JP2016003171A - Apparatus for producing glass molding and method for producing glass molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for producing glass molding and a method for producing glass molding capable of producing glass moldings with favorable appearance.SOLUTION: The apparatus for producing glass molding produces a glass mold with a noncircular plan view. The apparatus for producing glass molding comprises: a lower mold 21; an upper mold 31 for rough pressure forming which deforms the surface of molten glass; and an upper mold 41 for production pressure forming which pressure-forms the surface of the molten glass deformed by the upper mold 31 for rough pressure forming. The upper mold 31 for rough pressure forming and the upper mold 41 for production pressure forming include a recessed part 32 and a recessed part 42, respectively. The opening surface 34 of the recessed part 32 of the upper mold 31 for rough pressure forming corresponds in shape to the opening surface of the recessed part 42 of the upper mold 41 for production pressure forming, and has smaller outer dimensions than the opening surface of the recessed part 42. The recessed part 32 curves from the circumference 37 of the bottom part 36 to the bottom part 36 such that the upper mold 31 for rough pressure forming comes closer to the lower mold 21 in a facing direction, and consequently has a step part 38 to provide a step between the opening surface 34 and the bottom part 36.

Description

  TECHNICAL FIELD The present invention generally relates to a glass molded body manufacturing apparatus and a glass molded body manufacturing method, and more specifically, to a glass molded body manufacturing apparatus and glass molding using a direct press method for manufacturing a glass molded body. The present invention relates to a method for manufacturing a body.

  Regarding a conventional method for producing a glass molded body, for example, Japanese Patent Application Laid-Open No. 2008-94654 discloses that an optical element having a high-precision optical surface is made high by uniformizing the cooling rate at the center and end of molten glass. A manufacturing method of an optical element for the purpose of manufacturing with production efficiency is disclosed (Patent Document 1). The method for manufacturing an optical element disclosed in Patent Document 1 includes a step of cooling a molten glass by bringing a cooling member into contact with the upper surface of the molten glass supplied to a molding die, and molding for pressure-molding the molten glass. Process.

  Japanese Patent Laid-Open No. 2008-230863 discloses a high-precision optical surface that prevents the occurrence of air accumulation even in the case of manufacturing an optical element having a convex optical surface by transfer of the molding surface of the upper mold. A method of manufacturing an optical element for the purpose of efficiently manufacturing an optical element having an optical element is disclosed (Patent Document 2).

  The method of manufacturing an optical element disclosed in Patent Document 2 includes a step of supplying molten glass onto a lower mold combined with side walls, a step of retracting the side walls from the lower mold, and a lower mold and an upper mold. And pressing the glass. During the process of supplying the molten glass onto the lower mold, the molten glass on the lower mold is adjusted by the side wall so that the radius of curvature of the central portion of the upper surface of the molten glass is smaller than the radius of curvature of the central portion of the molding surface of the upper mold. regulate. In the step of pressure-molding the molten glass with the lower mold and the upper mold, the optical surface is formed by transferring the molding surface of the upper mold to the center of the upper surface of the molten glass.

  Further, JP 2008-239423 A discloses a highly accurate optical surface that prevents the occurrence of air accumulation even in the case of manufacturing an optical element having a convex optical surface by transfer of the molding surface of the upper mold. A method for manufacturing an optical element for the purpose of efficiently manufacturing an optical element having an optical element is disclosed (Patent Document 3).

  The method of manufacturing an optical element disclosed in Patent Document 3 includes a step of supplying molten glass to a receiving surface of a lower mold, and a concave surface in which the radius of curvature of the central portion is smaller than the radius of curvature of the central portion of the molding surface of the upper die And a step of deforming the upper surface of the molten glass into a predetermined convex shape and a step of pressure-molding the molten glass with an upper die and a lower die. At the time of pressure forming the molten glass with the lower mold and the upper mold, the optical surface is formed by transferring the molding surface of the upper mold to the upper surface of the molten glass.

JP 2008-94654 A JP 2008-230863 A JP 2008-239423 A

  Cover glasses provided in display devices typified by smartphones and tablet terminals are widely used. A direct press method in which a glass material (molten glass) melted by a mold is pressure-molded is used for manufacturing a glass molded body in which such a cover glass is an example. However, when manufacturing a glass molded body having a non-circular plan view such as a rectangle, such as a cover glass of a smartphone, from the reason described below, a shape warp, a decrease in transferability in a corner shape, wrinkles, An air pool etc. generate | occur | produces and the glass molded object of a favorable external appearance cannot be obtained.

  Here, it is assumed that molten glass is dropped on the lower mold and a rectangular cover glass is manufactured by the recess provided on the upper mold. As the pressure forming process by the direct press method, there are a case where only the main pressing process is performed without the rough pressing process and a case where the rough pressing process is performed and then the main pressing process is performed.

  When performing only this press process, since the temperature of the molten glass before this press is high (for example, 1000-1100 degreeC), the viscosity of a molten glass is low. For this reason, at the time of this press process, a molten glass can be spread over the four corners of the recessed part which has a shape corresponding to a cover glass, and a favorable corner shape can be obtained. However, the molten glass easily adheres to the surface of the mold, and shape warpage occurs.

  On the other hand, when the rough mold pressing step is performed and then the main pressing step is performed, the temperature of the molten glass before the main pressing step is low (for example, 800 to 900 ° C.), so the viscosity of the molten glass is high. In this case, although the above-described shape warpage is improved, the transferability in the corner shape is lowered, and wrinkles and air accumulation are generated due to the low fluidity of the molten glass.

  Accordingly, an object of the present invention is to solve the above-described problems, and to provide a glass molded body manufacturing apparatus and a glass molded body manufacturing method capable of obtaining a glass molded body having a good appearance.

  The manufacturing apparatus of the glass molded body according to this invention is an apparatus which manufactures the glass molded body which has a non-circular planar view. The apparatus for producing a glass molded body includes a first mold to which molten glass is supplied, a second mold that is disposed to face the first mold and deforms the surface of the molten glass on the first mold, A third mold for pressing the molten glass disposed opposite to the first mold and deformed by the second mold. Each of the second mold and the third mold is filled with molten glass, and is filled with a first recess that forms a first opening surface that opens to the side facing the first mold, and molten glass, A second recess is provided that forms a second opening surface that opens to the side facing the first mold. The second opening surface has a non-circular plan view when viewed from the first mold side. The first opening surface has a shape corresponding to the second opening surface and smaller than the second opening surface when viewed from the first mold side. The first recess is bent so that the second mold is closer to the first mold in the direction facing the first mold, and the first bottom provided to face the first opening, and the peripheral edge of the first bottom. And a step portion that provides a step between the first bottom portion.

  In the present invention, “non-circular” means a shape other than a circle having a constant distance from the center to the outer edge.

  According to the glass molded body manufacturing apparatus configured as described above, the molten glass is deformed inside the first recess by the step portion during the step of deforming the surface of the molten glass on the first die by the second die. The molten glass is spread to the corners of the first recesses, and the first recesses are filled with the molten glass. Accordingly, a preform having a shape corresponding to the second opening surface and having an outer shape smaller than the second opening surface in a plan view and having a favorable corner shape is prepared. Further, the preform is pressure-molded by using a third mold to spread the molten glass to the corner of the second recess, and the shape of the glass molded body is defined by the wall surface of the second recess. Thereby, the glass molded object of a favorable external appearance can be obtained.

  Preferably, when the first opening surface and the second opening surface are overlapped with each other centered, the length of the gap between the peripheral edge of the first opening surface and the peripheral edge of the second opening surface is: It is the range of 1 mm or more and 2 mm or less.

  According to the glass molded body manufacturing apparatus configured as described above, the molten glass can be easily filled up to the corners of the second recesses during the pressure molding using the third mold.

  Further preferably, the depth of the first recess from the first opening surface is greater than the depth of the second recess from the second opening surface.

  According to the glass molded body manufacturing apparatus configured in this way, the height of the portion of the preform whose surface shape is determined by the wall surface of the first recess is greater than the depth of the second recess. Thereby, at the time of pressure molding using the third mold, the preform can be deformed more smoothly so that the molten glass reaches the corner of the second recess.

  Preferably, the first bottom portion is configured by a curved surface that is convex in a direction away from the first mold.

  According to the glass molded body manufacturing apparatus configured as described above, the preform portion whose surface shape is determined by the wall surface of the first bottom portion is formed into a curved shape that is convex in a direction away from the first mold. Is done. Thereby, at the time of pressure molding using the third mold, the preform can be more smoothly deformed so as not to cause wrinkles or air accumulation on the surface of the glass molded body.

  Preferably, the second concave portion has a second bottom portion provided to face the second opening surface. The curvature radius of the first bottom portion is smaller than the curvature radius of the second bottom portion.

  According to the glass molded body manufacturing apparatus configured as described above, the occurrence of wrinkles and air accumulation on the surface of the glass molded body can be more reliably prevented during pressure molding using the third mold.

  Preferably, the first bottom portion has a plan view having a relatively large length in the longitudinal direction and a relatively small length in the short direction when viewed from the first mold side. The curvature radius of the 1st bottom part in a longitudinal direction is larger than the curvature radius of the 1st bottom part in a transversal direction.

  According to the apparatus for manufacturing a glass molded body configured in this way, at the start of pressure molding using the third mold, the preform portion whose surface shape is determined by the wall surface of the first bottom portion is entirely covered. It becomes possible to make it approach to the wall surface of a 2nd recessed part.

  Preferably, the length of the gap between the peripheral edge of the first opening surface and the peripheral edge of the second opening surface is constant when the first opening surface and the second opening surface are overlapped with each other in the center. It is. Preferably, the first opening surface is similar to the second opening surface.

  According to the glass molded body manufacturing apparatus configured as described above, the second mold is suitable for pressure molding using the third mold by the step of deforming the surface of the molten glass on the first mold by the second mold. Shape preforms can be prepared.

  The method for manufacturing a glass molded body according to the present invention is a method for manufacturing a glass molded body having a non-circular plan view. The method for producing a glass molded body includes a step of supplying molten glass to a first mold, and a second mold disposed opposite to the first mold so that the surface of the molten glass on the first mold is formed. After the step of deforming and the step of deforming the surface of the molten glass by the second mold, the molten glass on the first mold is pressure-molded by the third mold disposed opposite to the first mold. And a step of performing. Each of the second mold and the third mold is filled with molten glass, and is filled with a first recess that forms a first opening surface that opens to the side facing the first mold, and molten glass, A second recess is provided that forms a second opening surface that opens to the side facing the first mold. The second opening surface has a non-circular plan view when viewed from the first mold side. The first opening surface has a shape corresponding to the second opening surface and smaller than the second opening surface when viewed from the first mold side. The first recess is bent so that the second mold is closer to the first mold in the direction facing the first mold, and the first bottom provided to face the first opening, and the peripheral edge of the first bottom. And a step portion that provides a step between the first bottom portion.

  According to another aspect of the present invention, a method for manufacturing a glass molded body includes a first mold and a first opening surface that is disposed to face the first mold and opens to a side facing the first mold. A second mold provided with a first recess to be formed, and a second mold provided with a second recess that is disposed opposite to the first mold and forms a second opening surface that opens on the side facing the first mold. This is a method for producing a glass molded body having a non-circular plan view using a three mold. The second opening surface has a non-circular plan view when viewed from the first mold side. The first opening surface has a shape corresponding to the second opening surface and smaller than the second opening surface when viewed from the first mold side. The method for producing a glass molded body includes a step of supplying molten glass to a first mold, and deforming the surface of the molten glass on the first mold by the second mold, whereby the molten glass is applied to the first recess. After the step of filling and the step of deforming the surface of the molten glass by the second mold, the molten glass on the first mold is pressure-molded by the third mold, thereby forming the molten glass at the corner of the second recess. And a step of defining the shape of the glass molded body by the wall surface of the second recess.

  According to the manufacturing method of the glass molded body comprised in this way, the glass molded body of a favorable external appearance can be obtained.

  Further preferably, in the step of pressing the molten glass with the third mold, the portion of the molten glass whose surface shape is determined by the wall surface of the first recess at the timing when the third mold first contacts the molten glass. Is positioned near the corner of the second recess.

  According to the method for producing a glass molded body configured as described above, the preform prepared using the second mold is pushed to the corner of the second recess during the pressure molding using the third mold. It can be spread out to obtain a glass molded article having a good appearance.

  Preferably, the molten glass on the first mold has an elliptical plan view when supplying the molten glass to the first mold.

  According to the manufacturing method of the glass molded body comprised in this way, it can be easy to fill a 1st recessed part with molten glass at the time of the process of deforming the surface of the molten glass on a 1st metal mold | die by a 2nd metal mold | die.

  As described above, according to the present invention, a glass molded body manufacturing apparatus and a glass molded body manufacturing method capable of obtaining a glass molded body having a good appearance can be provided.

It is a schematic block diagram which shows the manufacturing apparatus of the glass molded object in embodiment of this invention. It is a figure which shows the planar layout of the manufacturing apparatus of the glass forming body shown in FIG. It is sectional drawing which shows the metal mold | die used in a rough mold press part. It is another sectional view which shows the metal mold | die used in a rough mold press part. It is the bottom view which looked at the upper mold | type for rough | crude press used in a rough | crude press part from the lower mold | type side. It is sectional drawing which shows the metal mold | die used in this press part. It is another sectional view which shows the metal mold | die used in this press part. It is the bottom view which looked at the upper mold for this press used in this press part from the lower mold side. FIG. 9 is a diagram in which an opening surface of a recess provided in the upper die for rough press in FIG. 5 and an opening surface of a recess provided in the upper die for press in FIG. 8 are superimposed. It is sectional drawing which expands and shows the range enclosed with the dashed-two dotted line X in FIG. It is a flowchart which shows the manufacturing method of the glass forming body in embodiment of this invention. It is a figure which shows the process of the manufacturing method of the glass forming body in embodiment of this invention. It is a figure which shows the next process of the manufacturing method of the glass forming body in embodiment of this invention. It is a figure which shows the next process of the manufacturing method of the glass forming body in embodiment of this invention. It is a figure which shows the next process of the manufacturing method of the glass forming body in embodiment of this invention. It is a figure which shows the next process of the manufacturing method of the glass forming body in embodiment of this invention. It is a figure which shows the next process of the manufacturing method of the glass forming body in embodiment of this invention. It is a figure which shows the next process of the manufacturing method of the glass forming body in embodiment of this invention. In Examples 1-4 and Comparative Examples 1-3, it is a table | surface which shows evaluation of the external appearance of the obtained glass molded object.

  Embodiments of the present invention will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are denoted by the same reference numerals.

(Embodiment)
FIG. 1 is a schematic configuration diagram showing a glass molded body manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing a planar layout of the glass molded body manufacturing apparatus shown in FIG.

  With reference to FIG. 1 and FIG. 2, first, the whole structure of the manufacturing apparatus 10 of the glass molded object in this Embodiment is demonstrated. The glass molded body manufacturing apparatus 10 is based on a so-called direct press method in which a glass material (molten glass) melted by a mold is pressed to obtain a glass molded body. The glass molded body manufacturing apparatus 10 sequentially manufactures a plurality of glass molded bodies.

  The glass molded body manufacturing apparatus 10 includes a material supply unit 120 (dropping position P1), a pressure molding unit 130 (rough die press position P2 and main press position P3), a cooling unit 150 (cooling position P4), a separation unit. A mold part 160 (release position P5) and a cleaning part 170 (cleaning position P6) are combined.

  The material supply unit 120 melts the glass material and supplies the molten glass to the subsequent pressure forming unit 130. The material supply unit 120 includes a melting furnace 181, a nozzle unit 182, an outflow pipe 183, and a cutting unit 140.

  The melting furnace 181 melts the glass material and stores the molten glass. The nozzle unit 182 introduces the molten glass stored in the melting furnace 181 into the outflow pipe 183. The outflow pipe 183 has an outflow port at the lower end thereof, and allows the molten glass flow to flow out continuously from the outflow port vertically downward.

  The cutting unit 140 cuts the molten glass flow flowing out from the outflow pipe 183 and drops an appropriate amount of molten glass onto the lower mold 21 described later. The cutting unit 140 includes a cutter 142 as a cutting mechanism and a cutter driving mechanism 143.

  The cutter 142 is provided as a cutting member that cuts the molten glass flow flowing out from the outflow pipe 183. In the present embodiment, the cutter 142 is configured by a pair of planar shear blades, and the pair of shear blades are abutted below the outflow pipe 183 to cut the molten glass flow.

  The cutter driving mechanism 143 drives the cutter 142 in the direction indicated by the arrow DR1 in FIG. The cutter driving mechanism 143 is not particularly limited as long as it is a driving mechanism capable of cutting the cutter 142. For example, an air cylinder, a servo motor, a hydraulic cylinder, a linear motor, a stepping motor, or the like is used.

  The pressure molding unit 130 press-molds the molten glass supplied from the material supply unit 120 using the mold 30. The pressure molding unit 130 includes a rough press unit 130P (rough press position P2) and a main press unit 130Q (main press position P3).

  The pressure molding unit 130 includes a lower die 21, a rough press upper die 31 and a main press upper die 41, a lower die drive mechanism 132, an upper die drive mechanism 131, and an upper die drive mechanism 141.

  The upper die 31 for rough press and the lower die 21 constitute a mold 30 for press-molding molten glass in the rough press portion 130P, and the upper die 41 for press and the lower die 21 are provided for the press portion 130Q. A mold 30 for press-molding molten glass is configured. The lower mold 21 receives the molten glass dropped from the material supply unit 120 at the dropping position P1. The upper die 31 for rough die pressing is arranged to face the lower die 21 at the rough die press position P2. The upper die 41 for the press is disposed to face the lower die 21 at the press position P3.

  Examples of the material for forming the mold 30 include heat-resistant alloys (stainless alloys, etc.), super steel materials mainly composed of tungsten carbide, various ceramics (silicon carbide, silicon nitride, aluminum nitride, etc.), composite materials containing carbon, etc. As a mold for producing a glass molded article, it is appropriately selected from known materials and used. The lower die 21, the rough die upper die 31 and the main die 41 may be made of the same material, or may be made of different materials.

  The surface of the mold 30 is preferably covered with a predetermined coating layer from the viewpoint of improving durability and preventing fusion with a molten glass material. The material of the coating layer is not particularly limited. For example, various metals (chromium, aluminum, titanium, etc.), nitrides (chromium nitride, aluminum nitride, titanium nitride, boron nitride, etc.), oxides (oxidation) Chromium, aluminum oxide, titanium oxide, etc.) are used. The method for forming the coating layer is not particularly limited, and for example, a vacuum deposition method, a sputtering method, a CVD (Chemical Vapor Deposition) method, or the like is used.

  The mold 30 is configured to be heated to a predetermined temperature by a heating unit (not shown). As the heating means, known heating means are appropriately selected and used. For example, a cartridge heater embedded in the heated member, a sheet heater used in contact with the outside of the heated member, infrared rays, for example A heating device, a high frequency induction heating device, or the like is used.

  The lower mold drive mechanism 132 moves the lower mold 21 in the direction (horizontal direction) indicated by the arrow DR2 in FIGS. As a result, the lower mold 21 has a position where the molten glass is dropped onto the lower mold 21 (dropping position P1) and a position facing the upper mold 31 for rough pressing in order to roughly press the molten glass (rough mold press position). P2), a position (main press position P3) facing the upper mold 41 for main pressing to press the molten glass, a position for cooling the glass molded body (cooling position P4), and glass from the mold It moves between a position for removing the molded body (release position P5) and a position for cleaning the surface of the lower mold 21 (cleaning position P6).

  In addition, the moving direction of the lower mold | type 21 is not limited to the turning direction shown in FIG. 2, For example, a linear motion direction may be sufficient.

  The lower mold drive mechanism 132 is not particularly limited as long as it can move the lower mold 21. For example, a servo motor, an air cylinder, a hydraulic cylinder, a linear motor, a stepping motor, or a combination thereof may be used. Used. In FIG. 2, the lower mold drive mechanism 132 includes a turntable 136 and a motor (not shown) that rotationally drives the turntable 136.

  The upper die drive mechanism 131 moves the upper die 31 for rough die pressing in the direction (vertical direction) indicated by the arrow DR3 in FIG. As a result, the upper die 31 for rough die press reciprocates between the position on the vertical upper side and the position on the lower vertical side, and the upper die 31 for coarse die press and the lower die 21 approach and separate from each other. . The upper die drive mechanism 141 moves the upper die 41 for the press in the direction (vertical direction) indicated by the arrow DR4 in FIG. As a result, the upper die 41 for the press reciprocates between the position on the vertical upper side and the position on the lower vertical side, and the upper die 41 for the press and the lower die 21 approach and separate from each other.

  The upper die drive mechanism 131 and the upper die drive mechanism 141 are not particularly limited as long as the upper die 31 for rough press and the upper die 41 for main press can be moved. For example, a servo motor, An air cylinder, a hydraulic cylinder, a linear motor, a stepping motor, or a combination thereof is used.

  The cooling unit 150 cools the glass molded body obtained by the pressure molding unit 130. In the present embodiment, cooling unit 150 is provided as a standby position for lower mold 21 on which a glass molded body is mounted.

  The mold release part 160 takes out the glass molded body obtained by the pressure molding part 130 from the mold 30 (lower mold 21). The release part 160 has a suction device 161. The suction device 161 is provided so as to face the lower mold 21 positioned at the mold release position P5. As the adsorption device 161, for example, a known means using vacuum adsorption is used.

  The cleaning unit 170 cleans the surface of the lower die 21 in a state where the lower die 21 is separated from the rough press upper die 31 and the main press upper die 41. In the present embodiment, the cleaning unit 170 cleans the surface of the lower mold 21 positioned at the cleaning position P6 by suction.

  The cleaning unit 170 includes a suction nozzle 171, a suction nozzle drive mechanism 172, and a suction unit 173.

  The suction nozzle 171 is provided so as to face the lower mold 21 and sucks glass waste remaining on the surface of the lower mold 21. The suction nozzle 171 opens facing the surface of the lower mold 21 and sucks glass waste together with the surrounding air. The suction part 173 includes a negative pressure generation source for sucking glass waste through the suction nozzle 171 and a glass waste recovery part for recovering the sucked glass waste.

  The suction nozzle drive mechanism 172 moves the suction nozzle 171 so that the suction port 171 a of the suction nozzle 171 is scanned on the surface of the lower mold 21. The suction nozzle drive mechanism 172 is not particularly limited as long as the suction nozzle 171 can be moved. For example, a servo motor, an air cylinder, a hydraulic cylinder, a linear motor, a stepping motor, or a combination thereof can be used. Used.

  The glass molded body manufacturing apparatus 10 includes a control unit 180. The control unit 180 is a glass molded body manufacturing apparatus 10 such as a cutter driving mechanism 143, a lower mold driving mechanism 132, an upper mold driving mechanism 131, an upper mold driving mechanism 141, a suction device 161, a suction nozzle driving mechanism 172, and a suction unit 173. Control the operation of various mechanisms. The control unit 180 includes a timing for cutting the molten glass by the cutter 142, a timing for moving the lower die 21, a timing for moving the upper die 31 for rough die pressing and the upper die 41 for main press, and a timing for operating the suction device 161. A series of sequences relating to the manufacture of the glass molded product, such as the timing of movement of the suction nozzle 171 and the timing of operation of the suction unit 173, are controlled.

  The glass molded body manufactured by using the glass molded body manufacturing apparatus 10 in the present embodiment and the glass molded body manufactured by the method for manufacturing a glass molded body in the present embodiment described later are in a non-circular plan view. Have Non-circular shapes include, for example, a rectangle, a trapezoid, a polygon, an ellipse, and a track shape (a shape in which two semicircles are connected by two straight lines).

  An example of the glass molded body is a cover glass provided in a smartphone. The cover glass is typically formed in a flat plate shape having a rectangular plan view. The cover glass is not limited to a rectangular plan view, and may have, for example, a shape in which a corner portion of the rectangle is chamfered or a polygonal plan view. The cover glass is not limited to a flat plate shape. For example, the cover glass may have a shallow saucer shape by folding the outer edge to one side over the entire circumference.

The cover glass has a glass composition of 50% by weight to 70% by weight SiO ₂ , 5% by weight to 15% by weight Al ₂ O ₃ , and 0% by weight to 5% by weight B ₂ O ₃ . 5 to 20% by weight Na ₂ O, 0 to 10% by weight K ₂ O, 0 to 10% by weight MgO, 0 to 10% by weight and CaO, and 0 wt% to 5 wt% of BaO, 0 and wt% to 5 wt% or less of TiO _2, it may be contained and ZrO ₂ 0 wt% to 15 wt% or less.

  When the glass transition temperature is Tg, the glass having such a composition greatly affects the shape transferred to the glass in pressure molding (Tg-30) [° C.] or more and (Tg + 150) [° C.] or less. Surface transfer can be completed in a state where an appropriate glass viscosity is maintained in a temperature range and good transferability is ensured, and cracking due to thermal shrinkage of the glass can be suppressed.

The linear expansion coefficient α of the glass is preferably 70 or more and 110 [× 10 ⁻⁷ / ° C.] or less in a temperature range of 100 [° C.] or more and 300 [° C.] or less. For example, a glass having a linear expansion coefficient α of 98 [× 10 ⁻⁷ / ° C.] in the range of 100 ° C. to 300 ° C. may be used. Further, when the glass viscosity is η [dPa · s], log η = 11.0 to 14.5 is preferable. Glass having the above characteristics is suitable for forming a cover glass by the direct press method.

  Next, assuming the production of a cover glass having a rectangular plan view, the structure of the mold 30 used in the rough press part 130P and the main press part 130Q will be described in more detail.

  3 and 4 are cross-sectional views showing a mold used in the rough die press section. FIG. 5 is a bottom view of the upper die for rough die press used in the rough die press portion as seen from the lower die side. 3 shows a cross-sectional shape of the upper die for rough pressing along the line III-III in FIG. 5, and FIG. 4 shows the upper shape for rough pressing along the line IV-IV in FIG. The cross-sectional shape of the mold is shown.

  With reference to FIGS. 3 to 5, the lower mold 21 is a mold for storing the molten glass supplied by the material supply unit 120. The lower die 21 press-molds molten glass in cooperation with the upper die 31 for rough die press and the upper die 41 for main press in the rough die pressing step and the subsequent main pressing step, respectively.

  The lower die 21 has a die surface 21a on the side facing the upper die 31 for rough die pressing. The mold surface 21a is formed in a planar shape.

  The upper die 31 for rough die pressing is a die for deforming the surface of the molten glass on the lower die 21 during the rough die pressing step to obtain a preform having a shape suitable for this pressing step. The upper die 31 for rough die pressing has a die surface 31 a on the side facing the lower die 21. The mold surface 21a and the mold surface 31a are provided facing each other.

  The upper die 31 for rough die pressing is provided with a recess 32 filled with molten glass during the rough die pressing step. The concave portion 32 has a concave shape on the mold surface 31a. The recess 32 gives the molten glass on the lower mold 21 a shape suitable for the pressing process. The recess 32 forms an opening surface 34 that opens to the side facing the lower mold 21. The opening surface 34 is an imaginary surface and is defined at a position surrounded by the opening edge 33 of the recess 32 having a concave shape on the mold surface 31a. The opening surface 34 extends in a plane perpendicular to the direction in which the upper die 31 for rough die pressing faces the lower die 21.

  6 and 7 are cross-sectional views showing a mold used in the press section. FIG. 8 is a bottom view of the upper die for the press used in the press portion as viewed from the lower die side. 6 shows a cross-sectional shape of the upper die for pressing along the line VI-VI in FIG. 8, and FIG. 7 shows the upper die for pressing along the line VII-VII in FIG. The cross-sectional shape is shown.

  With reference to FIG. 6 to FIG. 8, the upper die 41 for press is used to press-mold the preform obtained in the rough press process during the press process to obtain a final glass molded body. It is a mold. The upper die 41 for press has a die surface 41 a on the side facing the lower die 21. The mold surface 21a and the mold surface 41a are provided to face each other.

  The upper die 41 for press is provided with a recess 42 filled with molten glass during the press process. The concave portion 42 has a concave shape on the mold surface 41a. The recess 42 gives the final shape of the glass molded body to the molten glass on the lower mold 21. The recess 42 forms an opening surface 44 that opens to the side facing the lower mold 21. The opening surface 44 is a virtual surface, and is defined at a position surrounded by the opening edge 43 of the concave portion 42 having a concave shape on the mold surface 41a. The opening surface 42 extends in a plane perpendicular to the direction in which the upper die 41 for pressing opposes the lower die 21.

  The opening surface 44 has a non-circular plan view when viewed from the lower mold 21 side. In the present embodiment assuming the production of a rectangular cover glass, the opening surface 44 has a rectangular plan view. The recessed part 42 has the bottom part 46 as the component. The bottom 46 is formed in a planar shape. The wall surface of the bottom 46 is a flat surface extending in parallel with the opening surface 44. The bottom 46 is provided to face the opening surface 44. The recess 42 (bottom 46) has a depth h4 with respect to the opening surface 44.

  FIG. 9 is a diagram in which the opening surface of the recess provided in the upper die for rough press in FIG. 5 and the opening surface of the recess provided in the upper die for press in FIG. 8 are superimposed. Referring to FIGS. 3 to 5 and 9, opening surface 34 has a shape corresponding to opening surface 44 and smaller than opening surface 44 when viewed from the lower mold 21 side.

  More specifically, the opening surface 34 has a rectangular shape with an outer shape smaller than the opening surface 44 when viewed from the lower mold 21 side. When the opening surface 34 and the opening surface 44 are overlapped with each other centered, the opening edge 33 serving as the periphery of the opening surface 34 is located inside the opening edge 43 serving as the periphery of the opening surface 44. It is circling along. In the present embodiment, the length B (see FIG. 9) of the gap between the opening edge 33 and the opening edge 43 is constant over the entire circumference of the opening edge 33 and the opening edge 43. The length B of the gap between the opening edge 33 and the opening edge 43 is preferably in the range of 1 mm to 2 mm. In this case, it becomes easy to fill the molten glass up to the corner of the recess 42 during the pressing process.

  The opening surface 34 and the opening surface 44 may be configured such that the length B of the gap between the opening edge 33 and the opening edge 43 is not constant in the circumferential direction of the opening edge 33 and the opening edge 43. Moreover, you may comprise the opening surface 44 and the opening surface 34 so that it may become a similar relationship. Even in these cases, the length B of the gap between the opening edge 33 and the opening edge 43 is preferably within the range of 1 mm to 2 mm.

  FIG. 10 is an enlarged cross-sectional view of a range surrounded by a two-dot chain line X in FIG. With reference to FIGS. 3 to 5 and 10, the recess 32 has a bottom portion 36 and a stepped portion 38 as its constituent parts.

  The recess 32 has a depth h <b> 1 with respect to the opening surface 34. The concave portion 32 is a position where the center of the opening surface 34 is projected onto the concave portion 32 (position 106 in FIGS. 3 and 4) in the opposing direction (vertical direction) of the lower die 21 and the upper die 31 for rough die pressing. It has a maximum depth h1. The depth h1 of the recess 32 is larger than the depth h4 of the recess 42 in FIGS. 6 and 7 (h1> h4).

  The bottom portion 36 is provided so as to face the opening surface 34. The bottom portion 36 is configured by a curved surface that is convex toward the direction away from the lower mold 21. The bottom portion 36 has a depth from the opening surface 34 at a position where the center of the opening surface 34 is projected onto the bottom portion 36 in the opposing direction (vertical direction) of the lower die 21 and the rough die upper die 31 (see FIG. 3 and FIG. 3). It is configured by a curved surface that becomes maximum at a position 106) in FIG. 4 and gradually decreases as the distance from the position in the radial direction increases. The curvature radius of the bottom portion 36 is smaller than the curvature radius of the bottom portion 46 in FIGS. 6 and 7 (infinite in the present embodiment).

  When viewed from the lower mold 21 side, the bottom portion 36 has a relatively long length direction (direction shown by an arrow 102 in FIG. 5) and a relatively short length direction (in FIG. 5). A plan view of a rectangular shape having a direction indicated by an arrow 103 of FIG. The curvature radius r1 (see FIG. 3) of the bottom portion 36 in the longitudinal direction is larger than the curvature radius r2 (see FIG. 4) of the bottom portion 36 in the short direction.

  The stepped portion 38 is a direction in which the upper die 31 for rough press shown in FIG. 10 is opposed to the lower die 21 from the peripheral edge 37 of the bottom portion 36 (hereinafter referred to as “opposite direction of the upper die 31 for rough die press”). And a step is provided between the opening surface 34 and the bottom portion 36.

  More specifically, the stepped portion 38 is provided between the peripheral edge 37 of the bottom portion 36 and the opening edge 33 of the concave portion 32. The wall surface of the concave portion 32 is bent at the peripheral edge 37 at the boundary between the bottom portion 36 and the stepped portion 38.

  The step portion 38 has a steeper slope than the bottom portion 36 with respect to the opening surface 34. In FIG. 10, a virtual surface 36 u obtained by extending the bottom portion 36 from the peripheral edge 37 is shown. The angle θ1 formed between the facing direction of the rough press upper mold 31 indicated by the arrow 101 in FIG. 10 and the wall surface of the stepped portion 38 is the facing direction of the rough press upper mold 31 indicated by the arrow 101 in FIG. And an angle θ2 formed by the virtual surface 36u. When the angle θ1 formed by the facing direction of the upper die 31 for rough press shown by the arrow 101 in FIG. 10 and the wall surface of the stepped portion 38 is positive, the stepped portion 38 does not have a negative angle θ1. (Angle θ1 ≧ 0). The opening area of the recess 32 when cut by a plane (horizontal plane) orthogonal to the opposing direction of the upper die 31 for rough die press gradually increases as the recess 32 approaches the opening surface 34 from the position having the maximum depth h1. . At this time, the rate of increase in the opening area of the recess 32 (increase rate) is smaller in the stepped portion 38 than in the bottom portion 36.

  FIG. 10 shows the case where the wall surface of the bottom portion 36 and the wall surface of the step portion 38 are bent and connected, but the wall surface of 36 and the wall surface of the step portion 38 are curved and connected. May be. In the cross section shown in FIG. 10, the stepped portion 38 is configured by a single inclined surface, but is not limited to such a configuration, and may be configured by combining a plurality of inclined surfaces having different inclinations. Good. The step part 38 (height between the opening surface 34 and the peripheral edge 37) has a depth h2, and the bottom part 36 (height between the peripheral edge 37 and the deepest part of the bottom part 36) has a depth h3 ( h2 + h3 = h1). In the present embodiment, the bottom portion 36 and the stepped portion 38 are provided so as to satisfy the relationship of h2> h3. The configuration is not limited to such a configuration, and the bottom portion 36 and the stepped portion 38 may be provided so as to satisfy the relationship of h2 ≦ h3.

  Then, the manufacturing method of the glass molded product in embodiment of this invention is demonstrated. FIG. 11 is a flowchart showing a method for manufacturing a glass molded body in the embodiment of the present invention. 12 to 18 are views showing steps of the method for manufacturing a glass molded body in the embodiment of the present invention.

  The manufacturing method of the glass molded body in this Embodiment is based on what is called a direct press method, and is suitably implemented using the manufacturing apparatus 10 of the glass molded body in this Embodiment mentioned above. Moreover, the manufacturing method of the glass molded object in this Embodiment manufactures a several glass molded object sequentially by repeating the series of processes mentioned later.

  Referring to FIG. 1, in the method for manufacturing a glass molded body in the present embodiment, mold 30 is heated in advance to a predetermined temperature by the heating means described above. Here, the predetermined temperature means a temperature at which a good transfer surface can be formed on the glass molded body.

  Generally, if the temperature of the mold 30 is too low, it becomes difficult to form a highly accurate transfer surface on the glass molded body. On the other hand, if the temperature of the mold 30 is increased too much more than necessary, fusion may easily occur between the mold 30 and the molten glass, or the life of the mold 30 may be shortened. Therefore, it is not preferable.

  For example, the temperature of the mold 30 is set in the range of (Tg−100) [° C.] to (Tg + 100) [° C.] with respect to the glass transition temperature Tg [° C.] of the glass material to be pressure-molded. Actually, an appropriate temperature is determined in consideration of various conditions such as the type of glass material, the shape and size of the glass molded product, the forming material of the mold 30 and the type of protective film. The heating temperature of each mold constituting the mold 30 may be the same temperature or a different temperature.

  In the method for manufacturing a glass molded body in the present embodiment, after the mold 30 is heated to a predetermined temperature, the molten glass in a high temperature state is pressure-molded using the mold 30. In this case, a series of steps to be described later can be performed while keeping the temperature of the mold 30 constant. Furthermore, it is possible to sequentially manufacture a plurality of glass molded bodies while keeping the temperature of the mold 30 constant. Therefore, since it is not necessary to repeat heating and cooling of the mold 30 every time one glass molded body is manufactured, a plurality of glass molded bodies can be efficiently manufactured in an extremely short time.

  Here, keeping the temperature of the mold 30 constant means that the target set temperature in the temperature control for heating the mold 30 is kept constant. Therefore, it is not intended to prevent even the temperature fluctuation of the mold 30 due to the contact of the molten glass or the like during the execution of each process described later, and such temperature fluctuation is allowable.

  Referring to FIG. 11, first, lower mold 21 is moved to dropping position P1 in FIGS. 1 and 2 (S101). As a result of detecting the current position of the lower mold 21, if the lower mold 21 is already arranged at the dropping position P1, the lower mold 21 is not moved. On the other hand, as a result of detecting the current position of the lower mold 21, when the lower mold 21 is arranged at a position other than the dropping position P 1, the lower mold driving mechanism 132 is operated by a command from the control unit 180, and the lower mold 21 is operated. 21 is moved to the dropping position P1.

  Next, the molten glass is caused to flow out of the melting furnace 181 and cut by the cutter 142 (S102). The glass material stored in the melting furnace tank 181 in the melted state flows out of the melting furnace tank 181 via the nozzle part 182 and falls in a liquid line form as a molten glass stream from the outflow pipe 183 by its own weight. The molten glass flow flowing out from the outflow pipe 183 is cut by the cutter 142 to obtain molten glass having a drop-like shape. The molten glass falls toward the lower mold 21.

  With reference to FIG. 11 and FIG. 12, molten glass is dripped at the lower mold | type 21 (S103). The molten glass that is cut and dropped by the cutter 142 is received on the lower mold 21, and the received molten glass wets and spreads on the mold surface 21 a of the lower mold 21. At this time, the molten glass on the lower mold 21 preferably has an elliptical plan view. In this case, in the subsequent rough pressing process, it becomes easy to fill the recessed glass 32 with the rectangular opening surface 34 with molten glass. The “elliptical shape” here means an ellipse in a strict sense mathematically defined (a curve formed from a set of points such that the sum of distances from two fixed points on a plane is constant). Rather than refer to, it simply refers to an oval shape having a major axis and a minor axis.

  Referring to FIGS. 11 and 13, next, lower die 21 is moved from dropping position P1 to rough die press position P2, and a rough die pressing step is performed (S104). The lower die drive mechanism 132 is operated by a command from the control unit 180, and the lower die 21 is moved to the rough die press position P2. As a result, the lower die 21 is disposed opposite to the upper die 31 for rough die pressing at a distance. The upper die driving mechanism 131 is operated by a command from the control unit 180, and the upper die 31 for rough die pressing is lowered toward the lower die 21. The molten glass is pressure-formed while being pressed between the mold surface 21 a of the lower mold 21 and the mold surface 31 a of the upper mold 31 for rough mold pressing.

  Preferably, the glass transition temperature is set to Tg, the temperature of the upper die 31 for rough die pressing is set to (Tg−40) ° C. or more and (Tg + 10) ° C. or less, and the temperature of the lower die 21 is set to (Tg−20) ° C. The temperature is set to (Tg + 40) ° C. or lower. For example, when Tg is 570 ° C., the temperature of the upper die 31 for rough die pressing is set to 550 ° C., and the temperature of the lower die 21 is set to 580 ° C.

  As the upper die 31 for rough die press moves closer to the lower die 21, the molten glass is deformed so as to fill the concave portion 32, and further between the die surface 21a and the die surface 31a from the concave portion 32. Deforms to enter the space. In the present embodiment, the molten glass is spread to the corners of the recess 32 by surrounding the molten glass deformed inside the recess 32 by the stepped portion 38. As a result, a preform 210 having a favorable corner shape is obtained. The preform 210 has a portion 210 t formed by melting glass filling the recess 32.

  The upper die drive mechanism 131 is actuated by a command from the control unit 180 to raise the upper die 31 for rough die press. At this time, the preform 210 obtained in the rough die pressing step is separated from the upper die 31 for rough die pressing and remains on the lower die 21.

  Referring to FIGS. 11, 14, and 15, next, lower die 21 is moved from rough die press position P <b> 2 to main press position P <b> 3 to perform the main press step (S <b> 105). The lower mold drive mechanism 132 is actuated by a command from the controller 180, and the lower mold 21 is moved to the press position P3. As a result, the lower die 21 is disposed to face the upper die 41 for the press at a distance. The upper die drive mechanism 141 is operated by a command from the control unit 180, and the upper die 41 for pressing is lowered toward the lower die 21. The preform 210 obtained in the previous step is pressure-formed while being pressed between the mold surface 21a of the lower mold 21 and the mold surface 41a of the upper mold 41 for the press.

  Preferably, the temperature of the upper die 41 for press is set to (Tg-100) ° C. or higher and (Tg-40) ° C. or lower with respect to the glass transition temperature Tg, and the temperature of the lower die 21 is set to (Tg-20). It is set to ℃ or more and (Tg + 40) ℃ or less. For example, when Tg is 570 ° C., the temperature of the upper die 41 for press is set to 500 ° C., and the temperature of the lower die 21 is set to 580 ° C.

  In FIG. 14, the timing when the upper die 41 for press that descends toward the lower die 21 first contacts the preform 210 is shown. The portion 210t of the preform 210 formed by filling the concave portion 32 has a shape corresponding to the opening surface 44 of the concave portion 42 and a smaller outer shape than the opening surface 44 in plan view. For this reason, at the start of this pressing step shown in FIG. 14, the portion 210 t of the preform 210 is positioned in the vicinity of the corner of the recess 42. The length B in the horizontal direction between the portion 210t of the preform 210 and the corner of the recess 42 is preferably in the range of 1 mm to 2 mm.

  FIG. 15 shows the timing when the upper die 41 for the press is lowered to the target position. When the upper die 41 for press is further lowered, as shown in FIG. 15, the portion 210 t of the preform 210 is pushed up to the corner of the recess 42 and filled into the recess 42. Thereby, a glass molded body 220 whose shape is defined by the wall surface of the recess 42 is obtained.

  In the present embodiment, as described above, a preform 210 that matches the shape of the concave portion 42 is prepared by a rough press process, and the preform 210 is fully pressed, so that the corner shape is particularly excellent. An external glass molded body 220 can be obtained.

  Furthermore, in the present embodiment, the depth h1 of the concave portion 32 is made larger than the depth h4 of the concave portion 42 in the upper die 31 for rough pressing and the upper die 41 for main pressing, whereby the portion 210t of the preform 210 is formed. The height is higher than the depth of the bottom 46. Moreover, in the upper die 31 for rough die pressing, the bottom portion 36 is configured by a curved surface that protrudes in a direction away from the lower die 21, so that the shape of the bottom portion 36 is transferred to the portion 210 t of the preform 210. A similar curved shape is obtained. By pressing the preform 210 having such a shape with the wall surface of the bottom 46 having a planar shape, the portion 210t of the preform 210 is sequentially spread from the top to the periphery thereof. As a result, the molten glass is filled up to the corners of the recesses 42, and the corner shape of the glass molded body 220 can be further improved. Further, it is possible to effectively prevent wrinkles and air accumulation in the glass molded body 220.

  The upper die drive mechanism 141 is actuated by a command from the control unit 180, and the upper die 41 for the press is raised. At this time, the glass molded body 220 obtained in the pressing process is separated from the pressing upper mold 41 and remains on the lower mold 21.

  Referring to FIGS. 11 and 16, next, the lower die 21 is moved from the main press position P3 to the cooling position P4, and the cooling process is performed (S106). The lower mold drive mechanism 132 is operated by a command from the control unit 180, and the lower mold 21 is moved to the cooling position P4. By making the lower mold 21 stand by at the cooling position P4, the glass molded body 220 obtained in the present pressing process is cooled.

  Referring to FIG. 11 and FIG. 17, next, the lower mold 21 is moved from the cooling position P4 to the mold release position P5, and a mold release process is performed (S107). The lower mold drive mechanism 132 is operated by a command from the control unit 180, and the lower mold 21 is moved to the mold release position P5. The mold release operation of the glass molded body 220 is performed using, for example, a known mold release device such as a suction device using vacuum suction. Thereby, the glass molded body 220 is taken out from the lower mold 21 and collected. The glass molded body 220 recovered from the lower mold 21 is subjected to an appropriate cutting step and / or polishing step, whereby a final shape of a glass product such as a cover glass is obtained.

  Referring to FIGS. 11 and 18, next, the lower mold 21 is moved from the mold release position P5 to the cleaning position P6, and a cleaning process is performed (S108). The lower mold drive mechanism 132 is operated by a command from the control unit 180, and the lower mold 21 is moved to the cleaning position P6. By operating the suction unit 173 in FIG. 1, a negative pressure is generated at the suction port 171 a of the suction nozzle 171. By operating the suction nozzle drive mechanism 172, the suction port 171 a of the suction nozzle 171 is scanned on the surface of the lower mold 21.

  The structure of the glass molded body manufacturing apparatus 10 according to the embodiment of the present invention described above and the process of the glass molded body manufacturing method will be described together. The glass molded body manufacturing apparatus 10 in the present embodiment is as follows. It is an apparatus for producing a glass molded body having a non-circular plan view. The glass molded body manufacturing apparatus 10 includes a lower mold 21 serving as a first mold to which molten glass is supplied, and a second mold that is disposed to face the lower mold 21 and deforms the surface of the molten glass on the lower mold 21. An upper die 31 for rough die press as a die and a main die as a third die for press-molding molten glass which is arranged facing the lower die 21 and deformed by the upper die 31 for coarse die press An upper die 41 is provided. The upper die 31 for rough die press and the upper die 41 for main press are each filled with molten glass and form a first recess that forms an opening surface 34 as a first opening surface that opens to the side facing the lower die 21. And a concave portion 42 as a second concave portion that is filled with molten glass and forms an opening surface 44 as a second opening surface that opens to the side facing the lower mold 21. The opening surface 44 has a non-circular plan view when viewed from the lower mold 21 side. The opening surface 34 has a shape corresponding to the opening surface 44 when viewed from the lower mold 21 side, and has an outer shape smaller than the opening surface 44. The concave portion 32 is bent from the bottom portion 36 as the first bottom portion provided facing the opening surface 34 and the peripheral edge 37 of the bottom portion 36 so that the upper die 31 for rough die pressing approaches the lower die 21 in a closer direction. A step portion 38 is provided between the surface 34 and the bottom portion 36 to provide a step.

  Moreover, the manufacturing method of the glass forming body in this Embodiment is a method of manufacturing the glass forming body which has a non-circular planar view. The method for producing a glass molded body includes a step of supplying molten glass to a lower mold 21 as a first mold, and an upper mold 31 for rough mold pressing as a second mold disposed to face the lower mold 21. Thus, after the step of deforming the surface of the molten glass on the lower die 21 and the step of deforming the surface of the molten glass by the upper die 31 for rough mold pressing, the third mold disposed to face the lower die 21 And a step of press-molding the molten glass on the lower die 21 with the upper die 41 for the press. The upper die 31 for rough die press and the upper die 41 for main press are each filled with molten glass and form a first recess that forms an opening surface 34 as a first opening surface that opens to the side facing the lower die 21. And a concave portion 42 as a second concave portion that is filled with molten glass and forms an opening surface 44 as a second opening surface that opens to the side facing the lower mold 21. The opening surface 44 has a non-circular plan view when viewed from the lower mold 21 side. The opening surface 34 has a shape corresponding to the opening surface 44 when viewed from the lower mold 21 side, and has an outer shape smaller than the opening surface 44. The concave portion 32 is bent from the bottom portion 36 as the first bottom portion provided facing the opening surface 34 and the peripheral edge 37 of the bottom portion 36 so that the upper die 31 for rough die pressing approaches the lower die 21 in a closer direction. A step portion 38 is provided between the surface 34 and the bottom portion 36 to provide a step.

  Moreover, the manufacturing method of the glass molded object in this Embodiment is arrange | positioned facing the lower mold | type 21 and the lower mold | type 21 as a 1st metal mold | die, and the 1st opening surface opened on the side facing the lower mold | type 21 The upper die 31 for rough pressing as a second die provided with a recess 32 as a first recess for forming an opening surface 34 as the side, and the side opposite to the lower die 21 and disposed on the lower die 21 Glass having a non-circular plan view using a main die 41 for press as a third mold provided with a recess 42 as a second recess for forming an opening surface 44 as a second opening surface opened in This is a method for producing a molded body. The opening surface 44 has a non-circular plan view when viewed from the lower mold 21 side. The opening surface 34 has a shape corresponding to the opening surface 44 when viewed from the lower mold 21 side, and has an outer shape smaller than the opening surface 44. The method for producing a glass molded body includes a step of supplying molten glass to the lower mold 21 and deforming the surface of the molten glass on the lower mold 21 with the upper mold 31 for rough mold pressing, whereby the molten glass is applied to the recess 32. After the step of filling and the step of deforming the surface of the molten glass with the upper die 31 for rough die pressing, the molten glass on the lower die 21 is pressure-molded by the upper die 41 for pressing so that the molten glass is recessed. And a process of demarcating to the corner of 42 and defining the shape of the glass molded body by the wall surface of the recess 42.

  According to the glass molded body manufacturing apparatus 10 and the glass molded body manufacturing method in the embodiment of the present invention configured as described above, the shape of the concave portion 42 of the upper mold 41 for the press is matched by a rough pressing process. By preparing the preform 210 and subjecting the preform 210 to main press, a glass molded body having excellent corner shape and having no appearance defects such as shape warpage, wrinkles, air accumulation, striae, and the like can be obtained.

(Example)
A glass molded body was manufactured using the glass molded body manufacturing apparatus 10 in the present embodiment described above. At this time, in Examples 1 to 4, the upper die 31 for rough die press provided with the stepped portion 38 was used. For comparison, Comparative Examples 1 and 2 use the upper die 31 for rough pressing in which the stepped portion 38 is not provided. In Comparative Example 3, the outer shape of the opening surface 34 of the recess 32 is the opening surface 44 of the recess 42. The upper die 31 for rough press larger than the outer shape of was used. Specifically, in Examples 1 to 4 and Comparative Examples 1 to 3, a rough press upper die 31 having the following shape was used (for L1, L2, h2, and h3, refer to FIGS. See
“Comparative Example 1” The mold surface 31a has a planar shape “Comparative Example 2”. The concave part “Example 1” having a spherical concave shape (φ58 mm, center depth 3 mm) is formed on the mold surface 31a. Portion 38: 118 mm (L 1) × 58 mm (L 2), depth 2 mm (h 2), recess 36 having a bottom portion 36 (planar shape)
Example 2 A box-shaped concave shape (stepped portion 38: 118 mm (L1) × 58 mm (L2), depth 2 mm (h2), bottom portion 36: curved concave shape (depth 1 mm (h3)) on the mold surface 31a Recess 32
Example 3 A box-shaped concave shape (stepped portion 38: 116 mm (L1) × 56 mm (L2), depth 2 mm (h2), bottom portion 36: curved concave shape (depth 1 mm (h3)) on the mold surface 31a Recess 32
Example 4 A box-shaped concave shape (stepped portion 38: 114 mm (L1) × 54 mm (L2), depth 2 mm (h2), bottom portion 36: curved concave shape (depth 1 mm (h3)) on the mold surface 31a Recess 32
“Comparative Example 3” Box-shaped concave shape (stepped portion 38: 122 mm (L1) × 62 mm (L2), depth 2 mm (h2), bottom portion 36: curved concave shape (depth 1 mm (h3)) Further, in Examples 1 to 4 and Comparative Examples 1 to 3, the upper die 41 for the present press in FIGS. 6 to 8 having dimensions of 120 mm (L3) × 60 mm (L4) and a depth of 2 mm (h4). Was used.

The manufacturing conditions of the glass molded bodies in Examples 1 to 4 and Comparative Examples 1 to 3 were set as follows.
“Glass material” Aluminosilicate glass “Glass transition temperature Tg” 570 [° C.]
“Linear expansion coefficient α” 98 [× 10 ⁻⁷ / ° C.] in a temperature range of 100 ° C. to 300 ° C.
“Dimensions of glass molded body” 120 × 60 × thickness 2.0 [mm]
“Temperature of upper die 31 for rough press” 550 [° C.]
"Temperature of upper die 41 for this press" 500 [° C]
"Temperature of lower mold 21" 580 [° C]
"Rough die press time" 0.8 [s]
"Rough die press pressure" 0.5 [t]
"Center surface temperature of the upper surface of the preform after completion of rough press" 870 ° C
“Main press time” 6.0 [s]
"Pressing pressure" 2.0 [t]
“Center surface temperature of the upper surface of the glass molding after completion of this press” 590 ° C
FIG. 19 is a table showing the evaluation of the appearance of the glass molded bodies obtained in Examples 1 to 4 and Comparative Examples 1 to 3. The appearances (shape sled, four-corner shape, wrinkle, air reservoir) of the glass molded bodies produced according to Examples 1 to 4 and Comparative Examples 1 to 3 were observed, and the respective evaluations are shown in FIG. In FIG. 19, “A”, “B”, “C”, and “D” are shown in order from the one with the best evaluation.

  Referring to FIG. 19, in Examples 1 to 4 using the upper die 31 for rough press provided with a stepped portion 38, the appearance is excellent in any of the shape sled, the four corner shape, the wrinkle, and the air reservoir. A glass molded body of was obtained. In particular, in Example 2 and Example 3 in which the bottom portion 36 has a curved concave shape and the length B of the gap between the opening edge 33 and the opening edge 43 is in the range of 1 mm to 2 mm, the glass having an extremely excellent appearance. A molded body could be obtained.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is mainly applied to the production of a glass molded body using a direct press method.

  DESCRIPTION OF SYMBOLS 10 Glass forming body manufacturing apparatus, 21 Lower mold | type, 21a, 31a, 41a Mold surface, 30 Mold, 31 Upper mold | type for rough type | mold press, 32, 42 Recessed part, 33, 43 Open edge, 34, 44 Open face, 36 , 46 Bottom, 36u Virtual surface, 37 Perimeter, 38 Stepped portion, 41 Upper mold for pressing, 106 Position, 120 Material supply unit, 130 Pressure forming unit, 130P Rough die pressing unit, 130Q Main pressing unit, 131,141 Upper mold drive mechanism, 132 Lower mold drive mechanism, 136 Turntable, 140 Cutting unit, 142 Cutter, 143 Cutter drive mechanism, 150 Cooling unit, 160 Mold release unit, 161 Suction device, 170 Cleaning unit, 171 Suction nozzle, 171a Suction 172, suction nozzle drive mechanism, 173 suction unit, 180 control unit, 181 melting furnace tank, 182 nozzle unit 183 Outflow pipe, 210 preform, 210t part, 220 glass molded body.

Claims (12)

An apparatus for producing a glass molded body having a non-circular plan view,
A first mold to which molten glass is supplied;
A second mold that is disposed opposite the first mold and deforms the surface of the molten glass on the first mold;
A third mold that is arranged opposite to the first mold and press-molds the molten glass deformed by the second mold;
Each of the second mold and the third mold is filled with molten glass, and a first recess that forms a first opening surface that opens to a side facing the first mold, and a molten glass is provided. A second recess is provided that forms a second opening surface that is filled and opens on a side facing the first mold;
The second opening surface has a non-circular plan view when viewed from the first mold side,
The first opening surface has a shape corresponding to the second opening surface when viewed from the first mold side, and has an outer shape smaller than the second opening surface;
The first recess is bent from a first bottom provided facing the first opening surface, and a peripheral edge of the first bottom so that the second mold is closer to a direction facing the first mold, An apparatus for manufacturing a glass molded body, comprising: a step portion that provides a step between the first opening surface and the first bottom portion.   When the first opening surface and the second opening surface are overlapped with each other centered, the length of the gap between the peripheral edge of the first opening surface and the peripheral edge of the second opening surface is: The manufacturing apparatus of the glass molded object of Claim 1 which is the range of 1 mm or more and 2 mm or less.   3. The glass molded body manufacturing apparatus according to claim 1, wherein a depth of the first recess from the first opening surface is greater than a depth of the second recess from the second opening surface.   The said 1st bottom part is a manufacturing apparatus of the glass molded object of any one of Claim 1 to 3 comprised by the curved surface which becomes convex toward the direction away from the said 1st metal mold | die. The second recess has a second bottom portion provided to face the second opening surface,
5. The glass molded body manufacturing apparatus according to claim 4, wherein a curvature radius of the first bottom portion is smaller than a curvature radius of the second bottom portion. The first bottom portion, as viewed from the first mold side, has a plan view having a relatively long longitudinal direction and a relatively small short length direction;
The glass molded body manufacturing apparatus according to claim 4 or 5, wherein a radius of curvature of the first bottom portion in the longitudinal direction is larger than a radius of curvature of the first bottom portion in the short direction.   When the first opening surface and the second opening surface are overlapped so that their centers coincide with each other, the length of the gap between the periphery of the first opening surface and the periphery of the second opening surface is constant. The manufacturing apparatus of the glass molded object of any one of Claim 1 to 6 which is.   The said 1st opening surface is a manufacturing apparatus of the glass molded object of any one of Claim 1 to 7 which is a similar shape of the said 2nd opening surface. A method for producing a glass molded body having a non-circular plan view,
Supplying molten glass to the first mold;
A step of deforming a surface of the molten glass on the first mold by a second mold disposed to face the first mold;
After the step of deforming the surface of the molten glass with the second mold, a step of pressure-molding the molten glass on the first mold with a third mold disposed opposite to the first mold And
Each of the second mold and the third mold is filled with molten glass, and a first recess that forms a first opening surface that opens to a side facing the first mold, and a molten glass is provided. A second recess is provided that forms a second opening surface that is filled and opens on a side facing the first mold;
The second opening surface has a non-circular plan view when viewed from the first mold side,
The first opening surface has a shape corresponding to the second opening surface when viewed from the first mold side, and has an outer shape smaller than the second opening surface;
The first recess is bent from a first bottom provided facing the first opening surface, and a peripheral edge of the first bottom so that the second mold is closer to a direction facing the first mold, The manufacturing method of a glass forming body which has a level | step difference part which provides a level | step difference between a said 1st opening surface and a said 1st bottom part. A second mold provided with a first mold and a first recess that is disposed opposite to the first mold and that forms a first opening surface that opens on a side facing the first mold; Non-circular plan view using a third mold provided opposite to the first mold and provided with a second recess forming a second opening surface that opens to the side facing the first mold. A method for producing a glass molded body having
The second opening surface has a non-circular plan view when viewed from the first mold side,
The first opening surface has a shape corresponding to the second opening surface when viewed from the first mold side, and has an outer shape smaller than the second opening surface;
Supplying molten glass to the first mold;
Filling the molten glass in the first recess by deforming the surface of the molten glass on the first mold by the second mold;
After the step of deforming the surface of the molten glass with the second mold, the molten glass is pressure-molded with the third mold to form the molten glass at the corner of the second recess. And a step of defining the shape of the glass molded body by the wall surface of the second recess.   During the step of pressure-molding the molten glass with the third mold, at the timing when the third mold first contacts the molten glass, a portion of the molten glass whose surface shape is defined by the wall surface of the first recess is The method for producing a glass molded body according to claim 10, wherein the glass molded body is positioned in the vicinity of a corner of the second recess.   12. The glass molded body according to claim 9, wherein during the step of supplying molten glass to the first mold, the molten glass on the first mold has an elliptical plan view. Production method.

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