JP2015137202A - Glass molding manufacturing method, and glass molding manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass molding manufacturing method for preventing the degradation of a glass molding by the occurrence of glass waste production, and a glass molding manufacturing apparatus.SOLUTION: A method for manufacturing in a direct press method a glass molding having a non-circular plane view, comprises the steps of: feeding a molten glass material to a lower die 31; pressure-molding the glass material by using the lower die 31 fed with the glass material and an upper die arranged to face the lower die 31; separating the lower die 31 and the upper die thereby to release the glass molding; and cleaning the surface 31a of the lower die 31 by suction after the step of releasing the glass molding.

Description

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

  Regarding a conventional method for producing a glass molded product, for example, Japanese Patent Application Laid-Open No. 2003-226528 discloses a lens element molding apparatus and a molding method for the purpose of preventing a change in shape and damage of a mold. (Patent Document 1).

  A lens element molding apparatus disclosed in Patent Document 1 includes an upper mold having a curved surface for pressure-molding a lens element made of glass, a lower mold disposed to face the upper mold, and a lower mold. And a sleeve extending in a cylindrical shape from the lower mold toward the upper mold. At the time of molding the lens element, a glass material is supplied to the lower mold. Next, the lower mold is raised and the sleeve is inserted into the upper mold. Thereafter, the glass material is sandwiched and molded between the upper mold and the lower mold.

  Japanese Patent Application Laid-Open No. 2012-101992 discloses a method for producing a glass molded body for the purpose of favorably transferring molten glass droplets to the molding surfaces of the upper mold and the lower mold. (Patent Document 2).

  In the manufacturing method of the glass molded object disclosed by patent document 2, the molten glass droplet supplied on the lower mold | type is pressure-molded with an upper mold | type and a lower mold | type using a dripping nozzle. At this time, by measuring the expected drop position of the molten glass drop on the lower mold in advance, the deviation between the expected drop position and the desired drop position is such that the molten glass drop falls to the desired drop position on the lower mold. The lower mold is positioned based on the amount.

JP 2003-226528 A JP 2012-101992 A

  Cover glasses provided in display devices typified by smartphones and tablet terminals are widely used. As a method for producing a glass molded product, an example of such a cover glass is a direct press method in which a glass material melted by a mold including a lower mold and an upper mold is pressed.

  However, when manufacturing a large, irregular (rectangular, etc.) glass molded product, such as a smartphone cover glass, by the direct press method, depending on the amount of glass material supplied and molding conditions, burrs may occur in the glass molded product, Glass debris may remain on the lower mold after releasing the glass molded product. When the production of the glass molded product is repeated in such a state, there is a concern that the quality of the glass molded product is deteriorated, for example, foreign matters are mixed inside the glass and the appearance of the glass molded product is defective.

  Here, assuming the case where the molten glass material is dropped into the lower mold and the outer shape of the glass molded product is formed by the recess formed in the upper mold, the peripheral edge of the opening surface of the recess may be formed into a sharp edge shape. preferable. Thereby, at the time of pressure molding, the glass material can be spread to every corner of the recess, and the shape of the recess can be accurately transferred to the glass molded product. However, in this case, since the molding pressure locally rises at the peripheral edge portion having the sharp edge shape, there is a possibility that the glass dust adheres to the upper mold separated from the glass molded product. When such glass waste falls from the upper mold onto the lower mold, a phenomenon that the glass waste is mixed into the glass molded product is particularly likely to occur.

  On the other hand, as a means for preventing glass dust from entering the inside of the glass molded product, a method of blowing glass dust on the lower mold with air can be considered. However, with such a method, the blown glass scraps may be mixed into other molds or dripping portions of the glass material, and the quality deterioration of the glass molded product cannot be prevented sufficiently.

  Accordingly, an object of the present invention is to solve the above-described problems, and to provide a glass molded product manufacturing method and a glass molded product manufacturing apparatus that prevent deterioration of the quality of a glass molded product due to generation of glass waste.

  The method for producing a glass molded product according to the present invention is a method for producing a glass molded product having a non-circular plan view by a direct press method. The method for producing a glass molded product includes a step of supplying a molten glass material to a first mold, a first mold supplied with the glass material, and a second mold disposed to face the first mold. After the step of pressure-molding the glass material using the mold, the step of separating the first mold and the second mold, releasing the glass molded product, and the step of releasing the glass molded product, Cleaning the surface of the first mold by suction.

  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 method for manufacturing a glass molded product configured as described above, after the step of releasing the glass molded product, the surface of the first mold is cleaned by suction, whereby glass is formed on the surface of the first mold. Prevents debris from remaining. Thereby, the quality degradation of the glass molded product by generation | occurrence | production of glass waste can be prevented.

  Preferably, the second mold has an opening surface having a shape corresponding to a non-circular plan view of the glass molded product when viewed from the first mold side, and press-molds the glass material. A recess filled with a glass material is formed during the process. The recess has a sharp edge shape at the peripheral edge of the opening surface.

  According to the method for manufacturing a glass molded product configured as described above, glass dust is generated in the second mold separated from the glass molded product by locally increasing the molding pressure at the peripheral edge having a sharp edge shape. There is a possibility of adhesion. As a result, a phenomenon in which glass scraps are mixed into the glass molded product is particularly likely to occur. Therefore, the effect of the present invention that prevents the deterioration of the quality of the glass molded product by cleaning the surface of the first mold is more effectively exhibited. Can do.

  Preferably, the step of cleaning the surface of the first mold includes a step of sucking a position facing the second mold during the step of pressure-molding the glass material. According to the manufacturing method of the glass molded product comprised in this way, the quality fall of the glass molded product by generation | occurrence | production of glass waste can be prevented more reliably.

  Further preferably, the step of cleaning the surface of the first mold sucks a position facing the peripheral edge of the glass material deformed between the first mold and the second mold during the step of pressing the glass material. Process. According to the manufacturing method of the glass molded product comprised in this way, the quality fall of the glass molded product by generation | occurrence | production of glass waste can be prevented more reliably.

  The apparatus for producing a glass molded product according to the present invention is a device for producing a glass molded product having a non-circular plan view by a direct press method. An apparatus for manufacturing a glass molded product includes a first mold to which a molten glass material is supplied and a second mold that is disposed to face the first mold and press-molds the glass material together with the first mold. And a cleaning unit for cleaning the surface of the first mold by suction in a state where the first mold and the second mold are separated.

  According to the glass molded product manufacturing apparatus configured as described above, the first mold and the second mold are separated from each other, by providing the cleaning unit that cleans the surface of the first mold by suction. 1 to prevent glass dust from remaining on the surface of the mold. Thereby, the quality degradation of the glass molded product by generation | occurrence | production of glass waste can be prevented.

  Preferably, the cleaning unit has a suction nozzle having a suction port that opens to face the surface of the first mold, and suction that moves the suction nozzle so that the suction port is scanned on the surface of the first mold. Nozzle drive mechanism.

  According to the glass molded product manufacturing apparatus configured in this manner, glass waste on the surface of the first mold can be reliably collected in a shorter time.

  As described above, according to the present invention, it is possible to provide a glass molded product manufacturing method and a glass molded product manufacturing apparatus that prevent deterioration of the quality of the glass molded product due to generation of glass waste.

It is a schematic block diagram which shows the manufacturing apparatus of the glass molded product in embodiment of this invention. It is a figure which shows the planar layout of the manufacturing apparatus shown in FIG. It is a flowchart which shows the manufacturing method of the glass molded product in embodiment of this invention. It is sectional drawing which shows the 1st process of the manufacturing method of the glass molded product in embodiment of this invention. It is sectional drawing which shows the 2nd process of the manufacturing method of the glass molded product in embodiment of this invention. It is sectional drawing which shows the 3rd process of the manufacturing method of the glass molded product in embodiment of this invention. It is sectional drawing which shows the 4th process of the manufacturing method of the glass molded product in embodiment of this invention. It is another sectional drawing which shows the 4th process of the manufacturing method of the glass molded product in embodiment of this invention. It is another sectional drawing which shows the 4th process of the manufacturing method of the glass molded product in embodiment of this invention. It is sectional drawing which shows the 5th process of the manufacturing method of the glass molded product in embodiment of this invention. It is sectional drawing which shows the 6th process of the manufacturing method of the glass molded product in embodiment of this invention. It is a top view which shows the 7th process of the manufacturing method of the glass molded product in embodiment of this invention. It is sectional drawing which shows the 7th process of the manufacturing method of the glass molded product in embodiment of this invention. It is another sectional drawing which shows the 7th process of the manufacturing method of the glass molded product in embodiment of this invention. It is sectional drawing which expands and shows the range enclosed with the dashed-two dotted line XV in FIG. In an Example and a comparative example, it is a table | surface which shows the external appearance defect rate by the foreign material of a glass molded product.

  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.

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

  With reference to FIG. 1 and FIG. 2, the structure of the manufacturing apparatus 100 of the glass molded product in this Embodiment is demonstrated first. The glass molded product manufacturing apparatus 100 is based on a so-called direct press method in which a glass material melted by a mold is pressed to obtain a glass molded product. The glass molded product manufacturing apparatus 100 sequentially manufactures a plurality of glass molded products.

  The glass molded product manufacturing apparatus 100 according to the present embodiment includes a material supply unit 10, a cutting unit 20, a pressure molding unit 30, a mold release unit 40, a cleaning unit 50, and a control unit 60. These are configured in combination.

  The material supply unit 10 melts the glass material and supplies the molten glass to the pressure forming unit 30. The material supply unit 10 includes a continuous melting furnace 11, a nozzle unit 12, and an outflow pipe 13.

  The continuous melting furnace 11 melts a glass material and stores molten glass. The nozzle unit 12 introduces the molten glass stored in the continuous melting furnace 11 into the outflow pipe 13. The outflow pipe 13 has an outlet at the lower end thereof, and allows the molten glass stream 70 to continuously flow out vertically downward from the outlet.

  The cutting unit 20 adjusts the amount of molten glass supplied from the material supply unit 10 to the pressure forming unit 30 to an appropriate amount. The cutting unit 20 includes a cutter 21 as a cutting mechanism and a cutter driving mechanism 22.

  The cutter 21 cuts the molten glass flow 70 flowing out from the outflow pipe 13 and separates the cut portion from the molten glass flow 70. The cutter 21 is configured by a pair of planar shear blades, and the pair of shear blades are abutted below the outflow pipe 13 to cut the molten glass flow 70. The cutter driving mechanism 22 drives the cutter 21. The cutter driving mechanism 22 is not particularly limited as long as it is a driving mechanism capable of cutting the cutter 21. 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 30 press-molds the glass material supplied from the material supply unit 10 using the mold 36. The pressure molding unit 30 includes a lower mold 31 and an upper mold 32 that constitute a mold 36, a lower mold drive mechanism 33, and an upper mold drive mechanism 34.

  The lower mold 31 receives the glass material supplied by the material supply unit 10 during a dropping step described later. The upper mold 32 is disposed so as to face the lower mold 31 during a pressure molding process described later. The lower mold 31 is disposed vertically below the upper mold 32.

  Examples of the material for forming the mold 36 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 mold 31 and the upper mold 32 may be made of the same material, or may be made of different materials.

  The surface of the mold 36 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 36 is configured to be heated to a predetermined temperature by a heating means (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 33 moves the lower mold 31 in the DR1 direction (horizontal direction) indicated by an arrow in FIGS. As a result, the lower mold 31 receives a glass material dropped from the material supply unit 10 (dropping position P1), and a position facing the upper mold 32 for molding the received glass material (molding). Position P2), positions for cooling the glass molded product (cooling positions P3 and P4), positions for taking out the glass molded product (takeout position P5), and positions for cleaning the surface of the lower mold 31 ( Move to and from the cleaning position P6). In addition, the moving direction of the lower mold | type 31 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 33 is not particularly limited as long as it is a drive mechanism capable of moving the lower mold 31. 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 33 includes a turntable 39 and a motor (not shown) that drives the turntable 39 to rotate.

  The upper mold drive mechanism 34 moves the upper mold 32 in the DR2 direction (vertical direction) indicated by an arrow in FIG. As a result, the upper die 32 reciprocates between a vertically upper position and a vertically lower position, and the upper die 32 and the lower die 31 approach and separate from each other. Of these, the vertically upper position is a position where the upper mold 32 waits before the glass material is pressure-molded, and the vertically lower position of these is the pressure molding of the glass material together with the lower mold 31. Position. The upper mold drive mechanism 34 is not particularly limited as long as it is a drive mechanism capable of moving the upper mold 32. 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.

  The mold release unit 40 takes out the glass molded product obtained by the pressure molding unit 30 from the mold 36. The release part 40 has a suction device 41. The suction device 41 is provided so as to face the lower mold 31 moved to the take-out position P5. As the suction device 41, for example, a known means using vacuum suction is used.

  The cleaning unit 50 cleans the surface of the lower mold 31 by suction in a state where the lower mold 31 and the upper mold 32 are separated from each other. The cleaning unit 50 cleans the surface of the lower mold 31 arranged at the cleaning position P6 by suction. The cleaning unit 50 is provided as a suction device that sucks the surface of the lower mold 31.

  The cleaning unit 50 includes a suction nozzle 51, a suction nozzle drive mechanism 52, and a suction unit 53.

  The suction nozzle 51 is provided to face the lower mold 31 and sucks glass waste remaining on the surface of the lower mold 31. The suction nozzle 51 has an opening 51a that faces the surface of the lower mold 31 and sucks glass dust together with the surrounding air. The suction port 51a opens on the surface of the lower mold 31 to be cleaned. The opening shape of the suction port 51a is not particularly limited. For example, the suction port 51a has a slit shape that is elongated in one direction. The suction unit 53 includes a negative pressure generation source for sucking glass waste through the suction nozzle 51 and a glass waste recovery unit for recovering the sucked glass waste.

  The suction nozzle drive mechanism 52 moves the suction nozzle 51 so that the suction port 51 a is scanned on the surface of the lower mold 31. In the present embodiment, the suction port 51a of the suction nozzle 51 is scanned on the surface of the lower mold 31 in the DR3 direction (horizontal direction) indicated by the arrow in FIG. The direction in which the suction port 51a is scanned on the surface of the lower mold 31 is not particularly limited, and may be, for example, a linear motion direction or a turning direction. The suction nozzle drive mechanism 52 is not particularly limited as long as the suction nozzle 51 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. By using the suction nozzle drive mechanism 52 as described above, the entire surface of the lower mold 31 is scanned by the suction port 51a of the suction nozzle 51, thereby reliably collecting glass scraps in a short tact time of, for example, 1 to 2 seconds. be able to.

  The control unit 60 controls operations of various mechanisms of the glass molded product manufacturing apparatus 100. More specifically, the operations of the cutter drive mechanism 22, the lower mold drive mechanism 33, the upper mold drive mechanism 34, the suction device 41, the suction nozzle drive mechanism 52, and the suction unit 53 are controlled. The control unit 60 cuts the molten glass flow 70 by the cutter 21, moves the lower mold 31, moves the upper mold 32, moves the suction device 41, moves the suction nozzle 51, and sucks A series of sequences related to the manufacture of the glass molded product, such as the operation timing of the unit 53, is controlled.

  The glass molded product manufactured using the glass molded product manufacturing apparatus 100 in FIG. 1 described above and the glass molded product manufactured by the glass molded product manufacturing method in the present embodiment described later are non-circular. Has a plan view. 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).

  As an example of the glass molded article, a cover glass included in a smartphone can be given. The cover glass is typically formed in a flat plate shape having a substantially rectangular plan view. The cover glass is not limited to a substantially rectangular plan view, and for example, the cover glass may have a shape in which a rectangular corner portion 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.

  FIG. 3 is a flowchart showing a method for manufacturing a glass molded product in the embodiment of the present invention. 4 to 14 are diagrams showing steps of a method for manufacturing a glass molded product according to the embodiment of the present invention. Then, the manufacturing method of the glass molded product in embodiment of this invention is demonstrated.

  The manufacturing method of the glass molded product in this Embodiment is based on what is called a direct press method, and is suitably implemented using the manufacturing apparatus 100 of the glass molded product in this Embodiment mentioned above. Moreover, the manufacturing method of the glass molded product in this Embodiment manufactures a several glass molded product sequentially by repeating the series of processes mentioned later.

  Referring to FIG. 1, in the method for manufacturing a glass molded product in the present embodiment, mold 36 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 product.

  Generally, when the temperature of the mold 36 is too low, it becomes difficult to form a highly accurate transfer surface on a glass molded product. On the other hand, if the temperature of the mold 36 is made excessively higher than necessary, the fusion between the mold 36 and the molten glass is likely to occur, or the life of the mold 36 may be shortened. Therefore, it is not preferable.

  For example, the temperature of the mold 36 is set in the range of (Tg−100) [° C.] to (Tg + 100) [° C.] with respect to the glass transition point 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 36, and the type of protective film. The heating temperatures of the molds constituting the mold 36 may be the same temperature or different temperatures.

  In the method for manufacturing a glass molded product in the present embodiment, after the mold 36 is heated to a predetermined temperature, the molten glass in a high temperature state is pressure-molded using the mold 36. In this case, a series of steps to be described later can be performed while keeping the temperature of the mold 36 constant. Furthermore, a plurality of glass molded products can be sequentially manufactured while keeping the temperature of the mold 36 constant. Therefore, since it is not necessary to repeat heating and cooling of the mold 36 every time one glass molded product is manufactured, a plurality of glass molded products can be manufactured efficiently in a very short time.

  Here, keeping the temperature of the mold 36 constant means that the target set temperature in the temperature control for heating the mold 36 is kept constant. Therefore, it is not intended to prevent even the temperature fluctuation of the mold 36 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 FIGS. 3 and 4, first, lower die 31 is moved to dropping position P1 (see FIGS. 1 and 2) (S101). As a result of detecting the current position of the lower mold 31, if the lower mold 31 is already arranged at the dropping position P <b> 1, the lower mold 31 is not moved. On the other hand, as a result of detecting the current position of the lower mold 31, when the lower mold 31 is arranged at a position other than the dropping position P 1, the lower mold drive mechanism 33 is operated by a command from the control unit 60, and the lower mold 31 is moved to the dropping position P1.

  Next, the molten glass flow 70 is cut (S102). The glass material stored in the continuous melting furnace 11 in a molten state flows out of the continuous melting furnace 11 through the nozzle portion 12 and falls in a liquid line form as a molten glass flow 70 from the outflow pipe 13 by its own weight. . The molten glass flow 70 flowing out from the outflow pipe 13 is cut by the cutter 21 to obtain a glass material 71 having a drop-like shape. The glass material 71 falls toward the lower mold 31.

  With reference to FIG. 3 and FIG. 5, the high-temperature glass raw material 71 of the fuse | melted state is dripped at the lower mold | type 31 (S103). The glass material 71 cut and dropped by the cutter 21 is collected and received on the lower mold 31. The glass material 71 supplied to the lower mold 31 spreads wet on the mold surface 31a of the lower mold 31 provided to face the upper mold 32 during a pressure molding process described later. The temperature of the glass material 71 dropped on the lower mold 31 is, for example, in the range of 800 ° C. or higher and 900 ° C. or lower. The dropping process of the glass material 71 is completed by the S102 process and the S103 process.

  Referring to FIGS. 3 and 6, next, lower die 31 is moved to molding position P2 (see FIGS. 1 and 2) (S104). The lower mold drive mechanism 33 is actuated by a command from the control unit 60 to move the lower mold 31 in the horizontal direction (DR1 direction shown in FIGS. 1 and 2). Accordingly, the lower mold 31 is moved to the molding position P2, and the lower mold 31 and the upper mold 32 are disposed to face each other at a distance.

  FIG. 8 shows a cross section of a process of the method for producing a glass molded product along the line VIII-VIII in FIG. FIG. 9 shows a cross-section of the process of the method for manufacturing a glass molded product along the line XI-XI in FIG. 7, and the opening surface of the recess 35 formed in the upper mold 32 is represented by a two-dot chain line. ing.

  Referring to FIGS. 3 and 7 to 9, next, glass material 71 is pressure-formed by upper die 32 and lower die 31 by lowering upper die 32 (S <b> 105). The upper mold drive mechanism 34 is actuated by a command from the controller 60, and the upper mold 32 is lowered toward the lower mold 31. The glass material 71 is pressed while being pressed between the mold surface 31 a of the lower mold 31 and the mold surface 32 a of the upper mold 32.

  In the present embodiment, the mold surface 31a of the lower mold 31 has a shape extending in a planar shape, while the mold surface 32a of the upper mold 32 is formed with a recess 35 for molding the outer shape of the glass molded product. ing. The recess 35 has an opening surface having a shape corresponding to a non-circular plan view of the glass molded product on the mold surface 32a. In FIG. 9, the case where the recessed part 35 has a rectangular-shaped opening surface is shown as an example supposing manufacture of the cover glass which has a rectangular planar view.

  As the upper mold 32 moves closer to the lower mold 31, the glass material 71 is deformed so as to fill the recess 35, and further from the recess 35 to the space between the mold surface 31a and the mold surface 32a. Deforms to enter. Thereby, the glass raw material 71 is pressure-molded and the glass molded product 72 is obtained.

  The temperature of the glass material 71 at the start of the pressure molding process is preferably set to (Tg + 50) ° C. or higher and (Tg + 200) ° C. or lower. For example, when Tg is 540 ° C., the temperature of the glass material 71 immediately before pressing may be 680 ° C. The temperature of the glass material 71 can be measured by a radiation thermometer, for example. In order to obtain such a temperature setting, the glass transition temperature is set to Tg, the temperature of the upper mold 32 is set to (Tg-60) ° C. or higher and (Tg-20) ° C. or lower, and the temperature of the lower mold 31 is set to ( Tg-80) ° C. or higher and (Tg-10) ° C. or lower may be set. For example, when Tg is 540 ° C., the temperature of the upper mold 32 may be 500 ° C., and the temperature of the lower mold 31 may be 520 ° C. Further, at the time of pressurization, for example, a pressure of approximately 2 tons is applied to the glass material 71 for approximately 10 seconds.

  Referring to FIGS. 3 and 10, next, upper mold 32 is moved up (S106). At this time, the upper mold 32 is separated from the glass molded product 72, and the glass molded product 72 remains on the lower mold 31.

  The temperature of the glass molded product 72 when the upper mold 32 starts to move for ascending operation is preferably set to (Tg−30) ° C. or higher and (Tg + 100) ° C. or lower. For example, when Tg is 540 ° C., the temperature of the glass molded product 72 at the start of the ascending operation of the upper mold 32 may be set to 510 ° C. or more and 640 ° C. or less. When the said temperature becomes lower than (Tg-30) degreeC, the amount of heat shrinks of the glass molded product 72 becomes large, and defects such as cracks are likely to occur. On the other hand, when the temperature is higher than (Tg + 100) ° C., there is a concern that the surface shape of the glass molded product 72 may be collapsed or a good transferability may not be obtained with the ascending operation.

  3 and 11, next, lower die 31 is moved to take-out position P5 (see FIGS. 1 and 2) via cooling positions P3 and P4 (see FIGS. 1 and 2). Move (S107). The lower mold 31 is moved below the upper mold 32 by operating the lower mold drive mechanism 33 in accordance with a command from the control unit 60 and moving the lower mold 31 in the horizontal direction (DR1 direction shown in FIGS. 1 and 2). Is moved from the molding position P2 positioned to the take-out position P5 not facing the upper mold 32.

  Next, the glass molded product 72 is taken out from the lower mold 31 and collected (S108). The taking-out operation of the glass molded product 72 is performed using, for example, a known release device such as a suction device using vacuum suction. Thereby, the glass molded product 72 is released from the lower mold 31. By subjecting the glass molded product 72 released from the lower mold 31 to an appropriate cutting process and / or polishing process, a final shape of a glass product such as a cover glass is obtained.

  FIG. 13 shows steps of a method for manufacturing a glass molded product along the line XIII-XIII in FIG. 12, and FIG. 14 shows a method for manufacturing a glass molded product along the line XIV-XIV in FIG. These steps are shown.

  With reference to FIGS. 3 and 12 to 14, next, the lower mold 31 is moved to the cleaning position P6 (see FIGS. 1 and 2) (S109). The lower mold drive mechanism 33 is actuated by a command from the control unit 60 to move the lower mold 31 in the horizontal direction (DR1 direction shown in FIGS. 1 and 2).

  Next, the surface of the lower mold 31 is cleaned (S110). Specifically, by operating the suction unit 53, a negative pressure is generated at the suction port 51 a of the suction nozzle 51. By operating the suction nozzle drive mechanism 52, the suction port 51 a of the suction nozzle 51 is scanned on the surface of the lower mold 31.

  In the present embodiment, the suction nozzle 51 is fixed to a piston rod of an air (hydraulic) cylinder that is the suction nozzle drive mechanism 52 via an angle 57. The suction port 51a has a slit shape that is elongated in one direction. The suction port 51 a is opened facing the mold surface 31 a of the lower mold 31. The suction nozzle 51 is provided such that a suction port 51a having a slit shape extends along one side of the mold surface 31a having a rectangular plan view.

  The mold surface 31a of the lower mold 31 is cleaned by reciprocating the suction nozzle 51 along a direction orthogonal to the direction in which the suction port 51a extends in a slit shape. At this time, it is preferable to clean the entire surface of the mold surface 31a by moving the suction nozzle 51 from one end of the mold surface 31a to the other end. The step of cleaning the surface of the lower die 31 preferably sucks the position facing the upper die 32 during the pressure forming step. The process of cleaning the surface of the lower mold 31 is preferably performed on all of the lower mold 31 that has undergone the pressure molding process.

  Depending on the supply amount of the glass material 71 to the lower mold 31 and the conditions at the time of pressure molding, burrs are generated in the glass molded product 72, and glass scraps remain on the surface of the lower mold 31 after the glass molded product 72 is released. It becomes. On the other hand, in this Embodiment, the glass waste remaining on the surface of the lower mold | type 31 can be removed by cleaning the mold surface 31a of the lower mold | type 31 after mold release of the glass molded product 72. FIG. At this time, since the mold surface 31a of the lower mold 31 is cleaned by suction, the glass waste can be reliably recovered without being scattered in the manufacturing space of the glass molded product.

  FIG. 15 is an enlarged cross-sectional view of a range surrounded by a two-dot chain line XV in FIG. Referring to FIGS. 9 and 15, it is preferable that the peripheral edge portion 81 of the opening surface of the recess 35 has a sharp edge shape. According to such a configuration, it becomes difficult for the glass material 71 deformed in the recess 35 to go to the outside of the recess 35 at the time of pressure molding, so that the glass material 71 can be spread to every corner of the recess 35. . Thereby, the shape of the recessed part 35 can be accurately transferred to the glass molded product 72.

  In addition, even if it is the peripheral part 81 by which the thread chamfering of C0.2 or less was processed, it can be said that the peripheral part 81 makes a sharp edge shape.

  On the other hand, when the peripheral part 81 of the opening surface of the recessed part 35 is made into a sharp edge shape, the movement of the glass raw material 71 stagnates in the peripheral part 81 at the time of pressure forming, and a forming pressure rises locally. For this reason, in the upper mold 32 moved upward after the pressure molding step, glass dust is generated around the peripheral edge portion 81, and a phenomenon occurs in which the glass waste falls on the lower mold 31. In particular, such a phenomenon is likely to occur at the corner portions 81p of the peripheral edge portion 81 (four corners of the peripheral edge portion 81 having a rectangular shape) where the molding pressure becomes maximum.

  In the present embodiment, by cleaning the mold surface 31 a of the lower mold 31, the glass dust generated due to the sharp edge shape of the peripheral edge portion 81 can also be removed.

  In addition, the occurrence of burrs is also noticeable at the peripheral edge of the glass material 71 deformed between the upper mold 32 and the lower mold 31 at the time of pressure molding (the peripheral edge 82 of the glass molded product 72 in FIG. 15). For this reason, it is preferable to suck the position facing the peripheral edge of the glass material 71 during the process of cleaning the surface of the lower mold 31.

  According to the glass molded product manufacturing apparatus 100 and the glass molded product manufacturing method according to the embodiment of the present invention configured as described above, the lower mold 31 is obtained by a cleaning process by suction after the glass molded product 72 is released. As well as removing glass debris from the surface, the removed glass debris can be reliably recovered from the manufacturing space of the glass molded product. Thereby, it is possible to prevent glass waste from being mixed into the glass material 71 in the subsequent pressure forming step, and to prevent the appearance of the glass molded product 72 from being defective. Moreover, it can prevent that the surface of the lower mold | type 31 and the upper mold | type 32 arises at the time of pressure molding resulting from the glass waste which remains on the surface of the lower mold | type 31. FIG.

  In the present embodiment, the case where a pair of lower molds and upper molds are used as molds for press-molding a glass material has been described as an example, but the number of molds is limited to this. Instead, pressure molding may be performed using three or more molds.

  Moreover, in this Embodiment, although the cover glass with which a smart phone was comprised was illustrated as a glass molded article manufactured by applying this invention, it is not limited to this, For example, other than a tablet terminal etc. The present invention may be applied to the manufacture of a cover glass of the display device and the manufacture of an exterior cover of an electronic device such as a mobile computer or a digital camera.

  FIG. 16 is a table showing the appearance defect rate due to foreign matters in glass molded products in Examples and Comparative Examples.

  Referring to FIG. 16, in this example, in the example in which the cleaning process by suction was performed, 500 glass molded products were manufactured, and the rate at which defects occurred in the appearance of the obtained glass molded products was confirmed. . Further, for comparison, in Comparative Example 1 in which the cleaning process is not performed and in Comparative Example 2 in which the cleaning process by air blow is performed, the ratio of occurrence of defects in the appearance of the glass molded product was also confirmed.

  As shown in FIG. 16, in Comparative Example 1 in which the cleaning process was not performed, the defect rate of the appearance of the glass molded product was high due to the mixing of glass debris. Moreover, also in the comparative example 2 which implemented the cleaning process by an air blow, the external appearance defect of the glass molded product was not fully prevented by the phenomenon that glass waste moves on the lower mold | type 31 of another position. On the other hand, according to the Example which performed the cleaning process by suction, the external appearance defect rate of the glass molded product was able to be improved significantly.

  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 used for manufacturing a glass molded article using a direct press method.

  DESCRIPTION OF SYMBOLS 10 Material supply part, 11 Continuous melting furnace, 12 Nozzle part, 13 Outflow pipe, 20 Cutting part, 21 Cutter, 22 Cutter drive mechanism, 30 Press molding part, 31 Lower mold, 31a, 32a Mold surface, 32 Upper mold, 33 Lower mold drive mechanism, 34 Upper mold drive mechanism, 35 recess, 36 mold, 39 turntable, 40 mold release section, 41 suction device, 50 cleaning section, 51 suction nozzle, 51a suction port, 52 suction nozzle drive mechanism, 53 suction part, 57 angle, 60 control part, 70 molten glass flow, 71 glass material, 72 glass molded product, 81 peripheral part, 81p corner part, 82 peripheral part, 100 manufacturing apparatus of glass molded product.

Claims (6)

A method of producing a glass molded product having a non-circular plan view by a direct press method,
Supplying a molten glass material to the first mold;
A step of pressure-molding the glass material using the first mold supplied with the glass material and a second mold disposed opposite to the first mold;
Separating the first mold and the second mold and releasing the glass molded product;
And a step of cleaning the surface of the first mold by suction after the step of releasing the glass molded product. The second mold has an opening surface having a shape corresponding to a non-circular plan view of a glass molded product when viewed from the first mold side, and is a step of pressure-molding the glass material. Sometimes a recess filled with glass material is formed,
The said recessed part is a manufacturing method of the glass molded product of Claim 1 which makes a sharp edge shape in the peripheral part of the said opening surface.   The glass molded product according to claim 1, wherein the step of cleaning the surface of the first mold includes a step of sucking a position facing the second mold during the step of pressure-molding the glass material. Manufacturing method.   The step of cleaning the surface of the first mold sucks a position facing the peripheral edge of the glass material deformed between the first mold and the second mold during the pressure molding of the glass material. The manufacturing method of the glass molded product of any one of Claim 1 to 3 including a process. An apparatus for producing a glass molded product having a non-circular plan view by a direct press method,
A first mold to which a molten glass material is supplied;
A second mold that is disposed opposite to the first mold and press-molds a glass material together with the first mold;
An apparatus for manufacturing a glass molded product, comprising: a cleaning unit that cleans the surface of the first mold by suction in a state where the first mold and the second mold are separated.   The cleaning unit moves the suction nozzle so that the suction nozzle has a suction port that opens facing the surface of the first mold, and the suction port is scanned on the surface of the first mold. The manufacturing apparatus of the glass molded product of Claim 5 containing a suction nozzle drive mechanism.

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