JP6622545B2 - Glass forming apparatus and glass forming method - Google Patents

Description

  The present invention relates to a glass forming apparatus and a glass forming method for pressing a glass material by changing a pressing force.

  Conventionally, as this type of technology, for example, one described in Patent Document 1 shown below is known. This Patent Document 1 discloses an optical element manufacturing apparatus that molds an optical element material while reducing the pressure to zero or more during pressurization when the optical element material disposed in a mold is pressure-molded. Is described. In this manufacturing apparatus, the optical element molding temperature when the applied pressure is changed is maintained at a constant molding temperature at which the optical element material can be pressure-molded.

JP-A-8-259240

  In the above-described conventional technology, the pressing force is changed during pressurization during press molding, but the optical element temperature is not changed and is maintained at a constant molding temperature. That is, at the time of pressure molding, the highest pressure among the fluctuating pressures is finally applied to the optical element material at the molding temperature that is kept constant.

  For this reason, when the mold and the softened optical element material are pressed with a high pressure, the fine particles of the mold material adhere to the optical element material, or minute irregularities on the mold surface are transferred to the optical element material. There was a problem that it was easy. As a result, the quality of the optical element molded product is lowered.

  An object of the present invention is to suppress the deterioration of the quality of a glass molded product by suppressing the fine particles of the mold material from adhering to the optical element material or transferring the minute irregularities on the mold surface to the optical element material. It is to provide a forming apparatus and a glass forming method.

The glass molding apparatus of the present invention includes a molding part that press-molds a glass material made of a flat glass plate arranged in a mold constituted by an upper mold and a lower mold, and the molding part is the glass A pre-forming step of pre-forming the material at a first temperature; and a main forming step of main-forming the glass material at a second temperature, wherein the pre-forming step includes the glass through the mold. A heating step of heating the material until it reaches a first molding temperature; and the mold with a first pressing force that forms a predetermined gap between at least one of the upper mold and the lower mold and the glass material. A first pressing step of pressing, wherein the main forming step is a step of cooling the glass material through the mold until the glass material reaches a second molding temperature, and pressing the mold with a second pressing force. A second pressing step, wherein the second molding temperature is the second pressing temperature. Lower than the molding temperature, the second pressing force, being greater than said first pressing force.

  The molding part preferably has a cooling step for cooling the glass material arranged in the mold.

The mold is preferably made of any one of a carbon material, a ceramic material, and a cemented carbide material .

  Preferably, the forming part is formed by forming the glass material of a flat glass plate, the middle part in the short side direction of the glass material is flat, and the end part in the short side direction of the glass material is formed in a curved shape. The formed glass molded product is molded.

The glass molding method of the present invention includes a molding part that press-molds a glass material made of a flat glass plate arranged in a mold composed of an upper mold and a lower mold, and the molding part includes the glass A pre-forming step of pre-forming the material at a first temperature; and a main forming step of performing the glass material at a second temperature after the pre-forming step, and in the pre-forming step, After performing a heating step of heating the glass material to the first molding temperature through the mold, a predetermined gap is provided between at least one of the upper mold and the lower mold and the glass material. A first pressing step of pressing the mold with a first pressing force to be configured is performed, and in the main molding step performed after the pre-molding step, the glass material is placed above the first molding temperature through the mold. A cooling process was performed to cool until a low second molding temperature was reached. , And carrying out a second pressing step of pressing the mold at a second pressing force greater than the first pressing force.

  According to the glass molding apparatus or the glass molding method of the present invention, it is possible to suppress the fine particles of the mold material from adhering to the optical element material or the transfer of minute irregularities on the mold surface to the optical element material. . Thereby, the glass shaping | molding apparatus or glass shaping | molding method of this invention can avoid the quality fall of a glass molded product.

It is a figure which shows the structure of the glass forming apparatus which concerns on embodiment of this invention. It is a flowchart which shows the procedure of the formation process which the glass forming apparatus which concerns on embodiment of this invention performs. It is an external view which shows an example of the glass molded product which the glass forming apparatus which concerns on embodiment of this invention manufactures. It is the top view which looked at the metal mold | die used with the glass forming apparatus which concerns on embodiment of this invention from the top. It is sectional drawing which follows the IV-IV line of FIG. It is process sectional drawing which shows one shaping | molding process which the glass forming apparatus which concerns on embodiment of this invention performs. It is other process sectional drawing which shows one shaping | molding process which the glass forming apparatus which concerns on embodiment of this invention performs. It is other process sectional drawing which shows one shaping | molding process which the glass forming apparatus which concerns on embodiment of this invention performs.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(Embodiment)
With reference to FIG. 1, the structure of the glass forming apparatus which concerns on embodiment of this invention is demonstrated.

  In FIG. 1, the glass forming apparatus 1 includes a forming unit 11 and a control unit 12.

  The molding unit 11 includes a mold composed of an upper mold and a lower mold, and heats, presses, and cools the mold in a state where a glass material is disposed between the upper mold and the lower mold. A glass material is molded to form a glass molded product.

  The molding unit 11 performs a molding process including a pre-molding process, a main molding process, and a cooling process according to the flowchart shown in FIG.

  In FIG. 2, the shaping | molding part 11 performs a pre-molding process in step S1. The molding unit 11 first heats the mold in a state where the glass material is disposed between the upper mold and the lower mold, and heats the mold until the first molding temperature at which the glass material can be molded is reached.

  The first molding temperature is a temperature for deforming the glass material, and varies depending on the glass type of the glass material. For example, in the case of chemically strengthened glass, a range of 700 ° C. to 800 ° C. is preferable, and 750 ° C. The degree is further preferred. Therefore, here, the first molding temperature is a high temperature of about 750 ° C.

  When the glass material reaches the first molding temperature, the molding unit 11 presses the mold with a first pressing force that forms a predetermined gap between the lower mold and the glass material, as will be described later. The first pressing force is set to a pressing force that is lower than the pressing force for pressing the glass material when the glass material is pressed to perform the main forming in the main forming process described later.

  The first pressing force varies depending on the type of glass of the glass material. For example, in the case of chemically strengthened glass, the range is preferably 0.5 (kN) to 5 (kN), and more preferably about 1 (kN). . The first pressing force is a pressing force lower than a second pressing force described later. Therefore, here, the first pressing force is a relatively low pressing force of about 1 (kN).

  Thus, the shaping | molding part 11 preforms a glass raw material by performing a pre-molding process.

  Subsequently, the molding unit 11 performs the main molding process following the pre-molding process after the pre-molding process is completed in Step S2.

  First, after the pre-molding step is completed, the molding unit 11 reduces the temperature of the mold and cools the glass material to a second molding temperature at which the glass material can be molded.

  The second molding temperature varies depending on the type of glass of the glass material. For example, in the case of chemically strengthened glass, a range of 600 ° C. to 700 ° C. is preferable, and about 650 ° C. is more preferable. Accordingly, here, the second molding temperature is set to an intermediate temperature of about 650 ° C.

  When the glass material reaches the second molding temperature, the molding unit 11 presses the mold with the second pressing force. Thereby, the shaping | molding part 11 carries out the main shaping | molding of a glass raw material so that a glass raw material may become a shape of a glass molded product. Therefore, the second pressing force is a pressing force required when the glass material is fully formed, and is set to a value higher than the first pressing force used when the glass material is pre-formed.

  For example, in the case of chemically strengthened glass, the second pressing force is preferably in the range of 5 (kN) to 15 (kN), and more preferably about 10 (kN). Therefore, here, the second pressing force is a relatively high pressing force of about 10 (kN).

  In this way, the forming unit 11 performs the main forming process to perform the main forming of the glass material.

  Subsequently, in step S3, the molding unit 11 performs a cooling process following the main molding process after the main molding process is completed.

  The molding unit 11 cools the molded glass material to a predetermined temperature in a state where the molded glass material is placed in the mold.

  Note that the pre-molding step and the main molding step can be performed at the same molding station or at different molding stations. When the same molding station is used, the pre-molding step and the main molding step are performed at one place without moving the mold on which the glass material is arranged.

  By performing the pre-molding process and the main molding process at different stations, the molding unit 11 can easily perform temperature management of the pre-molding process and the main molding process.

  On the other hand, when it is performed at a different station, for example, the pre-molding step is performed at the pre-molding station, and the main molding step is performed at the main molding station which is a molding place different from the pre-molding station. The mold on which the glass material is arranged is transferred from the pre-forming station to the main forming station when the pre-forming step is completed.

  The control unit 12 functions as a control center that controls the operation of the glass forming apparatus 1. The control unit 12 is configured by, for example, a microcomputer including a CPU that controls various operation processes based on a program, a storage unit, and the like. The control unit 12 stores a program for executing a control sequence for controlling the forming process of the glass forming apparatus 1 in the storage unit.

  The control unit 12 executes the program stored in the storage unit, and comprehensively manages and controls all operations performed in the glass forming apparatus 1 including the forming process performed by the forming unit 11.

  The control unit 12 controls and manages the first molding temperature and the first pressing force in the pre-molding process performed by the molding unit 11. The control unit 12 controls and manages the second molding temperature and the second pressing force in the main molding process performed by the molding unit 11.

  An example of a glass molded product molded by the glass molding apparatus 1 having the above configuration is shown in FIG. As shown in FIG. 3, the glass molded product 2 has three regions extending in the long side direction in the short side direction of the glass molded product 2. The two are constituted by end portions 22 having curved shapes at both ends of the intermediate portion 21. The glass molded product 2 is used as a cover glass that covers a display screen of a mobile terminal such as a smartphone or a tablet computer.

  A glass molded product 2 shown in FIG. 3 is molded using, for example, a mold shown in FIGS. 4 and 5. 4 is a plan view of the mold as viewed from above, and FIG. 5 is a cross-sectional view taken along line IV-IV in FIG.

  As shown in FIGS. 4 and 5, the mold 3 includes an upper mold 31, a lower mold 32, and a sleeve 33. The mold 3 is formed by bending the end 22 in the short side direction of a flat glass plate 34 serving as a glass material into a curved shape.

  The upper mold 31 includes a first upper mold 35 and a second upper mold 36.

  The first upper mold 35 is formed in a rectangular parallelepiped shape, and sandwiches the intermediate portion 21 in the short side direction of the glass plate 34 in cooperation with the lower mold. The first upper mold 35 molds the intermediate portion 21 in the short side direction of the glass plate 34 flatly.

  The second upper mold 36 sandwiches the end 22 in the short side direction of the glass plate 34 in cooperation with the lower mold 32. The second upper mold 36 is provided with a curved curved surface 37 at the lower end. The curved curved surface 37 is provided to abut against and press the end portion 22 in the short side direction of the glass plate 34 and to curve and shape the end portion 22 in the short side direction of the glass plate 34 in a curved shape. ing.

  The sleeve 33 is formed in a rectangular frame shape, and performs positioning of the second upper mold 36 and guide of the second upper mold 36. The second upper mold 36 is inserted into the sleeve 33 from the initial state, and moves freely in a vertical direction with respect to the lower mold 32 while being engaged and guided by the sleeve 33. The initial state is a state in which the glass plate 34 is placed on the lower mold 32 and the upper mold 31 is separated from the lower mold 32 above the lower mold 32.

  The sleeve 33 is provided with a guide surface 38 that is inclined inward of the upper part. By providing the guide surface 38 on the sleeve 33, the second upper mold 36 is guided by the guide surface 38 and smoothly inserted into the sleeve 33. Further, since the second upper mold 36 is smoothly inserted into the sleeve 33 by the guide surface 38, the distance between the second upper mold 36 and the sleeve 33 can be reduced, and the second upper mold 36 can be reduced. The position of 36 becomes difficult to shift.

  The lower mold 32 is formed with a molding portion 39 for molding the glass plate 34 into a predetermined shape. A curved portion 40 is formed at both ends in the short side direction of the forming portion 39 in order to bend the end portion 22 in the short side direction of the glass plate 34 in a curved shape in cooperation with the second upper mold 36. Has been.

  The mold 3 can be made of a material that has excellent heat resistance and can maintain strength even at high temperatures, for example, a carbon material, a ceramic material, or a cemented carbide (tungsten carbide) material.

  Next, an example of a procedure in which the glass forming apparatus 1 forms the glass plate 34 using the mold 3 to manufacture the glass molded product 2 will be described with reference to the cross-sectional views of FIGS.

  First, the molding unit 11 performs a pre-molding process.

  In the pre-molding step, the glass plate 34 is placed on the lower mold 32 as shown in FIG.

  Subsequently, the first upper mold 35 is lowered, the first upper mold 35 is brought into contact with the glass plate 34, the glass plate 34 is pressed from above by the weight of the first upper mold 35, and the glass plate 34 is lowered. Clamp in cooperation with the mold 32. At this time, the first upper mold 35 does not press the glass plate 34.

  Subsequently, as shown in FIG. 7, first, the glass plate 34 can be formed by heating the mold 3 in a state where the first upper mold 35 and the lower mold 32 are sandwiched together. Until the first molding temperature is reached. The first molding temperature is as high as about 750 ° C. described above.

  When the glass plate 34 reaches the first molding temperature, the second upper die 36 is lowered, the second upper die 36 is brought into contact with the glass plate 34, and the glass plate 34 is sandwiched in cooperation with the lower die 32. . In the state where the glass plate 34 is sandwiched between the upper mold 31 and the lower mold 32 of the first upper mold 35 and the second upper mold 36 in cooperation, the first upper mold 35 and the second upper mold 35 and the second upper mold 36 are sandwiched. The upper die 36 is pressed with the first pressing force described above to temporarily press the glass plate 34.

  When the second upper mold 36 presses the end 22 in the short side direction of the glass plate 34, an upward force acts on the intermediate portion 21 in the short side direction of the glass plate 34, and the glass plate 34 and the first upper metal The mold 35 is slightly lifted upward. Thereby, a gap 41 is formed between the lower mold 32 and the glass plate 34. The width of the gap 41 is, for example, about 0.5 (mm).

  Thus, the gap 41 is formed between the lower mold 32 and the glass plate 34. As a result, when the lower mold 32 is made of a carbon material that is inexpensive and easy to use, even if the glass plate 34 is at a high temperature of 750 ° C., the carbon fine particles of the lower mold 32 are removed from the surface of the glass plate 34. It can suppress adhering to.

  In addition, when the lower mold 32 is made of the above-described material other than the carbon material, fine irregularities formed on the surface of the lower mold 32 that contacts the surface of the glass plate 34 are transferred to the surface of the glass plate 34. Can be suppressed.

  In this way, the pre-molding step is performed and the process ends.

  After the pre-molding process is completed, the molding unit 11 subsequently performs the main molding process.

  In the main forming step, as shown in FIG. 8, first, after the pre-forming step is completed, the temperature of the mold 3 is lowered and the glass plate 34 is cooled to a second forming temperature at which it can be formed. The second molding temperature is an intermediate temperature of about 650 ° C., which is lower than the first molding temperature.

  When the glass plate 34 reaches the second molding temperature, as shown in FIG. 8, the glass plate 34 is composed of a first upper mold 35 and a second upper mold 36, and an upper mold 31 and a lower mold. The first upper mold 35 and the second upper mold 36 are both pressed by the second pressing force in a state where the second upper mold 35 and the second upper mold 36 are sandwiched. At this time, the first upper mold 35 and the second upper mold 36 are pressed with a second pressing force that does not allow the gap 41 between the lower mold 32 and the glass plate 34. Thereby, the whole intermediate part 21 and the end part 22 of the short side direction of the glass plate 34 are fully pressed. Thereby, the flat glass plate 34 is shape | molded by the glass molded product 2 of the shape shown in FIG.

  In the main forming step, the glass plate 34 is lowered to the second forming temperature lower than the first forming temperature in the pre-forming step, so that the surface of the glass plate 34 is hardened compared to the state in the pre-forming step. . Thereby, when the lower mold 32 is made of, for example, a carbon material, even if the glass plate 34 is pressed with a second pressing force higher than the first pressing force, the carbon fine particles of the lower mold 32 are not reduced. It can suppress adhering to the surface.

  Further, when the lower mold 32 is made of the above-described other carbon material, fine irregularities formed on the surface of the lower mold 32 in contact with the surface of the glass plate 34 are transferred to the surface of the glass plate 34. Can be suppressed.

  In this way, the main molding process is performed and the process is completed.

  After the main molding process is completed, the molding unit 11 subsequently performs a cooling process.

  In the cooling step, the molded glass plate 34 is cooled in a state where the molded glass plate 34 is disposed in the mold 3 that is not pressed.

  Thereby, the molded glass plate 34 is cooled substantially uniformly as compared with the case where the glass plate 34 is cooled in a state where the glass plate 34 is taken out from the mold 3. As a result, in the glass plate 34, temperature unevenness at which the temperature of the glass plate 34 becomes nonuniform can be suppressed, and deformation of the glass molded product 2 can be prevented.

  After the cooling process is finished, the glass plate 34 cooled to a predetermined temperature is taken out from the mold 3 as the glass molded product 2, and a series of forming processes is finished.

  As described above, in the embodiment according to the present invention, the following effects can be obtained.

  The glass molding apparatus 1 according to this embodiment includes a molding unit 11 and a control unit 12 that press-mold a glass material disposed in a mold 3 including an upper mold 31 and a lower mold 32.

  The molding unit 11 includes a pre-molding step for pre-molding the glass material at a first temperature and a main molding step for main-molding the glass material at the second temperature.

  The control unit 12 controls the pre-molding process and the main molding process performed by the molding unit 11.

  The pre-molding step includes a heating step of heating the glass material through the mold 3 until the first molding temperature is reached, and a predetermined gap 41 between at least one of the upper mold 31 and the lower mold 32 and the glass material. And a first pressing step of pressing the mold with a first pressing force that constitutes.

  The main molding step includes a cooling step of cooling the glass material through the mold 3 until the second molding temperature is reached, and a second pressing step of pressing the mold 3 with the second pressing force.

  The second molding temperature is set lower than the first molding temperature, and the second pressing force is set higher than the first pressing force.

  By adopting the above configuration, the glass forming apparatus 1 forms a gap 41 between the lower mold 32 and the surface of the glass plate 34 in the pre-forming step. In the main molding step, molding is performed at a second molding temperature lower than the first molding temperature in the pre-molding step. Thereby, it is possible to suppress the fine particles of the material of the lower mold 32 from adhering to the surface of the glass plate 34 in the pre-molding step and the main molding step. In addition, in the pre-molding step and the main molding step, it is possible to suppress transfer of fine irregularities on the surface of the lower mold 32 to the surface of the glass plate 34. As a result, it is possible to avoid deterioration of the quality of the glass molded product.

  The molding part 11 of the glass molding apparatus 1 of this embodiment performs the cooling process which cools the glass plate 34 in the state which the glass plate 34 shape | molded by this shaping | molding has been arrange | positioned to the metal mold | die 3 after a main shaping | molding process.

  By adopting the above configuration, the glass forming apparatus 1 cools the formed glass plate 34 more uniformly than when the formed glass plate 34 is cooled in a state where the formed glass plate 34 is taken out from the mold 3. Is done. As a result, the molded glass plate 34 can suppress temperature unevenness at which the temperature of the molded glass plate 34 becomes non-uniform, and deformation of the glass molded product 2 can be prevented.

  The mold 3 used in the glass forming apparatus 1 of this embodiment is made of any one of a carbon material, a ceramic material, and a cemented carbide material.

  When the mold 3 is made of a carbon material, the glass forming apparatus 1 can suppress adhesion of carbon fine particles to the surface of the glass plate 34. Further, when the lower mold 32 is made of a ceramic material or a cemented carbide material, it is possible to suppress transfer of fine irregularities formed on the surface of the lower mold 32 to the surface of the glass plate 34. Can do.

  The forming part 11 of the glass forming apparatus 1 of this embodiment forms the glass material of the flat glass plate 34, the intermediate part 21 in the short side direction of the glass material is flat, and the end of the short side direction of the glass material The glass molded product 2 in which the portion 22 is formed in a curved shape is formed.

  By adopting the above configuration, the glass forming apparatus 1 can form a glass molded product 2 suitable for a cover glass that covers a display screen of a mobile terminal such as a smartphone or a tablet computer.

  The glass forming method of this embodiment includes a pre-forming step of pre-forming a glass material at a first temperature, and a main forming step of performing the main forming of the glass material at a second temperature after the pre-forming step. .

  In the pre-molding step, after performing a heating step of heating the glass material until it reaches the first molding temperature via the mold 3, a predetermined gap is provided between at least one of the upper mold 31 and the lower mold 32 and the glass material. A first pressing step of pressing the mold 3 with a first pressing force constituting the gap 41 is performed.

  In the main molding step performed after the pre-molding step, the glass material is cooled through the mold 3 until the second molding temperature is lower than the first molding temperature, and then higher than the first pressing force. A second pressing step of pressing the mold 3 with the second pressing force is performed.

  In the glass forming method of this embodiment, by adopting the above procedure, a gap 41 is formed between the lower mold 32 and the surface of the glass plate 34 in the pre-forming step. In the main molding step, molding is performed at a second molding temperature lower than the first molding temperature in the pre-molding step. Thereby, it is possible to suppress the fine particles of the material of the lower mold 32 from adhering to the surface of the glass plate 34 in the pre-molding step and the main molding step. In addition, in the pre-molding step and the main molding step, it is possible to suppress transfer of fine irregularities on the surface of the lower mold 32 to the surface of the glass plate 34. As a result, it is possible to avoid deterioration of the quality of the glass molded product.

  In addition, although the present Example gave and demonstrated the example which made the edge part 22 in the both ends of the short side direction of the glass molded product 2 curved, it made the edge part in the both ends of a long side direction curved. Good. Even in this case, the same effects as in the present embodiment can be obtained. Furthermore, the mold configuration may be configured upside down from the present embodiment. In this case, a gap is formed between the upper mold and the glass plate, and the same effect as in the present embodiment is achieved.

DESCRIPTION OF SYMBOLS 1 Glass molding apparatus 2 Glass molded product 3 Mold 11 Molding part 12 Control part 31 Upper mold 32 Lower mold 41 Crevice

Claims (5)

It has a molding part that press-molds a glass material made of a flat glass plate arranged in a mold composed of an upper mold and a lower mold,
The molded part is
A pre-forming step of pre-forming the glass material at a first temperature;
A main forming step of forming the glass material at a second temperature;
Have
The pre-molding step is
A heating step of heating the glass material to the first molding temperature through the mold;
A first pressing step of pressing the mold with a first pressing force constituting a predetermined gap between at least one of the upper mold and the lower mold and the glass material;
Including
The main forming step includes a cooling step of cooling the glass material to a second forming temperature through the mold,
A second pressing step of pressing the mold with a second pressing force;
Including
Furthermore, the second molding temperature is lower than the first molding temperature, and the second pressing force is higher than the first pressing force.   The said shaping | molding part has a cooling process which cools the said glass raw material arrange | positioned at the said metal mold | die, The glass shaping | molding apparatus of Claim 1 characterized by the above-mentioned. The glass molding apparatus according to claim 1 or 2, wherein the mold is made of any one of a carbon material, a ceramic material, and a cemented carbide material .   The molding part is formed by molding the glass material of a flat glass plate, the intermediate part in the short side direction of the glass material is flat, and the end part in the short side direction of the glass material is formed in a curved shape. The glass forming apparatus according to any one of claims 1 to 3, wherein a glass molded product is formed. It has a molding part that press-molds a glass material made of a flat glass plate arranged in a mold composed of an upper mold and a lower mold,
The molded part is
A pre-forming step of pre-forming the glass material at a first temperature;
A main forming step of performing the glass material at a second temperature after the pre-forming step,
In the pre-molding step, after performing a heating step of heating the glass material to the first molding temperature via the mold, at least one of the upper mold and the lower mold and the glass material Performing a first pressing step of pressing the mold with a first pressing force forming a predetermined gap therebetween,
In the main molding step performed after the pre-molding step,
After performing a cooling process for cooling the glass material to a second molding temperature lower than the first molding temperature via the mold, the mold is applied with a second pressing force higher than the first pressing force. The glass forming method characterized by performing the 2nd press process which presses.

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