JP5046075B2 - Glass article molding method and molding apparatus - Google Patents

Description

  The present invention relates to a method and apparatus for molding a glass article. More specifically, the present invention relates to a glass material placed on a molding die having one or a plurality of molding recesses, and one or more using a suction force due to negative pressure. The present invention relates to a method and an apparatus for forming a glass article having a concave portion.

  In recent years, as a method for producing a glass article having one or a plurality of recesses such as a glass container or a cover glass for an image sensor or a glass for a liquid crystal backlight, a glass material made of a flat glass plate is heated. Thus, a method of softening and deforming and solidifying while conforming to a molding concave portion of a mold by a negative pressure has been adopted.

  As an example, according to Patent Document 1 below, for example, a molding die having a molding surface with an uneven upper surface and a large number of through holes (ventilation holes) is fixed to the bottom of a heating furnace (electric furnace chamber). In addition, a technique is disclosed in which a plate glass is placed on the mold and heated, and a negative pressure is applied to the molding surface through a through hole to form the plate glass into a shape that follows the irregularities of the molding surface.

  In this case, the large number of through holes formed in the mold are joined at the counterbore formed at the bottom of the mold and on the bottom wall of the heating furnace, and the counterbore is connected to the rotary pump. It is connected to a connected suction tube. Accordingly, when the rotary pump is operated, a negative pressure is generated in the counterbore portion through the suction pipe, and this negative pressure acts on the molding surface of the mold through a large number of through holes.

  According to FIG. 6 of Patent Document 2, a plate glass heated to a softening point or higher is placed on a mold having a recess formed on the contact surface with the plate glass, and the space surrounded by the plate glass and the recess is evacuated. It is disclosed that immediately after forming a glass sheet by drawing and sucking the glass sheet into a recess of the mold, an attachment hole for attaching an electrode is provided, and this glass sheet is placed in a furnace and gradually cooled.

  In this case, a plurality of through holes that lead to the plurality of recesses are formed in the mold, and these through holes merge in the internal space of the cover that covers the back surface of the mold, and the internal space of the cover is It is connected to a rotary pump through piping and valves. Therefore, the plate glass is evacuated to the shape of the molding surface of the mold by sucking the air in the inner space of the cover through a valve and piping by a rotary pump and drawing the inside of the mold recess through a through hole. Molded.

JP-A-4-275930 JP-A-11-204035 (FIG. 6)

  By the way, according to the sheet glass forming apparatus disclosed in Patent Document 1, the bottom surface of the forming die covers the entire upper end opening of the counterbore part where a large number of through-holes merge. The bore is in a state of being cut off from the internal space of the heating furnace. In detail, under the state where the plate glass is placed on the mold, the entire space from the forming space surrounded by the concave portion of the forming surface and the back surface of the plate glass to the counterbore portion through the many through holes is heated. It is in a state of being completely cut off from the interior space of the furnace.

  For this reason, even if the internal space of the heating furnace is in a high temperature state sufficient to soften the plate glass, the temperature of the counterbore part is maintained at a relatively low state, and therefore, the counterbore part communicates with the counterbore through the through hole. The forming space on the back side of the plate glass is also maintained at a relatively low temperature. As described above, when the space on the front side of the softened glass sheet is heated to a high temperature, if the molding space on the back surface side of the glass sheet is low in temperature, negative pressure is still generated in the molding space. Even if there is no stage, due to the pressure difference between the two spaces, the glass plate is deformed to be bent toward the forming space.

  In this case, if a special glass is excluded, the plate glass has a characteristic of transmitting a large amount of heat rays. Therefore, in the method of heating the plate glass on the mold as described above, in the heating process, The mold tends to be heated earlier than the plate glass. Therefore, the plate glass is supplied with heat from the mold and reaches the softening temperature. In view of such a phenomenon, the plate glass first reaches the softened state of the contact portion with the mold, whereas the non-contact portion with the mold cannot yet reach the softened state. Causes a situation in which a softened part and a non-soft part are mixed.

  And, when the dent deformation resulting from the pressure difference between the two spaces occurs in the plate glass softened in a non-uniform manner in this way, only the softened part is extremely deformed and finally In addition to being an adverse effect in obtaining the original target shape, unreasonable elongation occurs only in the softened part, and it is extremely difficult to obtain a uniform thickness distribution. For such a problem, it is conceivable to make the softened state of the plate glass uniform by slowing the heating rate (temperature increase rate). However, with such a simple method, the productivity is significantly reduced. In addition to causing a fatal problem, an additional deformation that adversely affects the final shape may still occur in combination with the occurrence of a depression deformation due to the weight of the plate glass.

  Further, according to the molding method disclosed in Patent Document 2, a plate glass heated to a temperature higher than the softening point (approximately 900 ° C.) is placed on a mold heated to about 500 ° C. Since the inside of the concave portion of the plate is evacuated, when the plate glass is placed on the mold, the contact portion with the plate glass mold becomes low temperature, whereas the non-contact portion is maintained at high temperature. . Therefore, in this case as well, the probability of occurrence of defects due to depression deformation due to the weight of the plate glass is increased, and the degree of softening of the plate glass is different between the vicinity of the contact portion and the vicinity of the non-contact portion. , Wall thickness distribution is non-uniform.

  Moreover, in this molding method, since the molding process of placing the plate glass on the mold and evacuating is not performed in a furnace such as a heating furnace, the surface of the sheet glass is in the stage before evacuation at the time of molding. Appropriate temperature control is not performed for the side space and the space surrounded by the concave portion on the back surface side. For this reason, there is a possibility that an unreasonable air pressure difference may occur between the two spaces, and this air pressure difference also increases the probability that the dent deformation occurs in the plate glass having the non-uniform degree of softening as described above. As in the case, it is extremely difficult to obtain an even thickness distribution.

  The present invention has been made in view of the above circumstances, and in forming a target shape by applying a negative pressure in a state where a glass material such as plate glass is heated and softened, the glass is formed in a stage before applying the negative pressure. An object of the present invention is to form a glass article having a uniform wall thickness distribution while avoiding undue deformation of the manufactured material.

The method according to the present invention has been made to solve the above SL technical problem, the interior space of the heating furnace, a mold and the vent hole is formed leading to the inside of one or more shaped recesses and the shaped recesses In a state where the glass material is placed on the mold so as to cover the molding recess, a negative pressure is applied to the molding space surrounded by the molding recess and the back surface of the glass material through the vent hole. In the method of forming a glass article in which one or a plurality of recesses are formed by acting, a chamber that communicates with the vent hole at the bottom of the mold and covers the entire or substantially entire area of the bottom surface of the mold from below. And after placing a part or all of the chamber in the internal space of the heating furnace and heating the internal space of the heating furnace and the internal space of the chamber, a negative pressure is applied to the internal space of the chamber. Characterized in that to produce.

According to such a configuration, the chamber that is attached to the bottom of the mold and communicates with the molding space via the vent hole is partially or entirely located inside the heating furnace. It is heated by the hot air in the heating furnace. Therefore, the temperature of the internal space of the chamber can be equivalent to the temperature of the internal space of the heating furnace, that is, the temperature of the surface side space of the glass material. As a result, the temperature difference between the molding space on the back side of the glass material that communicates with the internal space of the chamber and the space on the front surface side of the glass material becomes extremely small. Get smaller. As a result, in the process of heating the glass material placed on the mold so as to cover the molding recess in the internal space of the heating furnace (the process until suction by negative pressure is started), the glass Unjust dent deformation resulting from the above-mentioned pressure difference is less likely to occur in the manufactured material. In other words, it is difficult for unjust dent deformation to occur until the softened state of the glass material is appropriately uniformed over the entire area. In Thereafter, that obtained glass article and thickness distribution close to the ideal shape of the final object are equalized (by generating negative pressure in the internal space of the chamber in this case) by the action of negative pressure .

  In this case, it is preferable that the communication path that communicates with the internal space so as to generate a negative pressure in the internal space of the chamber can be opened and closed.

  In this way, if the communication path leading to the internal space of the chamber is closed by valve means such as an open / close valve between the start of heating of the glass material and the start of suction by negative pressure, the interior of the chamber Since the hot air in the space can be surely prevented from escaping to the outside and the atmospheric pressure in the chamber internal space can also be prevented from escaping, it is advantageous in maintaining the temperature and pressure in the internal space of the chamber at the above-described appropriate values.

  Further, it is preferable that the entire chamber is located in the internal space of the heating furnace, and the bottom surface of the chamber is separated from the bottom surface of the heating furnace.

  In this way, the surface area of the chamber exposed to the hot air in the internal space of the heating furnace is increased, and the heating efficiency for the internal space of the chamber is increased, so that the back surface of the glass material that communicates with the internal space of the chamber It is possible to quickly and surely adjust the temperature of the molding space on the side and the surface side space of the glass material, and consequently, it is possible to quickly and surely adjust the pressure in both spaces.

  Moreover, it is preferable that an auxiliary heating means is provided in the internal space of the heating furnace, and the internal space of the chamber is heated by the auxiliary heating means.

  In this way, it is possible to more quickly and reliably adjust the temperature of the molding space on the back side of the glass material that communicates with the internal space of the chamber and the surface side space of the glass material. This is advantageous in responding to a request for making the temperature of the molding space higher than the temperature of the surface side space of the glass material and making the pressure of the molding space higher than the pressure of the surface side space of the glass material.

  In the above method, it is preferable that the glass material has a flat plate-shaped portion where one or a plurality of recesses are formed.

  By doing so, it is possible to obtain an image sensor cover glass, a liquid crystal backlight glass, and the like having excellent quality.

On the other hand, an apparatus according to the present invention made to solve the above technical problem is a molding die in which one or a plurality of molding recesses and a vent hole leading to the inside of the molding recess are formed in the internal space of the heating furnace. In a state where the glass material is placed on the mold so as to cover the molding recess, a negative pressure is applied to the molding space surrounded by the molding recess and the back surface of the glass material through the vent hole. In the apparatus configured to mold a glass article in which one or a plurality of recesses are formed by acting, the entire bottom area of the mold and the entire bottom surface of the mold or substantially the entire area together with mounting the chamber cover from below, some or all of the chamber is positioned in the internal space of the furnace, and after heating the interior space of the inner space and the chamber of the furnace, said Chang Characterized in that constitutes the negative pressure in the internal space of so as to generate.

The invention according to this apparatus has substantially the same configuration as the invention according to the above method , and the operation and effect thereof are also substantially the same. Therefore, the description thereof is omitted here for convenience.

  As described above, according to the present invention, in the process of heating the glass material placed on the mold so as to cover the molding recess in the internal space of the heating furnace, the surface side space of the glass material and Since the temperature difference or atmospheric pressure difference with the molding space on the back side is appropriately adjusted, it becomes difficult for undue dent deformation to occur in the glass material before the suction by negative pressure, and the glass material is softened. It will be possible to achieve uniform uniformity over the entire area, and as a glass article having one or a plurality of recesses, it is possible to finally obtain a glass article that is close to the desired ideal shape and has a uniform thickness distribution. Become.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  First, based on FIG. 1, schematic structure of the shaping | molding apparatus of the glass article which concerns on 1st Embodiment of this invention is demonstrated. As shown in the figure, the molding apparatus 1 has one molding recess 3a having a substantially hemispherical shape formed in the upper surface of the internal space 2a of the heating furnace 2 and leading to the center of the bottom inside the molding recess 3a. The mold 3 is provided with a vent hole 3b. A chamber 4 is fixed to the bottom of the mold 3 and is entirely located in the internal space 2 a of the heating furnace 2, and the entire area of the side wall 4 c and the bottom wall 4 d of the chamber 4 is the internal space of the heating furnace 2. It is exposed to a high temperature atmosphere (hot air) in 2a. The internal space 4 a of the chamber 4 communicates with the inside of the molding recess 3 a through the vent hole 3 b of the molding die 3.

  Further, an exhaust pipe (communication path) 6 communicating with an exhaust device 5 disposed outside the heating furnace 2 is connected to the bottom wall portion 4 d of the chamber 4, and the internal space 4 a of the chamber 4 is operated by the operation of the exhaust device 5. Negative pressure is generated in the. The exhaust device 5 may be of any mechanism, but has a venturi mechanism that is particularly excellent in the responsiveness of the suction action. An open / close valve 7 that opens and closes the communication path in the exhaust pipe 6 is attached to the outside of the heating furnace 2 of the exhaust pipe 6. And in this 1st Embodiment, the heating source 8 is installed only in the inner surface side of the side wall part 2c of the heating furnace 2. As shown in FIG. The heating method of the heating source 8 may be based on heating wires or based on combustion gas. A pressing plate 9 is provided above the molding die 3 to hold and hold the peripheral edge of the glass plate G as a glass material placed on the upper surface of the molding die 3.

  According to such a configuration, when the glass plate G is placed on the upper surface of the mold 3, the molding space 3 x surrounded by the molding recess 3 a and the back surface of the glass plate G and the internal space 4 a of the chamber 4 are The exhaust pipe 6 is in a closed state by the open / close valve 7. Since the chamber 4 is entirely located in the internal space 2a of the heating furnace 2, the internal space 4a of the chamber 4 is heated by the hot air in the internal space 2a of the heating furnace 2 and is heated. Hot air does not escape from the internal space 4 a of the chamber 4 to the outside. Therefore, the temperature of the internal space 4a of the chamber 4 can be substantially equal to the temperature of the internal space 2a of the heating furnace 2, specifically, the temperature of the surface side space 2x of the glass plate G. Thereby, the temperature difference between the molding space 3x on the back side of the glass plate G communicating with the internal space 4a of the chamber 4 and the surface side space 2x of the glass plate G becomes substantially zero or extremely small. The atmospheric pressure difference between the two spaces 2x and 3x is also substantially zero or extremely small.

  As a result, in the process in which the glass plate G placed on the molding die 3 is heated so as to cover the molding recess 3a in the internal space 2a of the heating furnace 2, that is, in the process until suction by negative pressure is started. The glass plate G is unlikely to be unduely deformed due to the pressure difference. Therefore, it is possible to make it difficult to cause an inappropriate depression deformation until the softened state of the glass plate G is appropriately uniformed over the entire region. When the softened state of the glass plate G is made uniform as much as possible over the entire region and the glass plate G is sufficiently softened to be suitably deformed, the exhaust pipe 6 is opened by the opening / closing valve 7 to open the chamber 4. A negative pressure is applied to the molding space 3x from the inner space 4a through the vent hole 3b. As a result, the glass plate G is deformed while being properly fitted while being sucked into the molding recess 3a, and a glass article (for example, a glass container) having a single substantially hemispherical recess 10a as shown in FIG. 10 can be obtained. The glass article 10 as a whole has a high quality that is close to the target ideal shape and has a uniform thickness distribution.

  FIG. 3 illustrates a schematic configuration of the molding apparatus 1 according to the second embodiment of the present invention. The molding apparatus 1 according to the second embodiment is different from the molding apparatus 1 according to the first embodiment described above in that not only the inner surface side of the entire circumference of the side wall 2c of the heating furnace 2 but also the bottom of the heating furnace 2 is used. The heating source 8 is also installed on the inner surface side of the wall 2d. Since other configurations are the same as those of the molding apparatus 1 according to the first embodiment, common components are denoted by the same reference numerals, and description thereof is omitted. According to the molding apparatus 1 according to the second embodiment, since the chamber 4 is heated not only from the side but also from the lower side by the heating source 8, the heating process for the glass sheet G (suction by negative pressure is started). In the process up to this step, the temperature of the internal space 4a of the chamber 4, that is, the temperature of the molding space 3x, can be adjusted to be higher than the temperature of the surface side space 2x of the glass plate G by a predetermined temperature. Thus, the thickness of the glass plate G, the area of the glass plate G positioned on the molding recess 3a, or the glass plate G itself until the softened state of the glass plate G is appropriately uniformed over the entire area. Even if an inappropriate depression deformation is caused by its own weight due to the composition of the glass plate G, the pressure on the back surface side molding space 3x is higher than that on the front surface side space 2x. A force to lift is generated, and the glass plate G is maintained in a state along the plane. Accordingly, also in this case, substantially the same effect as that of the first embodiment described above can be obtained.

  FIG. 4 illustrates a schematic configuration of the molding apparatus 1 according to the third embodiment of the present invention. The molding apparatus 1 according to the third embodiment is different from the molding apparatus 1 according to the first embodiment described above in that the heating source 8 is installed on the inner surface side of the entire circumference of the side wall 2c of the heating furnace 2. In addition, an auxiliary heating source 8a as auxiliary heating means is provided on the outer surface of the chamber 4 (in the figure, the bottom wall portion 4d of the chamber 4). Since other configurations are the same as those of the molding apparatus 1 according to the first embodiment, common components are denoted by the same reference numerals, and description thereof is omitted. Even with the configuration of the third embodiment, the temperature of the internal space 4a of the chamber 4, that is, the temperature of the forming space 3x is adjusted to be higher than the temperature of the surface side space 2x of the glass plate G by a predetermined temperature. The same effects as those of the second embodiment described above can be obtained.

  FIG. 5 illustrates a schematic configuration of the molding apparatus 1 according to the fourth embodiment of the present invention. The molding apparatus 1 according to the fourth embodiment is different from the molding apparatus 1 according to the first embodiment described above in that the upper surface of the molding die 3 has a horizontal direction (left-right direction in the drawing) and a vertical direction (paper surface). A plurality of substantially hemispherical molding recesses 3a are formed in the direction orthogonal to each other, and the inner side (bottom center) of each molding recess 3a and the internal space 4a of the chamber 4 are communicated with each other via a vent hole 3b. It is a point. Since other configurations are the same as those of the molding apparatus 1 according to the first embodiment, common components are denoted by the same reference numerals, and description thereof is omitted. According to the configuration of the fourth embodiment, it is possible to manufacture the glass article 11 on which a large number of dimples 11a as shown in FIG. 6 are formed while obtaining the same operational effects as in the case of the first embodiment described above. it can. In the molding apparatus 1 according to the fourth embodiment, the heating source 8 is installed on the inner surface of the bottom wall portion 2d in the heating furnace 2 as in the second and third embodiments, or the chamber 4 An auxiliary heating source 8a may be installed on the outer surface.

  In the molding apparatus 1 according to the fifth embodiment of the present invention, the molding recess 3a formed in the molding die 3 shown in FIG. 5 has a plurality of groove-like recesses (in a direction perpendicular to the paper surface) having a substantially semicircular cross section. A glass article (for example, liquid crystal) in which a number of groove-like recesses 12a as shown in FIG. 7 are formed while obtaining the same operational effects as in the case of the first embodiment. Backlight glass) 12 can be manufactured. In addition, when said shaping | molding die 3 in this 5th Embodiment has a shaping | molding convex part which connects between adjacent shaping | molding recessed parts 3a smoothly, a corrugated glass article can be manufactured.

  FIG. 8 illustrates a schematic configuration of the molding apparatus 1 according to the sixth embodiment of the present invention. The molding apparatus 1 according to the sixth embodiment is different from the molding apparatus 1 according to the first embodiment described above in that only a part (upper part) of the chamber 4 is located in the internal space 2a of the heating furnace 2. It is a point. Since other configurations are the same as those of the molding apparatus 1 according to the first embodiment, common components are denoted by the same reference numerals, and description thereof is omitted. Even in the configuration of the sixth embodiment, a part of the chamber 4 is exposed to the hot air in the internal space 2a of the heating furnace 2, or an auxiliary heating source is installed on a part of the outer surface of the chamber 4. Since the internal space 4a of the chamber 4 can be at a high temperature, it is possible to obtain the same effect as in the case of the first embodiment described above.

  As Example 1 of the present invention, a rectangular glass plate G having a thickness of 1 mm, a length of 306 mm, and a width of 408 mm was formed using the forming apparatus 1 shown in FIG. A glass article 11 formed with a large number of dimples 11a having a depth of 10 mm was manufactured. In this case, the molding die 3 of the molding apparatus 1 is formed with a large number of molding recesses 3a corresponding to the above dimples and a large number of air holes 3b having a diameter of 0.5 mm. A stainless steel chamber 4 was attached. Further, the heating furnace 2 having an inner height of 400 mm is used, the bottom surface (outer bottom surface) of the chamber 4 is separated from the bottom surface (inner bottom surface) of the heating furnace 2 by 10 mm, and the bottom wall portion 4d of the chamber 4 is used. An exhaust pipe 6 made of a stainless steel pipe having a diameter of 10 mm was connected to the outside and pulled out to the outside of the heating furnace 2, and an exhaust device 5 having an open / close valve 7 and a venturi mechanism was installed. The heating source 8 was installed only on the side wall 2c, not on the ceiling wall and bottom wall 2d of the heating furnace 2.

  Using the molding apparatus 1 having such a structure, the above-described glass plate (thickness 1 mm, length 306 mm, width 408 mm) is placed on the mold 3 and heated while the open / close valve 7 of the exhaust pipe 6 is closed. Started. When the temperature of the glass plate G reached about 500 ° C. and was in a softened state, the furnace temperature was held at that temperature for 5 minutes. At the initial stage of 5 minutes, the glass plate G begins to soften from the contact portion with the mold 3, and the entire surface of the glass plate G is softened while being held for 5 minutes. There is a possibility that the glass plate G may be deformed by depression due to the weight of the glass plate G in a softened state on the molding recess 3a that is not in contact with the glass plate G. However, as described above, in addition to the fact that there is no atmospheric pressure difference that causes the glass plate G to be depressed and deformed, the diameter of the molding recess 3a is relatively small, about 10 mm. The shape of the glass plate G in the softened state was able to be maintained in a flat plate shape due to the fact that drooping was effectively suppressed. Then, after 5 minutes had elapsed, the heating was stopped to allow natural cooling, and the open / close valve 7 of the exhaust pipe 6 was fully opened to perform vacuum exhaust (suction by negative pressure). This evacuation is performed for 10 minutes with natural cooling, and after the evacuation is completed, the opening and closing valve 7 is kept fully open, and the temperature of the molding space 3x is made lower than the temperature of the surface side space 2x, thereby changing the pressure difference. In order to make the glass easily adhere to the molding recess 3a even during cooling. When the thickness distribution of the cooled glass article (glass article 11 shown in FIG. 6) was confirmed, the thickness variation could be suppressed to ± 0.05 mm.

  As Example 2 of the present invention, a square glass plate G having a thickness of 1.5 mm and a side of 100 mm is formed by using the forming apparatus 1 shown in FIG. A glass article 10 was produced in which a recess 10a having a diameter of 60 mm and a depth of 15 mm was formed in the center. In this case, the molding die 3 of the molding apparatus 1 includes a single molding recess 3a corresponding to the above-described recess 10a, and one vent hole 3b having a diameter of 0.5 mm leading to the center of the bottom of the molding recess 3a. A stainless steel chamber 4 was attached to the bottom of the mold 3. Further, as the heating furnace 2, one having an internal height of 300 mm is used, the outer bottom surface of the chamber 4 is separated from the inner bottom surface of the heating furnace 80 by 80 mm, and the bottom wall portion 4d of the chamber 4 is made of stainless steel having a diameter of 10 mm. An exhaust pipe 6 made of a pipe made was connected and pulled out of the heating furnace 2, and an exhaust device 5 having an opening / closing valve 7 and a venturi mechanism was installed. In addition to installing the heating source 8 on the side wall 2 c of the heating furnace 2, the auxiliary heating source 8 a is installed on the bottom wall 4 d of the chamber 4. As the auxiliary heating source 8a, a heating wire is used because it is advantageous in concentrating and heating the internal space 4a of the chamber 4.

  Using the molding apparatus 1 having such a structure, the above-described glass plate (thickness 1.5 mm, each side is 100 mm) is placed on the molding die 3, and the open / close valve 7 of the exhaust pipe 6 is closed. Heating was started. When the temperature of the glass plate G reached about 500 ° C. and was in a softened state, the furnace temperature was held at that temperature for 5 minutes. At the initial stage of 5 minutes, the glass plate G begins to soften from the contact portion with the mold 3, and the entire surface of the glass plate G is softened while being held for 5 minutes. There is a possibility that the glass plate G may be deformed by depression due to the weight of the glass plate G in a softened state on the molding recess 3a that is not in contact with the glass plate G. In particular, since the glass article 10 according to Example 2 has a large area of the recess 10a and a large plate thickness, the glass plate G in a softened state may be easily depressed due to its own weight. However, in the process in which the glass plate G is heated, the internal space 4a of the chamber 4 is positively heated by the auxiliary heating source 8a, and the temperature of the internal space 4a of the chamber 4 is higher than the furnace temperature (temperature of the surface side space 2x). The temperature was adjusted so that the temperature increased from 2 ° C. to 10 ° C. (preferably 5 ° C.). Thereby, the pressure of the molding space 3x on the back surface side of the glass plate G becomes higher than the pressure of the surface side space 2x, and the glass plate G is softened on the wide molding recess 3a by supporting the glass plate G with a pressure difference from below. It was possible to maintain the glass plate G in the flat plate shape. Then, after 5 minutes had elapsed, all heating was stopped and the system was allowed to cool naturally, and the exhaust valve 6 of the exhaust pipe 6 was fully opened to perform vacuum exhaust (suction by negative pressure). This evacuation is performed for 10 minutes with natural cooling, and after the evacuation is completed, the opening and closing valve 7 is kept fully open, and the temperature of the molding space 3x is made lower than the temperature of the surface side space 2x, thereby changing the pressure difference. In order to make the glass easily adhere to the molding recess 3a even during cooling. When the thickness distribution of the cooled glass article (glass article 10 shown in FIG. 2) was confirmed, the variation in thickness could be suppressed to ± 0.03 mm.

  In each of the above-described examples (each embodiment), the pressures of both the spaces 2x and 3x are adjusted by controlling the temperatures of the front surface side space 2x and the rear surface side forming space 3x of the glass plate G. However, by attaching a separate pressure control device such as a pressurization device or a decompression device to the heating furnace 2 or the chamber 4, the desired pressure may be applied to both the spaces 2x and 3x. The above-described temperature control in both the spaces 2x and 3x is not necessarily required.

  Moreover, in each above-mentioned Example (each embodiment), although the glass plate G was used as a glass-made raw material, outside this, for example, the outer side of the flat plate part in which the recessed part 10a (11a, 12a) should be formed A glass material that is not a mere glass plate may be used, such as a glass material having a peripheral wall portion that rises in the opposite direction to the recess direction of the concave portion 10a (11a, 12a).

It is a vertical front view which shows schematic structure of the shaping | molding apparatus which concerns on 1st Embodiment of this invention. It is a perspective view which shows the glass article produced using the shaping | molding apparatus which concerns on the said 1st Embodiment. It is a vertical front view which shows schematic structure of the shaping | molding apparatus which concerns on 2nd Embodiment of this invention. It is a vertical front view which shows schematic structure of the shaping | molding apparatus which concerns on 3rd Embodiment of this invention. It is a vertical front view which shows schematic structure of the shaping | molding apparatus which concerns on 4th, 5th embodiment of this invention. It is a perspective view which shows the glass article produced using the shaping | molding apparatus which concerns on the said 4th Embodiment. It is a perspective view which shows the glass article produced using the shaping | molding apparatus which concerns on the said 5th Embodiment. It is a vertical front view which shows schematic structure of the shaping | molding apparatus which concerns on 6th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Molding apparatus 2 Heating furnace 2a Heating furnace internal space 3 Mold 3a Molding recessed part 3b Vent hole 3x Molding space 4 Chamber 4a Chamber internal space 6 Communication path (exhaust pipe)
8a Auxiliary heating source (auxiliary heating means)
G Glass plate (glass material)

Claims (6)

A molding die in which one or a plurality of molding recesses and a vent hole leading to the inside of the molding recess is formed in the internal space of the heating furnace, and a glass material is molded so as to cover the molding recesses. In a state where the glass article is placed on a mold, a negative pressure is applied to the molding space surrounded by the molding recess and the back surface of the glass material, thereby molding a glass article having one or more recesses. In the method
At the bottom of the mold, a chamber that is connected to the vent hole and covers the entire bottom surface of the mold or substantially the entire region from below is mounted, and a part or all of the chamber is positioned in the internal space of the heating furnace. And after heating the internal space of the said heating furnace and the internal space of the said chamber, a negative pressure is generated in the internal space of this chamber, The shaping | molding method of the glass article characterized by the above-mentioned. The method for forming a glass article according to claim 1 , wherein the communication passage that communicates with the internal space so as to generate a negative pressure in the internal space of the chamber can be opened and closed. Located in the inner space of all of the heating furnace of the chamber, and molding method of a glass article according to claim 1 or 2 a bottom surface of said chamber characterized in that it moves away from the bottom of the furnace. The method for forming a glass article according to any one of claims 1 to 3 , wherein auxiliary heating means is provided in the internal space of the heating furnace, and the internal space of the chamber is heated by the auxiliary heating means. The method for molding a glass article according to any one of claims 1 to 4 , wherein the glass material has a flat plate-shaped portion forming the one or more recesses. A molding die in which one or a plurality of molding recesses and a vent hole leading to the inside of the molding recess is formed in the internal space of the heating furnace, and a glass material is molded so as to cover the molding recesses. In a state where the glass article is placed on a mold, a negative pressure is applied to the molding space surrounded by the molding recess and the back surface of the glass material, thereby molding a glass article having one or more recesses. In an apparatus configured as follows,
At the bottom of the mold, a chamber that is connected to the vent hole and covers the entire bottom surface of the mold or substantially the entire region from below is mounted, and a part or all of the chamber is positioned in the internal space of the heating furnace. The glass article forming apparatus is configured to generate a negative pressure in the internal space of the chamber after heating the internal space of the heating furnace and the internal space of the chamber.

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