female mold other than the molding surface is flat contact, and a sealing mechanism is provided so as to enable vacuum (Claim 3) / blow during molding. Further, the glass plate may be bent by pressing the softened forming region of the glass plate against the forming surface by its own weight (claim 2).

  After molding, in order to prevent deterioration of the glass plate surface quality, it is necessary to quickly release from the female mold. As a mechanism for minimizing the shape change, the glass plate (curved glass plate) in the molding area Only the edge portion is held by the glass holding member. Moreover, the trimming which cuts out a curved glass plate from a glass plate is implemented with a cutter immediately before isolate | separating a glass holding member from a female mold. At this time, in order to facilitate cutting by the cutter, it is preferable to form a groove on the glass holding member side for the cutter that cuts the curved glass plate to dig in. Moreover, the taper surface which the said edge part contacts is formed in the edge part of the opening part of a glass holding member so that only the edge part of a curved glass plate may be hold | maintained to a glass holding member.

By the way, in the present invention, the molding surface is formed by pressing a molding region of a glass plate heated so that the viscosity is 10 ⁵ Pa · s or more and 10 ⁸ Pa · s or less against a female mold having a predetermined bending molding surface. Bending and forming the glass plate while controlling the forming temperature T and the forming time t of the glass plate so as to satisfy the above formulas (1) and (2). It assumes a glass plate bending method and apparatus.

  Here, the principle of the present invention will be described. The present inventor has found through experiments or simulations that in order to realize a complicated bending shape, it is necessary to satisfy two types of factors of formability and releasability. For example, in order to realize a complicated bending shape including at least one portion having a radius of curvature of 100 mm or less, it is necessary to lower the viscosity by heating the glass plate to a higher temperature than before, but the viscosity is extremely reduced. When lowered, the glass plate is fused to the molding surface of the female mold during bending. Therefore, the present inventors proposed a molding evaluation index φ shown in the formula (1) in Japanese Patent Application No. 2002-299423, and the molding time and the time are set so that the index satisfies the predetermined range shown in the formula (2). It was confirmed that by controlling the molding temperature, sufficient bend formability and releasability were obtained.

First, the process of deriving the molding evaluation index φ will be described. Glass is a substance whose physical properties change with changes in temperature. From the low temperature side, elasticity (η> 10 ^13.5 (Pa · s)), viscoelasticity (10 ^8.0 <η <10 ^13.5 (Pa · s)), viscosity ( The physical properties η <10 ^8.0 (Pa · s)) are sequentially shown. These numerical ranges vary slightly depending on the glass composition.

  Conventional bending techniques are carried out in the viscoelastic temperature range (about 640 ° C.). Specifically, bending is performed by applying a bending force from the outside using a male mold. The principal mechanism is that a bending stress based on elastic mechanics and a stress relaxation phenomenon peculiar to a viscoelastic body proceed simultaneously in parallel to finally obtain a predetermined shape in which no springback occurs. Therefore, cracks may occur when the stress generated during molding exceeds a certain threshold value, and the expansion / contraction rate distribution from the flat plate regarding the shape after molding may rarely exceed 1% locally, but within 1%. It is normal.

On the other hand, the molding shape targeted by the present invention cannot be achieved with an expansion / contraction ratio of 1% or less, and cannot be solved by the above-described conventional technology. Therefore, in the present invention, it is necessary to lower the viscosity of the glass plate (10 ⁵ Pa · s or more and 10 ⁸ Pa · s or less) as compared with the conventional case, and to mainly mold using viscous flow. Under these conditions, the elastic effect is almost ignored and the viscosity law becomes dominant. Therefore, in order to perform bending under such circumstances, the physical phenomena related to bending are organized by the three parameters of viscosity, pressure, and action time.

  Therefore, in the present invention, the conventional bending forming is performed by using the above-described forming evaluation index φ in which the relationship between these three parameters is made dimensionless, and performing bending forming so that the index φ is within a predetermined numerical range. Eliminate various problems that sometimes occurred. Further, even if the parameters are different molding conditions, it means that the same molded shape can be expected if the index φ is the same value, and the molding conditions can be set as appropriate.

  FIG. 12 is a graph showing the relationship between the forming evaluation index φ and the surface pressure holding time t of the glass plate. As shown in the figure, it can be seen that the value of the index φ increases with the elapse of time t. φ is a dimensionless number, and represents that the range shown in Formula (1) is a formable region. The figure shows the case where the surface pressure difference is constant and the case where the viscosity is constant, but the essence of the principle is as long as the calculated value of Equation (2) satisfies Equation (1) regardless of which parameter is a variable. Are equivalent.

  Here, sufficient bend formability means that the glass plate comes into contact with the entire range of the molding surface corresponding to the roughly predetermined shape of the female mold at the time of molding. It shows that the surface of the plate can be peeled off from the female mold without fusing, and it is defined that molding is possible under conditions where these two states are compatible. That is, when the molding evaluation index φ is less than 0.05, there is a possibility that a portion where the glass is not in contact may occur in the range of the molding surface corresponding to the roughly predetermined shape of the female mold. If it exceeds 00, the glass may be fused to the female mold after molding and may not be peeled off from the female mold. If a hole such as vacuum suction exists, that portion is not included in the contact determination range.

  Further, the surface pressure difference P is not necessarily a narrowly defined pressure, and includes a concept of converting the surface pressure to an equivalent surface pressure when a load such as its own weight is received. That is, in the case where press molding is used in combination, a pressure value equivalent to the load is added as a component of the surface pressure difference P for a portion to which a press load is applied. In this way, in the situation where the surface pressure difference P or the viscosity varies depending on the part, it can be easily imagined that the value of the molding evaluation index φ also varies depending on the part. In this case, the molding evaluation index φ is approximately predetermined. The highest value in the shape range is adopted, and it is determined by the equation (1).

  As described above, the molding method according to the present invention and the molding method according to Patent Document 1 have a large difference in the molding concept in the first place. For comparison, if the molding method according to the prior art is evaluated with the molding evaluation index φ, the formula As shown in (5), it can be seen that the numerical range of the expression (1) is greatly deviated.

According to the glass plate bending method and the apparatus according to the present invention, the glass holding member having the clamp member for clamping the edge of the glass plate and having an opening formed in a portion corresponding to the forming region of the glass plate. After preparing and holding a glass plate on the glass holding member, the glass plate forming region is heated to a viscosity of 10 ⁵ Pa · s to 10 ⁸ Pa · s, and the glass holding member is Positioned on the mold and bent by pressing the molding region against the molding surface of the female mold through the opening of the glass holding member. After bending the glass plate, the curved glass plate in the molding region of the glass plate Therefore, it is possible to manufacture a curved glass plate having a complicated bent shape from a flat glass plate.

  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.

  FIG. 1 is a side view schematically showing a glass sheet bending apparatus 10 according to the embodiment, and FIG. 2 is a plan view of the bending apparatus 10 shown in FIG. As shown in FIG. 1, the bending apparatus 10 includes a holding zone 12, a heating zone 14, a forming / trimming zone 16, an unloading zone 18, and the like from the upstream side of the glass forming process. The transfer is performed by a transfer device (not shown).

  The holding zone 12 is a zone for holding the flat rectangular glass plate G on the glass carrier (glass holding member) 20 shown in FIG. 3 at room temperature, and this holding is performed by a robot (not shown). After the glass carrier 20 is placed on the gantry 22 shown in FIG. 1, the glass plate G is placed on the flat upper surface thereof.

  As shown in FIG. 3, clamp plates 24, 24... (Clamp mechanism) that hold the four edges of the glass plate G are attached to the glass carrier 20, and the clamp plates 24, 24. By fastening to the glass carrier 20, the glass plate G is held between the glass carrier 20 and the clamp plates 24, 24. By firmly holding the glass plate G in this way, the glass plate G can be stably held on the glass carrier 20 at the time of molding where the elongation amount of the glass plate G is extremely large.

  Further, in order to easily heat the glass carrier 20 to the predetermined molding temperature while keeping the molding area M indicated by the broken line of the glass plate G in the non-contact state until molding, a portion corresponding to the molding area M is shown in FIG. An opening 26 is formed as described above. Further, on the lower surface side of the periphery of the opening 26, there is a fitting portion 30 to be fitted with a fitting portion (not shown) of the female mold 28 of the molding / trimming zone 16 shown in FIG. Protrusions are formed. A plurality of ribs 32 and 32 are formed on the lower surface of the glass carrier 20, and the glass carrier 20 is reinforced by the ribs 32. Examples of the glass carrier 20 include ceramics excellent in heat resistance or metals such as iron.

  Further, positioning sockets 31, 31... Projecting upward are attached to the four corners of the glass carrier 20, and concave portions 31A are formed on the upper surface of the positioning socket 31. The positioning socket 31 will be described later. Further, glass carrier shuttle guide protrusion fitting guide holes 33A and 33A are respectively formed in the center of the upper and lower sides of the glass carrier 20 in FIG. In addition, guide holes 33B and 33B for fitting the conveyance chain guide protrusions are formed inside the guide holes 33A and 33A. These guide holes 33A and 33B will also be described later.

In FIG. 1, the glass carrier 20 holding the glass plate G is placed on the frame 36 of the heating zone 14 with the door 34 opened. The heating zone 14 is a heating furnace in which electric heaters 38, 38... Are installed on the ceiling surface, floor surface, and side surfaces. In the heating zone 14, the glass plate G is heated to, for example, 670 to 830 ° C. while being held by the glass carrier 20, and here the softened glass plate having a viscosity of 10 ⁵ Pa · s to 10 ⁸ Pa · s. G. In addition, you may forcibly heat the shaping | molding area | region M of the glass plate G not only with the electric heater 38 but with a gas burner. Further, after the glass plate G is heated by a separately provided heating device so that the viscosity becomes 10 ⁷ Pa · s (temperature: about 710 ° C.) or more, the glass plate G is held on the glass carrier 20, and then The heating zone 14 may be heated to 714 ° C to 830 ° C.

  The glass plate G heated to the viscosity is conveyed to the molding / trimming zone 16 after the door 40 is opened while being held by the glass carrier 20. Then, by fitting the fitting part 30 of the glass carrier 20 into the fitting part of the female mold 28, the molding region M is positioned on the complicated bending-shaped molding surface of the female mold 28. Even during molding, heating is continued by a heater (not shown) installed in the molding / trimming zone 16, whereby the molding region M of the glass sheet G descends toward the molding surface of the female mold 28 by its own weight. Then, the molding is performed in contact with the molding surface. A molding space is formed by the molding region M and the molding surface, and the molding region M is forcibly brought into close contact with the molding surface by vacuuming the air in the sealing space with a suction device connected to the female mold 28. You may make it shape | mold. The molding condition is a condition where the molding evaluation index φ satisfies the formula (1). Further, the vacuum pressure, the molding temperature, and the molding time are adjusted by a controller (not shown) so as to follow the equation (2). In order to shorten the molding time, it is desirable that the surface pressure difference is large.

  The glass plate G that has been molded is separated from the glass plate G by a cutter 42 installed in the molding / trimming zone 16 from a molding region (hereinafter referred to as a curved glass plate) M. The cutter 42 is formed in a shape along the peripheral edge (contour) of the curved glass plate M, and is attached to the lower portion of the header 44, and the header 44 is attached to the piston 48 of the hydraulic cylinder 46. Therefore, the header 44 is moved downward by the extension operation of the piston 48, and the curved glass plate M is separated by the cutter 42. Note that a positioning protrusion (not shown) that fits into the recess 31A of the positioning socket 31 of the glass carrier 20 shown in FIG. 3 is provided on the lower surface of the header 44. Prior to cutting by the cutter 42, it fits into the recess 31 </ b> A of the positioning socket 31. Thereby, the cutter 42 and the glass carrier 20 are relatively positioned, and the cutting by the cutter 42 is accurately performed by the downward movement of the header 44.

  The separated curved glass plate M is supported by the tapered surface 26A of the opening 26 of the glass carrier 20 shown in FIG. After the door 40 is opened in this state, it is transported to the carry-out zone 18. Then, the glass carrier 20 is conveyed from the carry-out zone 18 to an unillustrated air-cooling strengthening device, where after the air-cooling strengthening, the curved glass plate M is taken out from the glass plate G, and the curved glass plate M is packed. Alternatively, the glass carrier 20 is returned to the holding zone 12 in the inspection process and after the unnecessary glass plate G is removed.

  As described above, the glass plate bending apparatus 10 according to the embodiment holds the glass plate G on the glass carrier 20 so that the forming region M of the glass plate G is not contacted until the forming / trimming zone 16 is formed. Since it was possible to heat to a high temperature forming temperature equal to or higher than the softening point while maintaining, a curved glass plate M having a complicated bent shape can be manufactured from the flat glass plate G.

  FIG. 5 is a side view schematically showing the structure of an automobile rear glass bending apparatus 100 according to the embodiment, and FIG. 6 is a plan view schematically showing the structure of the bending apparatus 100 shown in FIG. is there.

  As shown in FIG. 6, the bending apparatus 100 has a configuration in which the glass carrier 20 shown in FIG. 3 circulates between a plurality of zones, and includes a plate loading zone 102, a glass carrier transfer device 104, a transport chain 106, 108 (two-way), heating zone 110, glass carrier transport shuttle 112, molding / trimming zone 114, pickup zone 116, air-cooling strengthening zone 118, glass carrier drawing device 120, and cullet chute 122 circulate around glass carrier 20. Arranged in order of direction. In addition, the operation timing, the heater temperature, and the like of these units are comprehensively controlled by the controller 124.

  In the plate loading zone 102, a flat glass plate G is placed on the glass carrier 20 by a robot (not shown), and is clamped and held.

  The glass carrier 20 on which the glass plate G is clamped is transported to a specified position near the end of the transport chain 106, and is then moved by four thrusting devices (for example, air cylinder devices) 126, 126. The pair of forks 128, 128 of the glass carrier transfer device 104 that has risen with the four corners being supported and retracted to the side of the glass carrier 20 are inserted into the lower part of the glass carrier 20. As the push-up devices 126, 126... Are lowered, the glass carrier 20 is placed on the pair of forks 128, 128 of the glass carrier transfer device 104, and is conveyed above the start end of the conveyance chain 108 by the operation of the forks 128, 128. Is done.

  Four thrusting devices (for example, an air cylinder device: only two thrusting devices are shown in FIG. 5) 130, 130... Are arranged on the start end side of the transport chain 108, and the four thrusting devices 130, The glass carrier 20 is raised again by the upward movement of 130. Then, after the forks 128, 128 are retracted to the transport chain 106 side, the glass carrier 20 is placed on the transport chain 108 by the downward movement of the four thrusting devices 130, 130 and set at the entrance of the heating zone 110. The A guide projection (not shown) is provided on the upper portion of the conveyance chain 108, and guide holes 33B and 33B (see FIG. 3) of the glass carrier 20 are fitted into the projection, and the positional deviation due to slippage during the conveyance of the glass carrier 20 is fitted. Is prevented.

  The heating zone 110 uses an electric heating furnace as a main heating source, but a convection heating device may be used in an auxiliary manner. A continuous space as shown in FIGS. 5 and 6 may be used, or the space may be divided into a plurality of zones separated by doors. These electric heating furnaces are provided with a ceiling heater, a floor heater, and a side heater. In addition, illustration of a heater is abbreviate | omitted for convenience of explanation. In each heater, the temperature applied to the glass plate is set for each installation location according to the size, thickness, and the like of the glass plate to be bent.

The glass plate G is transported in the electric heating furnace by the transport chain 108, and the molding region M of the glass plate G is heated to, for example, about 670 to 830 ° C., where the viscosity is 10 ⁵ pa · S or more and 10 ⁸ Pa. -It becomes the softened glass plate below s. Since the glass carrier 20 has an opening along the contour of the glass product having a desired shape, radiation heating from the upper and lower surfaces by the heater is easy, and the glass surface quality is deteriorated by contact with the glass carrier 20. Can be prevented. When the temperature of the glass plate G is in the vicinity of the softening point (for example, 730 ° C.), the glass plate G bends by its own weight, but because the glass carrier 20 is firmly clamped around the glass plate G, it does not slide down. There is no problem in molding. Further, after the glass plate G is heated by a separately provided heating device so that the viscosity becomes 10 ⁷ Pa · s (temperature: about 714 ° C.) or higher, the glass plate G is held on the glass carrier 20, and then The heating zone 110 may be heated to 710 ° C to 830 ° C.

  The glass carrier 20 that holds the forming region M of the glass sheet G that has reached the predetermined forming temperature is lifted off the transport chain 108 by the rising of the support beams 132 and 132 of the glass carrier transport shuttle 112 that is waiting at the bottom. To do. Similarly to the transport chain 108, guide protrusions (not shown) are also provided on the support beams 132 and 132, and guide holes 33A and 33A (see FIG. 3) of the glass carrier 20 are fitted into the protrusions. In addition, displacement due to slippage during the conveyance of the glass carrier 20 is prevented.

  The glass carrier 20 placed on the glass carrier transport shuttle 112 is transported to the molding / trimming zone 114 after the door 134 is opened. The glass carrier transport shuttle 112 is configured to reciprocate the rear end portion of the heating zone 110, the molding / trimming zone 114, and the pickup zone 116 by transport means such as a timing belt driving device 136, and moves as shown in FIG. An opening 138 is formed in the hearth of the range so as to be movable.

FIG. 7 shows a partial cross-sectional view of the state of being conveyed to the molding / trimming zone 114. A plurality of through holes 140, 140... Are formed on the molding surface 29 of the female mold 28 (the surface in contact with the glass plate G). These through holes 140, 140... Communicate with a pressure chamber 142 formed on the lower surface of the female mold 28. The pressure chamber 142 is connected to a cylinder 146 filled with an inert gas such as N ₂ (nitrogen) gas through a duct 144, and the inert gas is adjusted to an appropriate pressure by a control valve 148. After that, the pressure chamber 142 is supplied to the pressure chamber 142 through the duct 144 and supplied into the molding / trimming zone 114 through the through holes 140, 140. In the case where the female mold 28 is made of metal, it is desirable to always supply the inert gas at an appropriate pressure other than during molding in order to prevent oxidation of the molding surface 29. This is because when the rust is generated by the oxidation of the molding surface 29, the molding region M of the bent glass sheet G is easily fused to the molding surface 29, and the releasability of the curved glass sheet is deteriorated. Since the molding / trimming zone 114 is separated by the front and rear zones (heating zone 110 and pickup zone 116) and doors 134, 150 as shown in FIG. The whole can be under a substantially inert gas atmosphere.

  Next, by lowering the support beams 132 and 132 of the glass carrier transport shuttle 112, the glass carrier 20 is moved downward toward the female mold 28, and the fitting portion 30 of the glass carrier 20 is fitted to the fitting portion of the female mold. To fit. As a result, the glass carrier 20 is placed at a predetermined position of the female mold 28 as shown in FIG. The lower surface around the molding region M of the glass carrier 20 is in plane contact with the upper flat region outside the molding region of the female mold 28 and sealed, and the space surrounded by the molding region M and the molding surface 29 penetrates the pressure chamber 142. It becomes the sealed space 152 communicated through the holes 140, 140... (See FIG. 8). The clearance between the molding region connecting portion of the glass carrier 20 and the female mold 28 at the time of fitting may be as small as possible within a practical range, and may be an air flow path for acting vacuum / blow from the female mold 28 side. . When the sealed space 152 is formed, the glass sheet G can be expanded in the direction opposite to the molding direction as shown in FIG. 8 by increasing the supply pressure of the inert gas. Performing such an operation has the effect of reducing the thickness deviation after molding. At that time, in order to prevent the glass carrier 20 from being lifted, a pressing jig (not shown) is used.

  As shown in FIG. 7, a vacuum tank 156 is connected to the pressure chamber 142 via a duct 154. When the control valve 158 is opened, the air in the sealed space 152 is vacuumed through the duct 154, the pressure chamber 142, and the through holes 140, 140. As a result, the sealed space 152 becomes negative, and the molding area M of the glass sheet G is sucked toward the molding surface 29 as shown in FIG. By this suction operation, the molding region M is bent and formed into a complicated bent surface along the molding surface 29. The molding condition is a condition in which the molding evaluation index Φ satisfies the formula (1), and the vacuum pressure, the molding temperature, and the molding time are adjusted by the controller 124 so as to follow the formula (2).

  A molding region (hereinafter, curved glass plate) M of the glass plate G bent by the female mold 28 is cut by the cutter 42 by the downward movement of the header 44 as shown in FIG. 10 and separated from the surrounding glass plate G. At this time, the cutter 42 and the glass carrier 20 are relatively positioned by the attachment determining mechanism, and the amount of biting of the cutter 42 can be controlled. That is, as shown in FIG. 10, a positioning guide pin 45 is provided on the lower surface of the header 44 at a position facing the positioning socket 31 of the glass carrier 20, and the tip protrusion 45A of the positioning guide pin 45 is moved when the header 44 is moved downward. However, prior to cutting by the cutter 42, it fits into the recess 31 </ b> A of the positioning socket 31. Thereby, the cutter 42 and the glass carrier 20 are relatively positioned, and the cutting by the cutter 42 is accurately performed by the downward movement of the header 44.

  In order to facilitate cutting, a groove 160 that allows the cutting edge of the cutter 42 to escape can be formed on the tapered surface 26A of the opening 26 of the glass carrier 20 along the cutting portion as shown in FIG. Note that the surface temperature of the female mold 28 and the temperature of the cutter 42 are not necessarily equal to the glass molding temperature, and may be lower than the glass molding temperature. In that case, there is an effect that the releasability after molding is improved.

  As described above, according to the technique using the present invention, the curved glass plate M having a complicated bent shape including the peripheral part is obtained for the first time by the trimming operation. There exists an advantage which can avoid the shaping | molding shape dispersion | variation accompanying such a mounting position shift | offset | difference of a glass plate. In addition, if an oversized flat glass plate G can be prepared, an accurate positioning operation of the glass plate G is not necessary, and the glass plate G having a shape developed into a flat shape so as to have a predetermined bent shape is used as a pre-process. There is also an advantage that the cutting work prepared in step 1 and the chamfering work for the purpose of improving the strength of the peripheral edge become unnecessary.

  Since the peripheral portion of the cut curved glass plate M is placed on the tapered surface 26A formed in the opening 26 of the glass carrier 20, the glass carrier transport shuttle shown in FIG. The curved glass plate M and the female mold 28 are immediately separated by raising the support beams 132, 132, and the door 150 is opened, and then conveyed to the pickup zone 116.

  When transported to the big-up zone 116, the support beams 132 and 132 of the glass carrier transport shuttle 112 are lowered and the glass carrier 20 is placed on the stand 162. Thereafter, the glass carrier transport shuttle 112 retreats to the molding / trimming zone 114, and at the same time, the vacuum head 164 descends from the top, picks up the curved glass plate M with a light vacuum pressure that does not deteriorate the surface quality, and lifts and retreats. To do.

  The side door 166 is opened, and the pair of forks 168 and 168 of the glass carrier drawing device 120 shown in FIG. 6 enters the furnace, and receives and conveys the glass carrier 20 with the surrounding glass plates remaining. Then, it is retracted onto the transport chain 106. A push-up device (not shown) is installed at a specified position of the transport chain 106. After the glass carrier 20 is raised by the push-up device, the forks 168 and 168 of the glass carrier pull-out device 120 are glass carriers. It is retracted to the side 20 and set on the transport chain 106 by the lowering of the thrusting device. A guide protrusion (not shown) is provided on the upper portion of the transport chain 106, as in the case of the transport chain 108, and guide holes 33B and 33B (see FIG. 3) of the glass carrier 20 are fitted into the protrusion. Misalignment due to slippage during transport is prevented.

  After the glass carrier 20 is retracted from the pickup zone 116, the rear end side door 170 is opened, and the quench ring 172 enters the pickup zone 116. When the quench ring 172 stops at the specified position, the vacuum head 164 retracted to the upper part is lowered, the vacuum pressure is released, and the curved glass plate M is placed on the quench ring 172.

  The curved glass plate M is conveyed to the air-cooled tempering zone 118 by the quench ring 172, and is tempered by a known method to obtain tempered glass having a predetermined complicated bending shape.

  The glass carrier 20 in which the surrounding glass is left is conveyed to the cullet chute 122 shown in FIG. 6 by the conveying chain 106, and after the clamp holding is released, the surrounding glass falls on the cullet chute 122. The glass carrier 20 from which unnecessary glass has been removed is transported to the plate mounting zone 102 by the transport chain 106, and a new flat glass plate G is set for use in the next molding cycle.

  According to the glass sheet bending apparatus configured as described above, the plurality of glass carriers 20 on which the flat glass sheets G are clamped and held are heated in a heating furnace, and the expression (1) and Since the molding region is bent under the condition satisfying the formula (2), the positional deviation is offset from the oversized flat glass slope G in which the cutting step and the chamfering step according to the shape in the previous step are omitted. Without concern, it is possible to manufacture a rear glass for automobiles having a complicated bent shape. Moreover, according to this bending molding apparatus, since bending molding is fully automated, it is suitable for mass production.

  Further, it is obvious that the present invention can be applied not only to molding various glass plates (rear glass, door glass, windshield) and the like for automobiles but also to molding glass plates for railway vehicles, aircraft, ships or buildings. .

The side view which showed the structure of the bending apparatus of the glass plate of this Embodiment Top view of the bending apparatus shown in FIG. The top view which shows the state by which the glass plate was hold | maintained at the glass carrier Cross section of the glass carrier as seen from line 4-4 on FIG. Side view schematically showing the structure of the bending apparatus according to the present embodiment The top view which showed typically the structure of the bending apparatus shown in FIG. Explanatory drawing including a partial cross-section showing a state where the glass carrier is conveyed and placed in the molding / trimming zone Explanatory drawing including the partial cross section which showed the state by which the glass carrier was mounted in the female mold and the glass plate hold | maintained at the glass carrier was expanded. Explanatory drawing including the partial cross section which showed the state by which the shaping | molding area | region of the glass plate was closely_contact | adhered and shape | molded to the female mold Explanatory drawing including the partial cross section which showed the state by which the curved glass plate was cut away with the cutter of a shaping | molding / trimming apparatus Sectional drawing which expanded and showed the cutting part of the curved glass plate shown in FIG. (A) A graph showing the relationship between the forming evaluation index and the bending time when the surface pressure difference is constant, (b) A graph showing the relationship between the forming evaluation index and the bending time when the viscosity is constant

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10,100 ... Bending apparatus of a glass plate, 12 ... Holding zone, 14 ... Heating zone, 16 ... Molding / trimming zone, 18 ... Unloading zone, 20 ... Glass carrier, 24 ... Clamp plate, 26 ... Opening, 28 ... Female mold, 30 ... mating part, 32 ... rib, 38 ... electric heater, 42 ... cutter, 102 ... plate mounting zone, 104 glass carrier transfer device, 106, 108 ... transport chain, 110 ... heating zone, 112 ... glass carrier Transport shuttle, 114 ... Molding / trimming zone, 116 ... Pickup zone, 118 ... Air-cooling strengthening zone, 120 ... Glass carrier drawing device, 122 ... Callet chute, 124 ... Controller, 126, 130 ... Push-up device

Claims (7)

A glass plate that is heated to have a viscosity of 10 ⁵ Pa · s or more and 10 ⁸ Pa · s or less is pressed into a female mold having a predetermined bending surface to bend the shape along the forming surface. In a method for forming a glass plate, the glass plate is bent while controlling a forming temperature T and a forming time t of the glass plate so as to satisfy the following formulas (1) and (2). ,
A glass holding member having a clamp member for clamping the edge of the glass plate and having an opening formed in a portion corresponding to a molding region of the glass plate is prepared,
After holding the glass plate on the glass holding member, the molding region of the glass plate is heated to a viscosity of 10 ⁵ Pa · s to 10 ⁸ Pa · s,
Position the glass holding member on the female mold via the positioning member,
Bending by pressing the molding region against the molding surface of the female mold through the opening of the glass holding member,
A method for bending a glass plate, comprising: trimming a curved glass plate in a forming region of the glass plate from the glass plate after the glass plate is bent.

  The glass plate bending method according to claim 1, wherein the glass plate forming region is bent by its own weight.   The glass plate bending method according to claim 1, wherein the glass plate forming region is vacuum-bent to the forming surface side of the female mold and bent.   The said glass plate is a glass plate manufactured by the float glass process, The bending forming method of the glass plate as described in any one of Claims 1-3.   The said glass plate is a bending method of the glass plate as described in any one of Claims 1-4 used for the window glass of a motor vehicle. A glass plate that has been heated so that its viscosity is 10 ⁵ Pa · s or more and 10 ⁸ Pa · s or less is pressed into a female mold having a predetermined bending surface to bend the shape along the forming surface. An apparatus for forming a glass plate, wherein the glass plate is bent while controlling the forming temperature T and the forming time t of the glass plate so as to satisfy the following formulas (3) and (4): ,
A controller for controlling monitoring and driving of each part of the apparatus is provided, and the controller stores and holds a program code for causing a computer to execute the steps according to any one of claims 1 to 3. Characteristic glass plate bending apparatus.

  The fitting portion for positioning the glass holding member with respect to the female mold is formed by fitting the glass holding member to the fitted portion of the female mold. Glass plate bending equipment.

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