JP7196855B2 - Method for manufacturing bent base material and mold for bent base material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a bent base material and a mold for the bent base material.

As a technique for forming a flat glass sheet into a desired shape, the mold is tilted to bring one edge of the flat glass sheet into contact with the alignment pin of the mold, and the glass sheet is shaped into the mold by heating in that state. A technique is known in which the surface shape of a molded glass article is formed by sagging onto the molding surface (see Patent Document 1).

Japanese Patent No. 5639658

By the way, as described above, it is difficult to match the external shape of the bent base material after molding to the target final external shape simply by sagging the sheet glass onto the molding surface. For this reason, the above molding method may result in a glass article having poor accuracy in outer dimensions. In order to improve the accuracy of the external dimensions in the molding method described above, it was necessary to carry out complicated post-processing such as grinding the periphery of the molded glass article after molding to finish the desired final external shape.
Moreover, in the above-described molding method, since the plate glass is formed by tilting the mold, gravity acts on the plate glass in a biased manner, and there is a possibility that the glass plate will be distorted and deteriorate in quality.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a bent base material and a mold for the bent base material, which can easily form a high-quality bent base material by positioning it on a molding surface with high accuracy.

The present invention consists of the following configurations.
(1) A manufacturing method for molding a preform substrate along a molding surface of a mold into a curved substrate having at least a portion thereof curved,
Of the vertical directions at any point on the molding surface, if the direction in which the preform base material curves during molding is downward, the opposite direction is upward, and the other than the molding surface in top view is outside,
a base material placing step of placing the preform base material from above the molding surface having the same outer shape as that of the bent base material;
a molding step of heating and softening the preform base material so that the preform base material is formed into the bent base material along the molding surface by its own weight,
In the base material placing step, placing the preform base material on a mold having a guide member having a guide portion inclined from the outside of the molding surface toward the edge of the molding surface,
In the molding step, the peripheral edge portion of the preform substrate is brought into contact with the guide portion and slid to guide the peripheral edge portion of the preform substrate toward the edge portion of the molding surface. Production method.
(2) A mold that molds a preform base material into a curved base material that is at least partially curved along the molding surface of the mold,
the molding surface having the same outline as the curved base material;
a guide member having a guide portion inclined from the outside of the molding surface toward the edge of the molding surface;
with
The guide member guides the peripheral portion of the preform base material toward the edge portion of the molding surface by causing the peripheral portion of the preform base material to contact and slide on the guide portion.
Forming mold for bending base material.

According to the present invention, a high-quality bent base material can be easily molded by positioning it on the molding surface with high accuracy.

4 is a perspective view of a bending base material according to the present embodiment; FIG. FIG. 4 is a plan view of a bent base material according to the present embodiment; (A) to (C) are cross-sectional views showing the chamfered shape at the edge of the bent base material according to the present embodiment. 1 is a perspective view of a bent substrate and a preform substrate; FIG. FIG. 2 is a plan view of a bent base material and a preform base material; FIG. 2 is a perspective view of a forming apparatus for forming a preform base material into a bent base material; FIG. 2 is a plan view of a forming apparatus for forming a preform base material into a bent base material; It is a perspective view of a molding device and a guide member. It is a figure explaining the shaping|molding method of the bending|flexion base material using a shaping|molding apparatus, Comprising: (a) to (c) are perspective views of the shaping|molding apparatus in a shaping|molding process, respectively. FIG. 4 is a plan view of part of a molding apparatus for explaining variation and positioning of the preform base material due to molding. It is a figure explaining the specific example of shaping|molding which shape|molds a preform base material in a bent base material, (a)-(f) is a schematic perspective view of the shaping|molding apparatus in a shaping|molding process, respectively. It is a figure explaining the specific example of shaping|molding which shape|molds a preform base material in a bent base material, (a)-(f) is a schematic side view of the shaping|molding apparatus in a shaping|molding process, respectively. It is a figure explaining the specific example of shaping|molding which shape|molds a preform base material in a bent base material, (a) to (f) is a schematic plan view of the shaping|molding apparatus in a shaping|molding process, respectively. FIG. 11 is a perspective view of a molding device used in another embodiment; It is a top view of the shaping|molding apparatus used by other embodiment. It is a perspective view of a molding device and a guide member. It is a figure explaining the shaping|molding method of the bending|flexion base material using a shaping|molding apparatus, Comprising: (a) to (c) are perspective views of the shaping|molding apparatus in a shaping|molding process, respectively.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. A glass plate will be exemplified as the bending base material 10 for explanation.
FIG. 1 is a perspective view of a bending base material 10 according to this embodiment. FIG. 2 is a plan view of the bending base material 10 according to this embodiment. (A) to (C) of FIG. 3 are cross-sectional views showing chamfered shapes at the edges of the bending base material 10 according to the present embodiment.

As shown in FIGS. 1 and 2, the bending base material 10 has one principal surface 11 (lower surface in the drawings), the other principal surface 12 (the upper surface opposite to the principal surface 11 in the drawings), It is a glass plate having The bent base material 10 is a base material having a three-dimensional shape concavely curved downward along the X direction and the Y direction. This bending base material 10 is used, for example, as a base material such as a mirror of a head-up display or a cover glass of an on-vehicle product. As shown in FIG. 3A, the bent base material 10 is chamfered into a convex curved shape at the corners 13 at the edges thereof. The chamfered shape of the corner portion 13 includes a double-sided C-chamfered shape shown in FIG. 3A and a double-sided R-chamfered shape shown in FIG. 3B. Further, as shown in FIG. 3C, at least the contact portion between the guide portion 53 and the corner portion 13 is preferably rounded on one side. The chamfer R may be a spline curve instead of a single curve.
The minimum chamfering radius of the single-sided R-chamfering shape shown in FIG. 3C is preferably 0.1 mm or more. As a result, the concentrated load at the time of contact can be dispersed, and damage to the glass during molding can be suppressed. Furthermore, the minimum chamfer radius of the single-sided R-chamfer shape is preferably 20 mm or less. As a result, the guide portion and the corner portion are likely to come into point contact during molding, making the glass slippery. The boundary portion of the R-chamfered portion may be connected so that the curvature is continuous, or may be C-chamfered to remove the corners.

The X-direction dimension a, Y-direction dimension b, and plate thickness t of the bending base material 10 are not particularly limited. It is preferable that the plate thickness t be substantially constant over the entire area of the bent base material 10 . Further, the plate thickness t may vary partially or may vary over the entire area of the bent base material 10 .

Examples of the bending base material 10 include glass plates such as crystallized glass and colored glass in addition to colorless and transparent amorphous glass.

More specifically, examples of glass that can be used include non-alkali glass, soda lime glass, soda lime silicate glass, aluminosilicate glass, borosilicate glass, lithium aluminosilicate glass, and borosilicate glass. An aluminosilicate glass is preferable because even if it is thin, a large stress is likely to be applied by tempering treatment, and a high-strength glass can be obtained even if it is thin.

A specific example of the glass composition is a composition represented by mol % based on oxides, and contains 50 to 80% SiO ₂ , 0.1 to 25% Al ₂ O ₃ , and 3 to 3 Li ₂ O+Na ₂ O+K ₂ O. 30% MgO, 0-25% CaO, 0-25% CaO, and 0-5% ZrO ₂ , but not limited thereto. More specifically, the following glass compositions may be mentioned. Note that, for example, "containing 0 to 25% MgO" means that MgO is not essential, but may be contained up to 25%. The glass of (i) is included in soda lime silicate glass, and the glasses of (ii) and (iii) are included in aluminosilicate glass. The glass of (v) is included in the lithium aluminosilicate glass.
(i) 63-73% SiO ₂ , 0.1-5.2% Al ₂ O ₃ , 10-16% Na ₂ O, K ₂ O in a composition expressed in mole % based on oxides; A glass containing 0-1.5%, 0-5% Li ₂ O, 5-13% MgO and 4-10% CaO.
(ii) a composition, expressed in mole percent on an oxide basis, of 50-74% SiO ₂ , 1-10% Al ₂ O ₃ , 6-14% Na ₂ O, and 3-11% K ₂ O; , 0-5% Li ₂ O, 2-15% MgO, 0-6% CaO and 0-5% ZrO ₂ , and the total content of SiO ₂ and Al ₂ O ₃ is 75% or less , the total content of Na ₂ O and K ₂ O is 12-25%, and the total content of MgO and CaO is 7-15%.
(iii) a composition, expressed in mole % based on oxides, containing 68-80% SiO ₂ , 4-10% Al ₂ O ₃ , 5-15% Na ₂ O, and 0-1% K ₂ O; , 0-5% Li ₂ O, 4-15% MgO and 0-1% ZrO ₂ .
(iv) a composition, expressed in mole percent on an oxide basis, of 67-75% SiO ₂ , 0-4% Al ₂ O ₃ , 7-15% Na ₂ O, and 1-9% K ₂ O; , containing 0-5% Li ₂ O, 6-14% MgO and 0-1.5% ZrO ₂ , the total content of SiO ₂ and Al ₂ O ₃ being 71-75%, Na ₂ O and a glass in which the total content of K ₂ O is 12-20% and the content of CaO, if any, is less than 1%.
(v) a composition expressed in mole % based on oxides containing 56-73% SiO ₂ , 10-24% Al ₂ O ₃ , 0-6% B ₂ O ₃ , and 0-6% P ₂ O ₅ ; 6% Li ₂ O, 2-7% Na ₂ O, 3-11% Na 2 O, 0-2% K ₂ O, 0-8% MgO, 0-2% CaO, 0-5% SrO , 0-5% BaO, 0-5% ZnO, 0-2% TiO ₂ and 0-4% ZrO ₂ .

For the glass plate, for example, the total content of Li ₂ O and Na ₂ O in the glass composition is preferably 12 mol % or more in order to perform chemical strengthening treatment appropriately. Furthermore, when the content of Li ₂ O in the glass composition increases, the glass transition point decreases and molding becomes easier _. 2 mol % or more is more preferable. Furthermore, in order to increase the surface compressive stress (hereinafter also abbreviated as CS) and surface compressive stress layer depth (Depth of Layer; hereinafter also abbreviated as DOL), the glass composition contains SiO ₂ at 60 mol% or more, Al It preferably contains 8 mol % or more of ₂ O ₃ .

Furthermore, when the glass plate is colored and used, a coloring agent may be added within a range that does not impede the achievement of the desired chemical strengthening properties. For example _{, Co3O4} , MnO, MnO, which are metal oxides of Co, Mn, Fe, Ni, Cu, Cr, V, Bi, Se, Ti, Ce, Er, and Nd, which have absorption in the visible region. ₂ , _{Fe2O3 , NiO} , CuO, _Cu2O , _Cr2O3 , _{V2O5 , Bi2O3 , SeO2} , _TiO2 , _CeO2 , _{Er2O3 , Nd2O3 ,} etc. mentioned.

When colored glass is used for the glass plate, the coloring components (Co, Mn, Fe, Ni, Cu, Cr, V, Bi, Se, Ti, Ce, Er, and Nd at least one component selected from the group consisting of metal oxides) may be contained in the range of 7% or less. If the coloring component exceeds 7%, the glass tends to devitrify. This content is preferably 5% or less, more preferably 3% or less, and even more preferably 1% or less. Further, the glass plate may appropriately contain SO ₃ , chloride, fluoride, etc. as a clarifier during melting.

Here, a method for manufacturing the preform base material 10P, which is flat glass that can be used as the material of the bending base material 10, will be described. First, raw materials for each component are prepared so as to have the above-described composition, and heated and melted in a glass melting kiln. The glass is homogenized by bubbling, stirring, addition of a clarifier, etc., a glass plate having a predetermined thickness is produced by a known molding method, and then slowly cooled. Examples of methods for producing glass include a float method, a press method, a fusion method, a down-draw method and a roll-out method. In particular, the float method suitable for mass production is suitable. Continuous fabrication methods other than the float method, ie, the fusion method and the down-draw method are also suitable. A flat glass plate produced by an arbitrary production method is cut into a desired size after slow cooling to obtain a flat glass. If more accurate dimensional accuracy is required, the glass plate after cutting may be subjected to polishing/grinding, edge processing, or perforating. As a result, it is possible to reduce cracking and chipping during handling in a heating process, etc., and improve the yield.

The bendable base material 10 may have a treatment layer. There are no particular restrictions on the treatment layer. Examples of the treatment layer include an antiglare layer that scatters reflected light and reduces the glare of the reflected light due to glare of the light source. The treated layers may be formed by processing the main surfaces 11 and 12 of the bending base material 10 itself, or may be formed by a separate deposition treatment method. As a method for forming the treatment layer, for example, surface treatment may be applied to at least part of the bending base material 10 by chemical treatment or physical treatment. In the case of the antiglare layer, a method of forming an uneven shape with a desired surface roughness can be used. Moreover, unevenness may be formed on at least a part of the bent base material 10 by a deposition treatment method of applying or spraying a treatment liquid, or a thermal treatment method such as molding. As the treatment layer, an antireflection layer (AR layer) and an anti-fingerprint wiping layer (AFP layer) may also be formed.

When the bending base material 10 is glass, the thickness t of the glass used for molding is preferably 0.5 mm or more and 5 mm or less. If the glass has a thickness equal to or greater than this lower limit value, the bending base material 10 can have high strength and good texture. Further, the thickness t of the glass is more preferably 0.7 mm or more and 3 mm or less, and still more preferably 1 mm or more and 3 mm or less.

FIG. 4 is a perspective view of the bent base material 10 and the preform base material 10P. FIG. 5 is a plan view of the bent base material 10 and the preform base material 10P.

As shown in FIGS. 4 and 5, the bent base material 10 is obtained by bending a flat preform base material 10P. The preform base material 10P is a flat glass plate obtained by inverse calculation from the shape of the bent base material 10, which is a molded product. Specifically, the preform base material 10P is obtained by flattening the bent base material 10 by a simulation with a uniformly distributed load, and as shown in FIG. is a flat glass plate with a large outer shape.

Next, a molding apparatus for manufacturing the bent base material 10 will be described.
FIG. 6 is a perspective view of a molding device 20 that molds the preform base material 10P into the bent base material 10. FIG. FIG. 7 is a plan view of a molding device 20 that molds the preform base material 10P into the bent base material 10. FIG. 8 is a perspective view of the molding device 20 and the guide member 50. FIG.

As shown in FIGS. 6 and 7, the molding device 20 includes a molding die 30 and a guide member 50. As shown in FIGS. The forming device 20 is a device that bends a flat preform base material 10</b>P that is the material of the bent base material 10 and forms the bent base material 10 .

The molding die 30 has a molding surface 31 on its upper surface, and a guide member 50 is provided around the molding surface 31 . The molding surface 31 is formed in a three-dimensional shape concavely curved downward along the Y direction and the X direction. The molding surface 31 is a molding surface that molds the preform base material 10P into the shape of the bent base material 10 by bringing one main surface 11 of the preform base material 10P, which is the material of the bent base material 10, into close contact. . The guide member 50 is a member that guides and positions the preform base material 10</b>P to the molding surface 31 . A preform base material 10</b>P is placed on the mold 30 having the molding surface 31 from above the molding surface 31 . The preform base material 10</b>P placed on the mold 30 is guided by the guide member 50 and positioned on the molding surface 31 . Specifically, in the present embodiment, since the preform base material 10P has a substantially rectangular shape, the plurality of guide members 50 are provided on both sides of the preform base material 10P in the longitudinal direction (Y direction) and on the preform base material 10P. are arranged on both sides in the short direction (X direction) of the .

A plurality of suction holes 32 are formed in the molding surface 31 . A suction hose (not shown) from a vacuum pump (not shown) is connected to these suction holes 32 so that suction can be performed by the vacuum pump. A plurality of fitting recesses 33 are formed around a molding surface 31 on the upper surface of the molding die 30 , and guide members 50 are fitted and mounted in these fitting recesses 33 . As a result, a plurality of guide members 50 are erected around the molding surface 31 of the molding die 30 at intervals.

The material of the mold 30 is preferably oxidation-resistant metal such as stainless steel, glass such as fused silica glass, ceramic, or carbon, and more preferably glass such as fused silica glass and carbon. Fused silica is highly resistant to high temperatures and in an oxidizing atmosphere, and is less likely to cause defects in the preform base material 10P in contact with the molding surface 31, so that the curved base material 10 with less scratches can be obtained. Carbon has a high thermal conductivity and can efficiently produce the bent base material 10 . A coating of metal, oxide, carbon, or the like may be formed on the molding surface 31 of the molding die 30 .

As shown in FIG. 8, the guide member 50 is formed like a pin and has a straight portion 51 and an inclined portion 52 . The straight portion 51 is formed in a cylindrical shape, and the inclined portion 52 is formed in a conical shape. As a result, the guide member 50 has a shape in which the cross-sectional area of the inclined portion 52 gradually increases downward.

The guide member 50 is erected around the molding surface 31 of the molding die 30 by fitting the straight portion 51 into the fitting recess 33 of the molding die 30 . The guide member 50 is fitted in the fitting recess 33 , and the upper end portion of the straight portion 51 slightly protrudes from the upper surface of the mold 30 . The projection dimension of the straight portion 51 from the upper surface of the mold 30 is 0 mm or more at the portion closest to the molding surface 31, and preferably equal to or less than the thickness t of the preform base material 10P.

The guide member 50 is attached to the molding die 30 with the straight portion 51 fitted in the fitting recess 33 of the molding die 30 , and the molding surface 31 side of the inclined portion 52 serves as a linear guide portion 53 . The guide portion 53 is inclined from the outside of the molding surface 31 toward the edge of the molding surface 31, and the peripheral portion of the preform base material 10P comes into point contact with the guide portion 53. As shown in FIG.

The guide portion 53 of the guide member 50 has a coefficient of static friction of 0.5 or less at the molding temperature when the preform base material 10P is molded into the bent base material 10 . The molding temperature for molding the preform base material 10P into the bent base material 10 is preferably a temperature higher than the glass transition temperature and lower than the melting point, or a temperature at which the equilibrium viscosity of the preform base material 10P becomes 10 ¹⁷ Pa·s or lower. , for example, 500°C to 700°C is preferred. The coefficient of static friction of the guide portion 53 is preferably 0.5 or less, more preferably 0.3 or less. This is to suppress local deformation of the preform base material 10P due to contact resistance with the guide portion 53 . The static friction coefficient of the guide portion 53 has no particular lower limit, but is preferably 0.01 or more, more preferably 0.05 or more. This is to prevent the position of the preform base material 10P from being extremely displaced when the preform base material 10P is initially installed. The static friction coefficient can be measured by the method described in JIS K 7125.

The guide portion 53 has a surface roughness of 50 nm to 1000 nm. The surface roughness Ra of the guide portion 53 is preferably 1000 nm or less, more preferably 500 nm or less. This is because the contact surface with the preform base material 10P maintains a certain degree of surface strength. Further, the surface roughness Ra of the guide portion 53 is preferably 50 nm or more, more preferably 100 nm or more. This is to reduce the real contact surface with the preform base material 10P, reduce the resistance due to friction, and prevent local deformation of the preform base material 10P.

The guide portion 53 has an inclination angle of 45° to 89° with respect to the bottom surface of the straight portion 51 . The inclination angle of the guide portion 53 is preferably 89° or less, more preferably 80° or less. This is to reduce the normal stress between the preform base material 10P and the guide portion 53 during molding, reduce the frictional force, and suppress local deformation of the preform base material 10P. The inclination of the guide portion 53 is preferably 45° or more, more preferably 50° or more. This is to prevent the preform base material 10P from finally remaining on the guide portion 53 and being locally deformed.

The material of the guide member 50 is preferably oxidation-resistant metal such as stainless steel, glass such as fused silica glass, ceramic, or carbon. Moreover, it is preferable that the guide member 50 is coated with a low-friction material at least on the guide portion 53 with which the peripheral portion of the preform base material 10P contacts. Tungsten disulfide (WS ₂ ), molybdenum disulfide (MoS ₂ ), boron nitride (BN) and the like are preferable as the low-friction material coating. As the guide member 50, for example, a film such as carbon may be formed on the outer peripheral surface, or the guide member 50 may be formed from carbon alone. Also, the edges of the glass may be coated. Tungsten disulfide (WS ₂ ), molybdenum disulfide (MoS ₂ ), boron nitride (BN), carbon (C) and the like are preferable as the low-friction coating. By coating at least the guide portion 53 with a low-friction material, coating the edge of the glass, or selecting the material of the guide member 50 itself, the guide portion 53 has a desired coefficient of static friction.

The mold 30 of the molding apparatus 20 for molding the bent base material 10 is moved in one cycle inside a heating furnace (not shown) having a loading/unloading zone, a heating zone, and a slow cooling zone. Then, the mold 30 is repeatedly moved between the loading/unloading zone, the heating zone, and the slow cooling zone of the heating furnace, thereby continuously producing the bent base material 10 .

Next, a method for forming the bent base material 10 using the above-described forming apparatus 20 will be described.
9A to 9C are perspective views of the forming apparatus 20 in the forming process, respectively, for explaining the method of forming the bent base material 10 using the forming apparatus 20. FIG. FIG. 10 is a plan view of part of the molding apparatus 20 for explaining the variation and positioning of the preform base material 10P due to molding.

(Molding of preform base material)
First, a preform base material 10P having an outer shape obtained by flattening the bent base material 10 with a uniformly distributed load by simulation is prepared (see FIGS. 4 and 5).

(Base material placement step)
In the loading/unloading zone of the heating furnace, the preform substrate 10P is set in the molding device 20 as shown in FIG. 9(a). Specifically, the preform base material 10P is placed inside the plurality of guide members 50 from above the molding die 30 of the molding device 20 by a conveying mechanism (not shown). At this time, the flat preform base material 10</b>P has a larger outer shape in plan view than the molding surface 31 which has the same outer shape in plan view as the bent base material 10 . Therefore, as shown in FIG. 10, the preform base material 10P protrudes from the molding surface 31 at its peripheral edge and abuts against the guide portion 53 of the inclined portion 52 of the guide member 50 erected around the molding surface 31. and is locked (see dotted line in FIG. 10). As a result, the preform base material 10</b>P is supported at its peripheral portion by the inclined portion 52 of the guide member 50 and is arranged at a position spaced upward from the molding surface 31 . The mold 30 is heated to about 400° C. in a heating furnace.

(Molding process)
Mold 30 moves to the heating zone of the furnace. Thereby, the preform base material 10P is heated to the molding temperature.

As shown in FIG. 9B, the preform base material 10P is softened by being heated to the molding temperature. Then, since the preform base material 10P is in contact with the guide portion 53 of the guide member 50 at its peripheral portion, its central portion hangs down due to its own weight. As a result, the outer shape of the preform base material 10</b>P in plan view gradually becomes smaller, and the peripheral edge portion in contact with the guide portion 53 slides down due to its own weight while contacting the guide portion 53 . As a result, as shown in FIG. 9(c), the preform base material 10P is guided to the molding surface 31 by the guide portion 53, thereby being aligned with the molding surface 31 as shown in FIG. It is arranged so as to hang down by its own weight on the molding surface 31 of the mold 30 (see the solid line in FIG. 10). In addition, when the central portion of the preform base material 10P hangs down due to its own weight, the upper surface of the preform base material 10P may be pressed at least partially.

In this molding process, for example, if the center of gravity of the preform base material 10P is deviated from the center, or if the preform base material 10P is tilted and set, the center of gravity side or the lower side of the inclination of the preform base material 10P is set first. It slides down and the edge of one end comes into contact with the straight portion 51 of the guide member 50 . In this case, when the preform base material 10P softens after that and the deflection due to its own weight increases, the center portion of the preform base material 10P approaches the molding surface 31 with the point of contact with the straight portion 51 as a base point, and The edges other than the end slide down while contacting the guide portion 53 , and are aligned with the molding surface 31 and placed on the molding surface 31 . In addition, the sliding property may be improved by applying vibration to the guide member 50 .

(adsorption process)
With the preform substrate 10P placed on the molding surface 31 of the molding die 30, the vacuum pump is driven, and the suction holes 32 formed in the molding surface 31 move the air between the molding surface 31 and the preform substrate 10P. Air is sucked. As a result, the preform base material 10P is brought into close contact with the molding surface 31 while being positioned on the molding surface 31 with high accuracy, and the curved surface shape of the molding surface 31 is transferred to form the bent base material 10 having the desired curved shape. be. The preform base material 10P may not only be given a curved shape by suction with a vacuum pump, but may also be pressed at least partly from the upper surface of the preform base material 10P, or these may be combined.

(Slow cooling and extraction process)
After that, the mold 30 with the bent base material 10 in close contact with the molding surface 31 is moved to the slow cooling zone, whereby the bent base material 10 is cooled below the strain point. Then, the cooled bent base material 10 is taken out from the mold 30 by the conveying mechanism. A preform base material 10P for molding the next bent base material 10 is placed on the mold 30 from which the bent base material 10 has been taken out.

Here, a specific example of molding when forming the bent substrate 10 by molding the preform substrate 10P having a thickness t of 1.8 mm by the molding device 20 will be described. The coefficient of static friction of the guide portion 53 of the molding die 30 is assumed to be 0.1, and the molding temperature is assumed to be 630.degree.

FIGS. 11(a) to 13(f) are diagrams for explaining a specific example of molding for molding the preform base material 10P into the bent base material 10. FIG. 11A to 11F are schematic perspective views of the molding apparatus 20 in the molding process, and FIGS. 12A to 12F are schematic side views of the molding apparatus 20 in the molding process. 13A to 13F are schematic plan views of the molding apparatus 20 in the molding process.

When the preform base material 10P is set in the mold 30 (see FIGS. 11(a), 12(a) and 13(a)) and heated to the molding temperature (630° C.), About 1 second after setting, the preform base material 10P whose peripheral edge portion is supported by the guide portion 53 is slightly bent at the center side due to its own weight, and the external shape in plan view becomes slightly smaller.

Then, the center of gravity side of the preform base material 10P slides down first, and the edge of one end contacts the straight portion 51 of the guide member 50 (FIGS. 11(b), 12(b) and 13 ( b) see).

About 3 seconds after setting, the preform base material 10P is further softened, resulting in increased deflection due to its own weight, and its central portion approaches the molding surface 31 (FIGS. 11(c), 12(c) and 13). (c)), the edges other than one end slide down while contacting the guide portion 53 .

About 10 seconds after setting, the preform base material 10P is positioned on the molding surface 31, its peripheral edge contacts the straight portion 51 of the guide member 50, and the outer peripheral side of the main surface 11 contacts the molding surface 31 ( 11(d), 12(d) and 13(d)).

About 110 seconds after setting, the preform base material 10P has a slight gap in the central portion with respect to the molding surface 31, and other portions except for the central portion come into close contact (FIG. 11(e)). , see FIGS. 12(e) and 13(e)).

In this state, when air between the molding surface 31 and the preform base material 10P is sucked from the suction hole 32 at 0.08 MPa by a vacuum pump, the entire main surface 11 on the lower side of the preform base material 10P becomes the molding surface. 31 in a highly accurate position (see FIGS. 11(f), 12(f) and 13(f)). As a result, the curved surface shape of the molding surface 31 is transferred to the preform base material 10</b>P to form the bent base material 10 having a desired curved shape.

As described above, according to the method for manufacturing the bent base material 10 according to the present embodiment, the preform base material 10P is hung down along the molding surface 31, thereby producing a high-quality bent base material in which at least a part is curved. 10 can be easily molded. Moreover, when the preform base material 10P is molded into the bent base material 10 by its own weight, the guide portion 53 of the guide member 50 guides the peripheral edge portion of the preform base material 10P toward the peripheral edge of the molding surface 31, so that the bent base material 10P is bent. The preform base material 10P can be accurately positioned on the molding surface 31 having the same outer shape as the base material 10 . As a result, complicated post-processing such as grinding after molding to finish the outer shape to the final shape can be eliminated. In this way, the preform base material 10P can be positioned on the molding surface 31 of the mold 30 with high accuracy, and the bent base material 10 of high quality can be easily molded. The molding surface 31 having the same external shape as the bending base material 10 does not have to have the external shape of the bending base material 10 completely identical to the external shape of the molding surface 31 as long as at least a part thereof matches. A match of 50% or more is preferred, and a match of 70% or more is more preferred.

In particular, the peripheral edge portion of the preform base material 10P that hangs under its own weight is adjusted to the peripheral edge of the forming surface 31 by the guide portions 53 of the guide members 50 that are provided at opposite positions across the molding surface 31 in the direction in which the preform base material 10P is curved. The preform base material 10P can be accurately positioned on the molding surface 31 by smoothly guiding the preform base material 10P toward the molding surface 31.例文帳に追加

Moreover, by chamfering the corners 13 of the peripheral edge portion of the preform base material 10P in advance, the peripheral edge portion of the preform base material 10P can slide well with respect to the guide portion 53 of the guide member 50. FIG. As a result, the guide portion 53 smoothly guides the peripheral portion of the preform base material 10</b>P to the edge portion of the molding surface 31 .

Further, by setting the coefficient of static friction of the guide portion 53 of the guide member 50 to 0.5 or less at the temperature in the molding process, the peripheral portion of the preform base material 10P slides well on the guide portion 53 of the guide member 50. can. As a result, the guide portion 53 smoothly guides the peripheral portion of the preform base material 10</b>P to the edge portion of the molding surface 31 .

In addition, by forming the preform base material 10P to have an outer shape when the bent base material 10 is flattened, when the preform base material 10P is molded to form the bent base material 10, the bent base material 10P formed by the bending can be formed. The substrate 10 can be accurately contoured to the target.

Furthermore, the preform base material 10P is securely adhered to the molding surface 31 by the suction process. As a result, the molding accuracy can be further increased, and the quality can be improved.

Also, in the molding process, a part of the peripheral portion of the preform base material 10P is engaged with the straight portion 51 of the guide member 50 . As a result, even if the preform base material 10P hangs down obliquely due to the deviation of the center of gravity or the inclination when placed, the lower edge portion is locked by the straight portion 51, and then the other portion of the peripheral edge portion is held. It is guided by the guide portion 53 of the guide member 50 and positioned on the molding surface. Thereby, the preform base material 10P can be reliably positioned on the molding surface 31 .

Further, the peripheral edge of the preform base material 10P is accurately guided to the edge of the forming surface 31 while making point contact with the linear guide portion 53 of the pin-shaped guide member 50 .

According to the bent base material 10 manufactured by the method for manufacturing the bent base material 10 according to the present embodiment, at least a portion of the bent base material 10 is curved, and the corners 13 in the peripheral edge portion are chamfered at the preform shape stage of 2D. Therefore, there is no need to grind and chamfer the 3D-shaped periphery after molding . Therefore, the shape tolerance of the chamfered cross-sectional shape of the peripheral portion can be set to ±0.1 mm or less, and the outer dimension tolerance of the peripheral portion can be ±0.2 mm or less. As a result, the bending equipment 10 can be used as various base materials such as head-up display mirrors and vehicle-mounted cover glasses.

(Other embodiments)
Next, another embodiment will be described.
In addition, the same reference numerals are given to the same components as those of the above-described embodiment, and the description thereof is omitted.

FIG. 14 is a perspective view of molding device 20 used in another embodiment. FIG. 15 is a plan view of a molding device 20 used in another embodiment. 16 is a perspective view of the molding device 20 and the guide member 70. FIG.

As shown in FIGS. 14 and 15, in another embodiment, the bending base material 10 is formed using a mold 30 having a pin-shaped guide member 50 and a pair of block-shaped guide members 70 . molding. The guide members 70 are arranged at positions facing each other. The guide member 70 also has a straight portion 71 and an inclined portion 72, and the inclined portion 72 is shaped such that its cross-sectional area gradually increases downward.

As shown in FIG. 16, when the guide member 70 is attached to the molding die 30 with the straight portion 71 fitted in the fitting recess 33 of the molding die 30, the molding surface 31 side of the inclined portion 72 is planar. is a guide portion 73 of . The guide portion 73 of the guide member 70 is brought into contact with the peripheral portion of the preform base material 10P. The guide portion 73 is inclined from the outside of the molding surface 31 toward the edge of the molding surface 31 . The guide portion 73 is formed in a wide shape, so that the peripheral portion of the preform base material 10P is in line contact with the guide portion 73 .

Next, a molding method using the molding die 30 will be described.
17A to 17C are perspective views of the forming apparatus 20 in the forming process, respectively, for explaining the method of forming the bent base material 10 using the forming apparatus 20. FIG.

(Molding of preform base material)
First, a preform base material 10P obtained by flattening the bent base material 10 with a uniformly distributed load by simulation is prepared (see FIGS. 4 and 5).

(Base material placement step)
In the loading/unloading zone of the heating furnace, as shown in FIG. 17(a), the preform substrate 10P is set on the mold 30 of the molding device 20 by the transport mechanism. Specifically, the preform base material 10</b>P is placed inside a plurality of guide members 50 and 70 erected on the mold 30 from above the molding surface 31 of the mold 30 . At this time, the flat preform base material 10P, which has a larger outer shape in plan view than the bent base material 10, has its peripheral edge portion inclined portions 52, 72 of the guide members 50, 70 erected around the molding surface 31. are brought into contact with the guide portions 53, 73 and locked.

(Molding process)
The mold 30 is moved to the heating zone of the heating furnace, and the preform substrate 10P is heated to the molding temperature. When the preform base material 10P is heated to the molding temperature and softened, as shown in FIG. Its central part hangs down by its own weight. Then, the outer shape of the preform base material 10</b>P in plan view gradually becomes smaller, and the peripheral edge portion in contact with the guide portions 53 and 73 slides down due to its own weight while contacting the guide portions 53 and 73 . As a result, as shown in FIG. 17(c), the preform base material 10P is guided to the molding surface 31 by the guide portions 53 and 73, and is aligned with the molding surface 31. 31 so that it hangs under its own weight. At this time, since the guide member 70 is formed to have a wide width, the preform base material 10P slides down while the edges of both ends of the preform base material 10P are in line contact with the guide portions 73 formed by the surfaces of the guide member 70 .

In this molding process, for example, if the center of gravity of the preform base material 10P is deviated from the center, or if the preform base material 10P is tilted and set, the center of gravity side or the lower side of the inclination of the preform base material 10P comes first. It slides down and the edge of one end comes into contact with the straight portion 71 of the guide member 70 . Then, when the preform base material 10P softens and bends due to its own weight, the center portion of the preform base material 10P approaches the molding surface 31 with the point of contact with the straight portion 71 as a base point. edges slide down while contacting the guide portions 53 and 73 and are positioned on the molding surface 31 in alignment with the molding surface 31 .

(adsorption process)
With the preform substrate 10P placed on the molding surface 31 of the molding die 30, the vacuum pump is driven, and the suction holes 32 formed in the molding surface 31 move the air between the molding surface 31 and the preform substrate 10P. Air is sucked. As a result, the preform base material 10P is brought into close contact with the molding surface 31 while being positioned on the molding surface 31 with high accuracy, and the curved surface shape of the molding surface 31 is transferred to form the bent base material 10 having the desired curved shape. be.

(Slow cooling and extraction process)
After that, the mold 30 with the bent base material 10 in close contact with the molding surface 31 is moved to the slow cooling zone, whereby the bent base material 10 is cooled below the strain point. Then, the cooled bent base material 10 is taken out from the mold 30 by the conveying mechanism. A preform base material 10P for molding the next bent base material 10 is placed on the mold 30 from which the bent base material 10 has been taken out.

In other embodiments, when the preform base material 10P is formed into the bent base material 10 by its own weight, the guide portions 53 and 73 of the guide members 50 and 70 guide the peripheral edge portion of the preform base material 10P to the forming surface 31. , the preform base material 10P can be accurately positioned on the molding surface 31 having the same outer shape as the bent base material 10. As shown in FIG. As a result, complicated post-processing such as grinding after molding to finish the outer shape to the final shape can be eliminated. Thus, other embodiments can position the preform base material 10P on the molding surface 31 of the mold 30 with high accuracy and easily mold the high-quality bent base material 10 .

In particular, the molding die 30 accurately guides the edge of the preform base material 10P to the edge of the molding surface 31 while bringing the peripheral edge of the preform base material 10P into line contact with the planar guide portion 73 of the block-shaped guide member 70 .

In the above-described embodiment, the curved base material 10 is molded by the molding surface 31 that is recessed downward. Alternatively, the bending base material 10 may be molded with a molding surface 31 that curves up and down to form a concave-convex shape on the front and back.

The guide portions 53 and 73 of the inclined portions 52 and 72 of the guide members 50 and 70 may have a gentle shape that guides the peripheral edge portion of the preform base material 10P to the edge portion of the molding surface 31. Not exclusively. For example, the guide portions 53 and 73 may have a curved shape that gently dents or a curved shape that gently bulges.

Further, as the guide member to stand on the molding die 30, a conical pin-shaped guide member 50 or a guide member 50 having a guide portion for guiding the edge of the preform base material 10P to the edge of the molding surface 31 may be used. The guide member 70 is not limited to the wide block-shaped guide member 70, and may be, for example, a triangular pyramid.

Further, in the above-described embodiment, the case of forming the bending base material 10 that curves along the X direction and the Y direction was exemplified. may In this case, the molding die 30 may be provided with the guide member 50 or the guide member 70 only on the end side in the bending direction (Y direction).

Further, the bending base material 10 to be molded is not limited to a glass plate, and may be a plate of ceramics, resin, wood, metal, or the like.

Also, in the molding apparatus of the present invention, a plurality of guide members may have the same shape as in the embodiment shown in FIG. may have different shapes.
Moreover, the preform base material may be brought into contact with all of the plurality of guide members at the stage of being set in the molding apparatus. Alternatively, the preform base material is brought into contact with part of the plurality of guide members when it is set in the molding apparatus, and the number of the plurality of guide members in contact is increased when the preform base material hangs down. may

As described above, this specification discloses the following matters.
(1) A manufacturing method for molding a preform substrate along a molding surface of a mold into a curved substrate having at least a portion thereof curved,
Of the vertical directions at any point on the molding surface, if the direction in which the preform base material curves during molding is downward, the opposite direction is upward, and the other than the molding surface in top view is outside,
a base material placing step of placing the preform base material from above the molding surface having the same outer shape as that of the bent base material;
a molding step of heating and softening the preform base material so that the preform base material is formed into the bent base material along the molding surface by its own weight,
In the base material placing step, placing the preform base material on a mold having a guide member having a guide portion inclined from the outside of the molding surface toward the edge of the molding surface,
In the molding step, the peripheral edge portion of the preform base material is brought into contact with the guide portion and slid to guide the peripheral edge portion of the preform base material toward the edge portion of the molding surface.
A method for producing a flexible base material.
According to this bending base material manufacturing method, a high-quality bending base material having at least a portion thereof curved can be easily formed by hanging the preform base material along the molding surface. Moreover, when the preform base material is formed into the bent base material by its own weight, the guide portion of the guide member guides the peripheral edge portion of the preform base material toward the peripheral edge of the molding surface. A preform base material can be accurately positioned on a molding surface having an outer shape. As a result, complicated post-processing such as grinding after molding to finish the outer shape to the final shape can be eliminated. In this manner, the manufacturing method can position the preform base material on the molding surface of the mold with high accuracy and easily form a high-quality bent base material.

(2) The method for producing a bent base material according to (1), wherein the guide members are provided at opposing positions across at least the molding surface.
According to this bending base material manufacturing method, the peripheral edge portion of the preform base material that hangs down due to its own weight is formed by the guide portions of the guide members provided at opposing positions across the molding surface in the direction in which the preform base material is bent. The preform base material can be accurately positioned on the molding surface by being smoothly guided toward the peripheral edge of the surface.

(3) The method for manufacturing a bent base material according to (1) or (2), wherein the corners of the peripheral portion of the preform base material are chamfered in advance.
According to this bending base material manufacturing method, by chamfering the corners of the peripheral edge of the preform base material in advance, the peripheral edge of the preform base material can be smoothly slid on the guide part of the guide member. Thereby, the peripheral portion of the preform base material is smoothly guided to the edge portion of the molding surface by the guide portion.

(4) Manufacturing a bent base material according to any one of (1) to (3), wherein the guide portion of the guide member has a coefficient of static friction of 0.5 or less at the temperature in the molding step. Method.
According to this bending base material manufacturing method, by setting the static friction coefficient of the guide portion of the guide member to 0.5 or less at the temperature in the molding process, the peripheral edge portion of the preform base material with respect to the guide portion of the guide member can slide well. Thereby, the peripheral portion of the preform base material is smoothly guided to the edge portion of the molding surface by the guide portion.

(5) The method of manufacturing a bent base material according to any one of (1) to (4), wherein the preform base material is formed to have an outer shape when the bent base material is flattened.
According to this bending base material manufacturing method, when the preform base material is molded into the bending base material, the molded bending base material can have an accurate target outer shape.

(6) In the molding step, after the preform base material is aligned along the molding surface, a suction step is performed in which the preform base material is attracted to the molding surface by suction from suction holes provided in the molding surface. , (1) to (5), the method for producing a bent base material.
According to this bending base material manufacturing method, the preform base material is reliably adhered to the molding surface by the suction step. As a result, the molding accuracy can be further increased, and the quality can be improved.

(7) The method of manufacturing a bent base material according to any one of (1) to (6), wherein a straight portion capable of engaging the edge of the preform base material is provided at the base of the guide member.
According to this bending base material manufacturing method, a part of the peripheral portion of the preform base material is engaged with the straight portion of the guide member in the molding process. As a result, even if the preform base material hangs down obliquely due to the deviation of the center of gravity or the inclination when placed, the lower edge portion is locked by the straight portion, and then the other portion of the peripheral edge portion is held by the guide member. is guided by the guide portion and positioned on the molding surface. Thereby, the preform base material can be reliably positioned on the molding surface.

(8) As the guide member, a pin-shaped guide member whose cross-sectional area increases downward is provided in the molding die, and the linear guide portion of the guide member guides the peripheral edge of the preform base material. The method for producing a bent base material according to any one of (1) to (7), wherein the parts are brought into point contact.
According to this bending base material manufacturing method, the peripheral edge of the preform base material is accurately guided to the edge of the forming surface while being brought into point contact with the linear guide portion of the pin-shaped guide member.

(9) As the guide member, a block-shaped guide member whose cross-sectional area increases downward is provided in the molding die, and the guide portion formed in the planar shape of the guide member has a peripheral edge of the preform base material. The method for producing a bent base material according to any one of (1) to (7), wherein the parts are brought into line contact.
According to this bending base material manufacturing method, the periphery of the preform base material is accurately guided to the edge of the forming surface while being in line contact with the planar guide portion of the block-shaped guide member.

(10) The method for producing a bent base material according to any one of (1) to (9), wherein the preform base material is formed from a glass plate.
According to this bending base material manufacturing method, by forming the preform base material from a glass plate, it is possible to easily form a high-quality bending base material made of a glass plate at least partially curved.

(11) A mold that molds a preform base material into a bent base material that is at least partially curved along a molding surface of the mold,
the molding surface having the same outline as the curved base material;
a guide member having a guide portion inclined from the outside of the molding surface toward the edge of the molding surface;
with
The guide member guides the peripheral portion of the preform base material toward the edge portion of the molding surface by causing the peripheral portion of the preform base material to contact and slide on the guide portion.
Forming mold for bending base material.
According to this bent base material forming die, a high-quality bent base material having at least a portion thereof curved can be easily formed by hanging the preform base material along the molding surface. Moreover, when the preform base material is formed into the bent base material by its own weight, the guide portion of the guide member guides the peripheral edge portion of the preform base material toward the peripheral edge of the molding surface. A preform base material can be accurately positioned on a molding surface having an outer shape. As a result, complicated post-processing such as grinding after molding to finish the outer shape to the final shape can be eliminated. In this way, the mold can position the preform base material on the molding surface of the mold with high accuracy and easily form a high-quality bent base material.

(12) The mold for bending base material according to (11), wherein the guide portion has a surface roughness of 50 nm to 1000 nm.
According to this bent base material mold, the contact surface with the preform base material maintains a certain level of surface strength, and the real contact surface with the preform base material is reduced to reduce the resistance due to friction, thereby reducing the preform. Local deformation of the substrate can be prevented.

(13) The mold for bending base material according to (11) or (12), wherein the guide portion has an inclination angle of 45° to 89°.
According to this bent base material molding die, the normal stress between the preform base material and the guide portion during molding is reduced to reduce frictional force, suppress local deformation of the preform base material, and prevent the preform base material from It is possible to prevent local deformation caused by finally riding on the guide portion.

(14) According to any one of (11) to (13), the guide portion has a coefficient of static friction of 0.5 or less at a molding temperature when molding the preform base material into the bent base material. Forming mold for bending base material.
According to this bent base material mold, local deformation of the preform base material due to contact resistance with the guide portion can be suppressed.

(15) The mold for a bent base material according to (14), wherein the static friction coefficient of the guide portion is 0.01 or more and 0.5 or less.
According to this bent base material molding die, local deformation of the preform base material due to contact resistance with the guide portion is suppressed, and the position of the preform base material does not shift significantly when the preform base material is initially set. can be made
(16) At least one side of the peripheral portion of the bent base material which is at least partially curved is R-chamfered, the shape tolerance of the chamfered cross-sectional shape is ±0.1 mm or less, and the outer dimensional accuracy of the peripheral portion is ±0. A bent substrate that is 2 mm or less.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
This application is based on Japanese Patent Application No. 2017-217135 filed on November 10, 2017, the contents of which are incorporated herein by reference.

10 bent base material 10P preform base material 13 corner portion 30 mold 31 molding surface 32 suction hole 50 guide member 51 straight portion 53 guide portion 70 guide member 71 straight portion 73 guide portion

Claims (15)

A manufacturing method for molding a preform substrate along a molding surface of a mold into a curved substrate having at least a portion thereof curved,
Of the vertical directions at any point on the molding surface, if the direction in which the preform base material curves during molding is downward, the opposite direction is upward, and the other than the molding surface in top view is outside,
a base material placing step of placing the preform base material from above the molding surface having the same outer shape as that of the bent base material;
a molding step of heating and softening the preform base material so that the preform base material is formed into the bent base material along the molding surface by its own weight,
In the base material placing step, placing the preform base material on a mold having a guide member having a guide portion inclined from the outside of the molding surface toward the edge of the molding surface,
In the molding step, the peripheral edge portion of the preform substrate is brought into contact with the guide portion and slid to guide the peripheral edge portion of the preform substrate toward the edge portion of the molding surface. Production method. 2. The method of manufacturing a bent base material according to claim 1, wherein the guide members are provided at opposing positions across at least the molding surface. 3. The method of manufacturing a bent base material according to claim 1, wherein the corners of the periphery of the preform base material are chamfered in advance. The method for manufacturing a bent base material according to any one of claims 1 to 3, wherein the guide portion of the guide member has a coefficient of static friction of 0.5 or less at the temperature in the molding step. The method for manufacturing a bent base material according to any one of claims 1 to 4, wherein the preform base material is formed to have an outer shape when the bent base material is flattened. 3. A suction step is performed in which, after the preform base material is aligned along the molding surface in the molding step, the preform base material is attracted to the molding surface by suction from suction holes provided in the molding surface. 6. The method for producing a bendable base material according to any one of 1 to 5. The method for manufacturing a bent base material according to any one of claims 1 to 6, wherein a straight portion capable of engaging the edge of the preform base material is provided at the base of the guide member. As the guide member, a pin-shaped guide member whose cross-sectional area increases downward is provided in the molding die, and the peripheral edge of the preform base material is pointed at the linearly formed guide portion of the guide member. The method for producing a bendable base material according to any one of claims 1 to 7, wherein the substrates are brought into contact with each other. As the guide member, a block-shaped guide member whose cross-sectional area increases downward is provided in the molding die, and the peripheral edge of the preform base material is drawn along the guide portion formed in the planar shape of the guide member. The method for producing a bendable base material according to any one of claims 1 to 7, wherein the substrates are brought into contact with each other. The method for producing a bent base material according to any one of claims 1 to 9, wherein the preform base material is formed from a glass plate. A mold that molds a preform base material into a curved base material that is at least partially curved along a molding surface of the mold,
the molding surface having the same outline as the curved base material;
a guide member having a guide portion inclined from the outside of the molding surface toward the edge of the molding surface;
with
The guide member guides the peripheral portion of the preform base material toward the edge portion of the molding surface by causing the peripheral portion of the preform base material to contact and slide on the guide portion.
Forming mold for bending base material. 12. The mold for a bent base material according to claim 11, wherein the guide portion has a surface roughness of 50 nm to 1000 nm. The mold for a bent base material according to claim 11 or 12, wherein the guide portion has an inclination angle of 45° to 89°. The bending base material according to any one of claims 11 to 13, wherein the guide part has a static friction coefficient of 0.5 or less at a molding temperature when the preform base material is molded into the bending base material. molding mold. 15. The mold for a bent base material according to claim 14, wherein the static friction coefficient of the guide portion is 0.01 or more and 0.5 or less.

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