JP7211424B2 - Mold for molding 3D cover glass and method for manufacturing 3D cover glass using the same - Google Patents

Description

The present invention is a three-dimensional cover glass (3D cover glass) for image display devices used in mobile devices such as mobile phones, smartphones, and tablet terminals, CID (Center Information Display), and in-vehicle displays such as clusters. The present invention relates to a molding die and a method for manufacturing a 3D cover glass using the molding die.

In order to improve the design of mobile devices such as mobile phones, smart phones, and tablet terminals, the application of 3D cover glass to image display devices used in mobile devices and the like is being studied. FIG. 1 is a perspective view showing a conventional 3D cover glass. The 3D cover glass 300 shown in FIG. 1 has a flat central portion 310 and a curved surface portion 320 around the central portion 310 having a three-dimensional curved surface shape. Hereinafter, in the present specification, when describing a curved surface portion of a 3D cover glass, it refers to a curved surface portion having a three-dimensional curved surface shape.

Patent Literature 1 discloses a method for forming a so-called 3D cover glass having curved ends as a cover glass for an information terminal such as a smart phone. Patent Document 1 discloses a mold designed for 3D cover glass, and a desired 3D cover glass is realized by a molding method in which a hole is provided in a part of the mold and vacuum is drawn.

U.S. Patent Application Publication No. 2017/121210

The 3D cover glass may be required to have a design in which the bending angle of the curved surface portion exceeds 90°. FIG. 2 is a perspective view showing one configuration example of the 3D cover glass. The 3D cover glass 100 shown in FIG. 2 has a central portion 110 that is flat and has a curved surface portion 120 around the central portion 110 with a bending angle exceeding 90°. The bending angle of the curved surface portion of the 3D cover glass will be described with reference to FIG. FIG. 3 is a schematic cross-sectional view of the 3D cover glass 100 shown in FIG.
The bending angle α of the curved surface portion is an angle formed by a plane parallel to the plane of the central portion 110 of the 3D cover glass and the tip of the curved surface portion 120 . That is, the angle formed by the tangent line at a point on the curved surface portion 120 and the plane parallel to the plane of the center portion 110 of the 3D cover glass is the angle from the center portion 110 of the 3D cover glass toward the tip of the curved surface portion 120. The value (maximum angle) at which this angle becomes maximum corresponds to the bending angle α. The 3D cover glass 100 shown in FIGS. 2 and 3 is an example with a bending angle α of 180°.

When molding a 3D cover glass in which the bending angle α of the curved surface portion exceeds 90° using a mold, the portion corresponding to the curved surface portion of the mold also has a curved surface shape with an angle exceeding 90°. There was a problem that the glass after molding could not be taken out. In addition, the portion where the bending angle α exceeds 90° and the outer edge forms a curved surface in plan view forms a more complicated three-dimensional shape, so it is difficult to realize a three-dimensional shape with high accuracy. rice field.

In order to solve the above problems, the present invention provides a mold for molding 3D cover glass having a curved surface portion with a bending angle α exceeding 90 ° and a method for manufacturing 3D cover glass using the mold. With the goal.

In order to achieve the above objects, it has a main molding die for forming a 3D cover glass,
The main molding die has a center portion with a radius of curvature of more than 100 mm and a curved surface portion forming a three-dimensional curved surface at least partly around the center portion, and a recess is formed by the center portion and the curved surface portion. is,
At least part of the curved surface portion has a tangent angle that is continuous to more than 90° and 180° or less with respect to the plane formed by the central portion,
In addition, the curved surface portion where the angle of the tangent continues to more than 90° and 180° or less connects two adjacent sides of the outer edge of the recess when viewed from the normal direction of the center portion, and has a radius of curvature. is formed in at least one corner defined by 100 mm or less,
The corner has a groove that continues from the position where the angle of the tangent is maximum to the end of the center,
Furthermore, the main molding die has a through hole connected to the groove,
divisible in a direction parallel to the plane of the central portion;
Provide a mold for 3D cover glass molding.

Further, in the 3D cover glass molding mold, the main molding mold has a polygonal outer edge of the recess when viewed from the normal direction of the center,
It is preferable that the curved surface portion where the tangent angle is continuous from more than 90° to 180° or less is formed along the entire circumference of the polygon, and that all the corners of the polygon have the grooves.

Moreover, in the mold for molding a 3D cover glass, the polygon is preferably a quadrangle.

Further, in the mold for molding a 3D cover glass, the main mold has a surface parallel to the plane of the central portion along the outside from the end portion where the angle of the tangent line is the largest among the curved surface portions. It is preferable to have an inclined portion with an inclination of 3° to 30° with respect to .

Further, in the mold for molding 3D cover glass, the width of the inclined portion is preferably 1 mm to 15 mm in plan view.

Further, in the 3D cover glass molding mold, the main molding mold is composed of a plurality of partial molds, and among the curved surface portions formed over the entire circumference of the polygon, on the sides of the polygon It is preferable that there is no parting line corresponding to the boundary where the mold parts are adjacent to each other.

In addition, the 3D cover glass forming mold further has a bottom mold on the side of the main forming mold that does not have the recess,
It is preferable that the bottom mold has a suction hole at a position including the center of gravity of the central portion, and the suction hole is connected to the through hole.

Further, the 3D cover glass forming mold further has a ring-shaped alignment plate on the side of the main forming mold having the recess,
It is preferable that the ring-shaped inner edge of the alignment plate is located outside the outer edge of the recess in plan view.

Moreover, it is preferable that the 3D cover glass forming mold further includes an upper mold for covering the main forming mold on the side of the main forming mold having the concave portion.

In addition, placing a flat glass plate on the main molding die of the 3D cover glass molding die of the present invention, and then heating the 3D cover glass molding die while heating the through hole forming the planar glass plate into a 3D shape by vacuum suction through and then cooling.

Further, in the method for manufacturing a 3D cover glass of the present invention, after the cooling, the 3D cover glass is taken out from the 3D cover glass molding die, and the bottom portion outside the curved surface portion of the 3D cover glass is cut. is preferred.

Further, the method for manufacturing a 3D cover glass of the present invention preferably includes polishing the surface of the 3D cover glass after the cutting, and then chemically strengthening the 3D cover glass.

INDUSTRIAL APPLICABILITY The mold for molding 3D cover glass of the present invention and the method for producing 3D cover glass using the mold are suitable for producing 3D cover glass having a curved portion with a bending angle α exceeding 90°.

FIG. 1 is a perspective view showing a conventional 3D cover glass. FIG. 2 is a perspective view showing one configuration example of the 3D cover glass. FIG. 3 is a schematic cross-sectional view of the 3D cover glass shown in FIG. FIG. 4 is an exploded perspective view showing one configuration example of a mold for molding a 3D cover glass according to an embodiment of the present invention. 5 is a partially enlarged view of the mold for molding the 3D cover glass shown in FIG. 4. FIG. FIG. 6 is an assembly diagram of the mold for molding the 3D cover glass shown in FIG. 7 is a cross-sectional view of the mold for molding the 3D cover glass shown in FIG. 6 at cross-section A. FIG. 8 is a cross-sectional view of the mold for molding the 3D cover glass shown in FIG. 6 at the cross-section B. FIG. FIG. 9 is a diagram for explaining the procedure for using the mold for molding the 3D cover glass. FIG. 10 is a diagram for explaining the procedure for using the mold for molding the 3D cover glass. FIG. 11 is a diagram for explaining the procedure for using the mold for molding the 3D cover glass. FIG. 12 is a diagram for explaining the procedure for using the mold for molding the 3D cover glass. FIG. 13 is a diagram for explaining the procedure for using the mold for molding the 3D cover glass. FIG. 14 is a diagram for explaining the procedure for using the mold for molding the 3D cover glass. FIG. 15 is a diagram for explaining the procedure for using the mold for molding the 3D cover glass. FIG. 16 is a diagram for explaining the procedure for using the mold for molding the 3D cover glass.

The present invention will now be described with reference to the drawings.
A mold for molding a 3D cover glass according to an embodiment of the present invention (hereinafter referred to as "a mold for molding a 3D cover glass of the present embodiment") is, like the 3D cover glass 100 shown in FIGS. 110 is a flat surface, and a molding die used for molding a 3D cover glass having a curved surface portion 120 with a bending angle α of more than 90° and less than or equal to 180° around the central portion 110 . However, the 3D cover glass molded by the mold for molding 3D cover glass of the present embodiment has a flat central portion, and at least a part of the periphery of the central portion has a curved surface with a bending angle α of more than 90° and 180° or less. It is not limited to those shown in FIGS. 2 and 3 as long as it has parts.
Here, a plane refers to a portion with a radius of curvature greater than 100 mm. That is, the central portion of the 3D cover glass glass is a continuous region containing the center (center of gravity) of the 3D cover glass glass and having a radius of curvature greater than 100 mm.
In addition, the curved surface portion refers to a portion having a radius of curvature of 100 mm or less in a cross section perpendicular to the plane of the central portion 110, and a portion including the portion and the end portion of the 3D cover glass. That is, the area from the outer edge of the central portion 110 to the edge of the 3D cover glass is the curved portion. The radius of curvature of the curved portion may not be constant, and the curved portion may include relatively flat portions. The term “curved surface portion” without specifying the bending angle includes both curved surface portions with a bending angle of more than 90° and 180° or less and curved surface portions with a bending angle of 90° or less.
The bending angle α of the curved surface portion is an angle formed between a plane in contact with the center of gravity of the central portion 110 of the 3D cover glass and the tip of the curved surface portion 120 . More specifically, in the cross section orthogonal to the plane of the central portion 110, the edge of the 3D cover glass is point A, the center of gravity of the 3D cover glass is point B, and the intersection of the tangent line at point A and the tangent line at point B is point C , the bending angle is expressed by 180°-∠ACB.

In the 3D cover glass 100 shown in FIG. 2, the curved surface portion 120 is provided over the entire periphery of the central portion 110, but the 3D cover glass molded by the 3D cover glass molding die of the present embodiment is Any two of the four sides of the shape drawn by the outer edge and at least one corner connecting the two sides have a curved surface portion, and at least a part of the curved surface portion has a bending angle α of more than 90 ° 180 ° or less.
In this specification, unless otherwise specified, the term “planar view” refers to a viewpoint from a normal direction to a plane in contact with the center of gravity of the 3D cover glass, or to the center of gravity of the mold described later. A viewpoint from a normal direction to a tangent plane will be described. Further, in this specification, the shape drawn by the outer edge in plan view may be simply referred to as "planar shape".
In this specification, the term “corner” is a concept that refers to a portion that connects two adjacent sides, and not only a corner portion but also a rounded portion, that is, a curved portion that connects two adjacent sides. It is a concept that also includes the part of

For example, in FIG. 2, the 3D cover glass 100 has a substantially rectangular planar shape and has four sides and four corners, all of which have a bending angle α of more than 90° and 180° or less. However, the 3D cover glass molded by the 3D cover glass molding mold of this embodiment has four sides, and only two adjacent sides and one corner connecting the two sides are bent. You may have a curved surface part with angle (alpha) exceeding 90 degrees and 180 degrees or less. The corner portion refers to a portion having an outer edge with a radius of curvature of 100 mm or less when viewed from the normal direction of the central portion.

Furthermore, the 3D cover glass molded by the mold for molding the 3D cover glass of the present embodiment includes any three of the four sides and at least one corner connecting any two adjacent sides of the three sides. The portion may have a curved surface portion with a bending angle α of more than 90° and less than or equal to 180°.

Further, the 3D cover glass 100 shown in FIG. 2 is provided with a curved surface portion 120 having a bending angle α of more than 90° and less than or equal to 180° over the entire circumference of the central portion 110 . However, not limited to this example, the 3D cover glass molded by the 3D cover glass molding die of this embodiment has a bending angle α of 90° at least one corner connecting any two of the four sides. You may have a curved surface part of more than 180 degrees or less.

In addition, the 3D cover glass molded by the 3D cover glass molding die of the present embodiment has one corner connecting any two adjacent sides among the four sides, and one side of the two sides Only the curved surface portion having a bending angle α of more than 90° and 180° or less may be provided.

In addition, the 3D cover glass 100 molded by the 3D cover glass molding die of the present embodiment is bent only at two adjacent sides and one corner connecting the two sides among the four sides. You may have a curved surface part with angle (alpha) exceeding 90 degrees and 180 degrees or less.

In addition, the 3D cover glass 100 molded by the 3D cover glass molding die of the present embodiment includes one corner connecting any two adjacent sides among the four sides, and an adjacent side different from the two sides. Only one corner connecting two arbitrary sides may have a curved surface portion with a bending angle α of more than 90° and less than or equal to 180°.

In addition, the 3D cover glass 100 molded by the 3D cover glass molding die of the present embodiment has two corners connecting three sides among the four sides, and only one side of the three sides. Alternatively, only two sides may have a curved surface portion with a bending angle α of more than 90° and less than or equal to 180°.

In addition, the 3D cover glass 100 molded by the mold for molding the 3D cover glass of the present embodiment has two corners connecting three sides among the four sides, and only the three sides have a bending angle α of 90. You may have a curved-surface part more than degree and 180 degrees or less.

In addition, the 3D cover glass 100 molded by the mold for molding the 3D cover glass of the present embodiment has a curved surface portion with a bending angle α of more than 90° and 180° or less only at any three corners. good.

In addition, the 3D cover glass 100 molded by the 3D cover glass molding die of the present embodiment has any three corners and only one of the four sides, only two sides, or three corners. Only the sides may have a curved surface portion with a bending angle α of more than 90° and less than or equal to 180°.

In addition, the 3D cover glass 100 molded by the mold for molding the 3D cover glass of the present embodiment has arbitrary three corners and curved surface portions with a bending angle α of more than 90° and 180° or less only on four sides. You may

Further, the 3D cover glass 100 molded by the mold for molding the 3D cover glass of the present embodiment may have curved surface portions with a bending angle α of more than 90° and less than or equal to 180° only at four corners.

In addition, the bending angle of the curved surface portion other than the curved surface portion for which the angle α is specified as more than 90° and 180° or less is 90° or less.

In addition, although the 3D cover glass shown in FIG. 2 has a quadrangular planar shape, the planar shape of the 3D cover glass molded by the mold for molding the 3D cover glass of the present embodiment is not limited to a quadrilateral. Polygons other than squares, such as pentagons, hexagons, and octagons, may also be used. The term “polygon” as used herein includes those having rounded corners. In other words, even if the planar shape of the 3D cover glass includes curved portions at the corners, the shape obtained by the straight line and the virtual straight line extending the straight line is polygonal. If so, it is considered a "polygon" object. In addition, when the planar shape of the 3D cover glass is a polygon and the entire circumference has a curved surface, all the corners of the polygon often have rounded portions. Also in the case of a polygonal shape in plan view, the "corner" is defined as a portion having an outer edge with a radius of curvature of 100 mm or less when viewed from the normal direction of the central portion, similarly to the above.
Moreover, the 3D cover glass molded by the mold for molding the 3D cover glass of the present embodiment may have a planar shape having at least one corner connecting two straight lines.

FIG. 4 is an exploded perspective view showing one configuration example of the 3D cover glass molding die of this embodiment, and FIG. 5 is a partially enlarged view of the 3D cover glass molding die shown in FIG. FIG. 6 is an assembly diagram of the mold for molding the 3D cover glass shown in FIG. 7 is a cross-sectional view of the mold for forming the 3D cover glass shown in FIG. 6 at the cross-section A, and FIG. 8 is a cross-sectional view of the mold for forming the 3D cover glass shown in FIG. 6 at the cross-section B.

The 3D cover glass molding mold in the configuration examples shown in FIGS. 4 to 8 has a main molding mold 20, a bottom mold 30, an upper mold 40 and an alignment plate 50, 100 molding can be used. However, in the 3D cover glass molding mold of this embodiment, only the main molding mold 20 is an essential component, and as described later, if the glass can be molded by vacuum suction, the bottom mold 30 and the upper mold 40 and alignment plate 50 are optional components.

(mold for main molding)
The main mold 20 has a flat center portion 21 and a curved surface portion 22 forming a three-dimensional curved surface around the center portion 21 . A concave portion 23 is formed by the central portion 21 and the curved surface portion 22 . Hereinafter, in this specification, when the curved surface portion of the main molding die is described, it means a curved surface portion having a three-dimensional curved surface shape. Flat here means that the radius of curvature is greater than 100 mm. That is, the central portion of the main molding die is a continuous region including the center of the recess and having a radius of curvature greater than 100 mm. The center of the main molding die molds the center of the 3D cover glass.
In addition, the curved surface portion refers to a portion having a curvature radius of 100 mm or less in a cross section perpendicular to the plane of the center portion 21 of the main molding die 20, and a portion including the area between the portion and the end portion 28. . That is, the area from the outer edge of the central portion 21 to the end portion 28 is the curved surface portion. The radius of curvature of the curved portion may not be constant, and the curved portion may include relatively flat portions. The curved surface portion of the main molding die forms the curved surface portion of the 3D cover glass.
In addition, in this specification, when referring to the angle of the tangent when the curved surface of the main molding die is based on the plane of the center, the angle formed by the plane in contact with the center of the center and the tangent to the curved surface is. More specifically, the tangent angle with respect to the plane of the central part is the point A on the curved surface in the cross section perpendicular to the plane of the central part of the main molding die, and the center of the central part is the point B, and the intersection of the tangent line at the point A and the tangent line at the point B is the point C, the bending angle is expressed by 180°-∠ACB. Also, the angle when the point A is the edge is the "maximum angle of the tangent line with respect to the central plane".
In addition, when simply referring to a "curved surface portion" without specifying the bending angle, the curved surface portion with the maximum angle of the tangent line with respect to the plane of the central portion being more than 90° and 180° or less, and the curved surface portion with 90° or less includes both

The illustrated main mold 20 has a curved portion 22 around the entire periphery of a central portion 21 . However, not limited to this example, the main molding die of the 3D cover glass molding die of this embodiment includes any two sides of the four sides of the planar shape of the recess and at least one side connecting the two sides It is sufficient that the corner portion has a curved surface portion with a maximum tangent angle of more than 90° and less than or equal to 180° with respect to the plane of the central portion 21 .

For example, the main molding die of the 3D cover glass molding die of the present embodiment has two adjacent sides and one corner connecting the two sides among the four sides in the planar shape of the recess. Only, the curved surface portion may have a maximum tangent angle of more than 90° and less than or equal to 180° with respect to the plane of the central portion 21 .

Furthermore, the main molding die of the 3D cover glass molding die of the present embodiment connects any three sides of the four sides in the planar shape of the recess and any two adjacent sides among the three sides At least one corner may have a curved surface portion with a maximum tangent angle of more than 90° and less than or equal to 180° with respect to the plane of the central portion 21 .

In the 3D cover glass 100 shown in FIGS. 2 and 3, the curved surface portion 120 has a bending angle α of 180°. is continuous up to 180°. However, the curved surface portion of the main molding mold of the 3D cover glass molding mold of the present embodiment is bent with respect to the center plane according to the bending angle of the curved surface portion of the 3D cover glass to be molded. It is sufficient that the tangent angle is continuous from more than 90° to 180° or less. Hereinafter, a curved surface portion where the tangent angle is continuous from 90° to 180° with respect to the central plane is referred to as a curved surface portion having a maximum tangent angle of more than 90° to 180°. do.

In addition, in the main molding die of the 3D cover glass molding die of the present embodiment, at least one corner connecting two straight lines on the outer edge of the recess in plan view is aligned with the plane of the center portion 21. It is sufficient that the curved surface portion has a maximum tangential angle of more than 90° and less than or equal to 180° with respect to the reference. In addition, in the main molding die, the corner portion refers to a portion having a radius of curvature of 100 mm or less on the outer edge of the concave portion in plan view. The linear portion refers to a portion having a radius of curvature of more than 100 mm on the outer edge of the concave portion in plan view. The outer edge of the recess 23 corresponds to the outermost portion of the recess in plan view. Therefore, the outer edge of the recess in plan view means that when the curved surface portion 22 has a maximum tangent angle of more than 90° with respect to the plane of the central portion 21 of the main molding die 20, the tangent angle is It corresponds to a line formed by connecting positions at 90°.

For example, in the recess 23 of the main molding die 20 in this embodiment, only one corner connecting any two adjacent sides among the four sides is tangent to the plane of the central part 21 may have a curved surface portion with a maximum angle of more than 90° and 180° or less.

In addition, the concave portion 23 of the main molding die 20 in this embodiment has one corner connecting any two adjacent sides among the four sides, and the central portion 21 only on one of the two sides. may have a curved surface portion with a maximum tangent angle of more than 90° and less than or equal to 180° with respect to the plane of .

In addition, the concave portion 23 of the main molding die 20 in the present embodiment has four sides, any two adjacent sides and only one corner connecting the two sides with respect to the plane of the central portion 21. The curved surface portion may have a maximum tangent angle of more than 90° and less than or equal to 180°.

In addition, the concave portion 23 of the main molding die 20 in the present embodiment has one corner portion that connects any two adjacent sides among the four sides, and any two adjacent sides that are different from the two sides. Only one corner portion may have a curved surface portion with a maximum tangent angle of more than 90° and 180° or less with respect to the plane of the central portion 21 .

In addition, the recess 23 of the main molding die 20 in this embodiment has two corners connecting three of the four sides and a central part only on one or two of the three sides. A curved surface portion having a bending angle α of more than 90° and less than or equal to 180° with respect to the plane of 21 may be provided.

In addition, the concave portion 23 of the main molding die 20 in this embodiment has two corners connecting three sides among the four sides, and only the three sides have the plane of the center portion 21 as a reference. The curved surface portion may have a maximum tangent angle of more than 90° and less than or equal to 180°.

In addition, the concave portion 23 of the main molding die 20 in this embodiment has a curved surface with a maximum tangent angle of more than 90° and 180° or less with respect to the plane of the central portion 21 only at arbitrary three corners. may have a part.

In addition, the concave portion 23 of the main molding die 20 in this embodiment has three arbitrary corners and only one side (or two sides, or three sides) of the four sides, the plane of the central portion 21. may have a curved surface portion with a maximum tangent angle of more than 90° and less than or equal to 180° with respect to .

In addition, in the concave portion 23 of the main molding die 20 in this embodiment, the maximum angle of the tangent to the plane of the central portion 21 is greater than 90° and 180° only at any three corners and four sides. ° or less.

In addition, the concave portion 23 of the main molding die 20 in the present embodiment has curved portions with a maximum angle of tangent to the plane of the central portion 21 of more than 90° and 180° or less only at the four corners. may have.

The curved surface portions other than the curved surface portions having the maximum tangent angle of more than 90° and 180° or less with respect to the plane of the central portion 21 specified above have the maximum tangent angle of 90° or less.

In the illustrated main molding die 20, the outer edge of the recess 23 in plan view is quadrangular, but the outer edge shape of the recess in plan view of the main molding die in the present embodiment is not limited to a quadrangle, and is triangular. , pentagons, hexagons, octagons, and other polygons other than quadrilaterals may be used. The outer edge of the recess 23 corresponds to the outermost portion of the recess in plan view. For example, if the main molding die 20 has a curved surface portion 22 with a maximum tangent angle of more than 90° with respect to the plane of the central portion 21 over the entire circumference of the central portion 21, the tangent angle is 90°. A line formed by connecting the positions of ° over the entire circumference corresponds to the outer edge.

As shown in FIGS. 4 and 5, the corner portion 24 having the curved surface portion 22 with the maximum tangent angle of more than 90° and 180° or less with respect to the plane of the central portion 21 is located at the position where the tangent angle is maximum. to the end of the center portion 21 , and the groove 25 is connected to a through hole 26 of the main molding die 20 . The grooves 25 and the through-holes 26, as indicated by the arrows in FIG. 8, serve as paths for vacuum suction when forming the 3D cover glass. The mold for forming the 3D cover glass of this embodiment is provided with grooves 25 connected to through-holes 26 at the corners 24 where the glass follows the mold the slowest and is difficult to mold during vacuum suction. As a result, the glass can be molded while being reliably brought into close contact with the entire concave portion of the main molding die including the corner portions.

The main molding die 20 shown in FIG. 4 has a curved surface portion 22 with a maximum tangent angle of more than 90° and 180° or less with respect to the plane of the center portion 21 over the entire periphery of the center portion 21. Therefore, in the figure, all four corners are provided with grooves extending from the position where the tangent angle is maximum to the end of the central part 21, and through holes connecting with the grooves. .
In FIG. 5, one groove 25 is provided at one corner, but two or more grooves may be provided at one corner. In that case, the groove may have a structure in which one path branches into a plurality of paths, or may have a structure in which a plurality of grooves are provided independently.

Further, the main molding die 20 can be divided in a direction parallel to the plane of the central portion 21, as shown in FIG. By dividing the main molding die 20 in a direction parallel to the plane of the central portion 21, after molding a 3D cover glass having a bending angle α of the curved surface portion of more than 90 ° and 180 ° or less, the 3D cover glass can be easily formed. I can take it out. In addition, the divisible main molding die 20 has a dividing line corresponding to a boundary formed by adjacent partial molds when a plurality of partial molds are assembled.

Preferred conditions for the position of the parting line in the main molding die will be described below.
First, the case where the parting line cannot be arranged while avoiding the curved surface portion of the main molding die will be described. For example, like the main molding die 20 shown in FIG. 4, when the curved surface portion is provided all around the central portion, the parting line cannot be arranged while avoiding the curved surface portion.
In this case, it is preferable to arrange the parting lines while avoiding the straight parts of the curved surface, that is, to arrange the parting lines at the center and at the corners of the curved surface. The reason why it is preferable to arrange the parting line in the center part is that even if the parting line is transferred to the center part of the 3D cover glass, it can be easily repaired by grinding and polishing. In addition, it is preferable to arrange the dividing line at the corner of the curved surface part because the corner part of the curved surface part of the 3D cover glass is unlikely to be used as a display part, and when it is used as a display part However, this is because the area is small and the defects due to transfer are not conspicuous.

Next, the case where the parting line can be arranged while avoiding the curved surface portion of the main molding die will be described. For example, in the case where curved portions are arranged only at the corners of the concave portion of the main molding die, the parting lines can be arranged while avoiding the curved portions.
In this case, it is preferable that the dividing line is provided only in the central portion. This is because even if the parting line is transferred to the center of the 3D cover glass, it can be easily repaired by grinding.

In addition, the main molding die 20 is inclined at an angle of 3° to 30° with respect to a plane parallel to the plane of the central portion 21 along the outer side from the end portion 28 where the tangent angle of the curved surface portion 22 is maximum. It is preferable to have an inclined portion 27 forming a The 3D cover glass after molding may have a skirt portion (the portion that is finally removed) on the outside of the curved surface portion. The edge 28 of the curved surface 22 of the mold 20 may be caught, making it difficult to remove the 3D cover glass. However, by providing the inclined portion 27 as described above, the occurrence of this pinching is suppressed, so that the 3D cover glass after molding can be easily taken out. Also, the inclination of the inclined portion 27 is preferably 4° to 25°, more preferably 5° to 20°, with respect to a plane parallel to the plane of the central portion 21 . The width of the inclined portion may be 1 mm to 15 mm in plan view, preferably 2 mm to 10 mm.

(bottom type)
The bottom mold 30 is arranged on the side of the main molding die 20 that does not have a recess. The bottom mold 30 has a stepped portion 31 at its center that is lower than the periphery, and has a suction hole 32 at a position that includes the center of gravity of the stepped portion 31 . As shown in FIGS. 7 and 8, the suction hole 32 is connected to the through hole 26 of the main molding die 20 via the stepped portion 31, and when molding the 3D cover glass, the main molding die The groove 25 of 20, the through hole 26, the stepped portion 31 of the bottom mold 30, and the hole 32 for suction constitute a vacuum suction path.

However, the suction holes in the bottom mold are not limited to the illustrated arrangement. For example, the bottom mold may not have a stepped portion at its center and may have suction holes directly below the through holes of the main molding die, that is, at the four corners of the bottom mold.
Further, the mold for molding the 3D cover glass may not have a bottom mold. In this case, the vacuum is directly sucked from the through hole of the main molding die. However, if the bottom mold is provided, the vacuum suction paths can be concentrated in one place. Therefore, there is only one joint between the equipment and the mold, and there is only one structure for vacuum suction on the equipment side. Therefore, equipment can be simplified. In addition, since the mold has a structure in which a vacuum chamber exists, uniform vacuum suction is possible.

(upper die)
The upper mold 40 is arranged on the side of the main molding die 20 having the concave portion 23 . The mold for molding the 3D cover glass of this embodiment does not have to have an upper mold, but if the main mold 20 is covered with the upper mold 40, the glass can be efficiently heated from above and below. Therefore, temperature difference is less likely to occur in the thickness direction of the glass, and thermal deformation during heating can be suppressed. Furthermore, at the timing of vacuum suction, the edge of the glass may jump up in the direction opposite to the vacuum suction direction due to the reaction force, breaking the vacuum. can be suppressed. Therefore, if there is an upper mold, vacuum suction can be performed more effectively when molding the 3D cover glass. The upper mold 40 preferably has a structure that completely covers the upper surface of the main molding die 20 .

(Alignment plate)
The ring-shaped alignment plate 50 is arranged on the side of the main molding die 20 having the concave portion 23 . The ring-shaped inner edge of the alignment plate 50 is outside the outer edge of the recess 23 of the main molding die 20 in plan view. The mold for molding the 3D cover glass of this embodiment may not have an alignment plate, but by arranging the alignment plate 50, when molding the 3D cover glass, the This facilitates positioning when the flat glass plate 200 is placed. In other words, the provision of the alignment plate 50 has the effect of stabilizing the variation in positioning, thereby improving the yield during mass production.

An example of the procedure for using the mold for molding the 3D cover glass of this embodiment will be described with reference to FIGS. 9 to 16. FIG.
9 is a plan view of the bottom mold 30. FIG. FIG. 10 is a plan view of the main molding die 20. FIG. In the example of FIG. 10, the main molding die 20 has a structure that is divided into four partial dies so that each of the four corners has a boundary line. As shown in FIG. 11, when the main molding die 20 is assembled on the bottom die 30, they are integrated with a dividing line at the boundary formed by the partial dies. Next, as shown in FIG. 12, the alignment plate 50 is placed on the main molding die 20 . Next, as shown in FIG. 13, a flat glass plate 200 is placed on the main molding die 20 . Next, as shown in FIG. 14, the upper die 40 is fixed on the alignment plate 50 so as to cover the alignment plate 50 . In the state shown in FIG. 14, while heating the 3D cover glass molding die of this embodiment, the suction hole 32 of the bottom mold 30, the stepped portion 31, the through hole 26 of the main molding die 20, and the corner portion Vacuum is sucked through grooves 25 provided in 24 to form a flat glass plate into a 3D shape, and then cooled.

After cooling, the upper mold 40 is removed, the alignment plate 50 is removed, the mold for molding the 3D cover glass is turned upside down, the main mold 20 is taken out from the bottom mold 30, and the main mold 20 is removed. The 3D cover glass after molding is taken out by dividing in a direction parallel to the central part of the 3D cover glass.
FIG. 15 is a perspective view showing a state in which the glass plate 200 is placed on the main molding die 20 before molding the 3D cover glass, and FIG. It is a perspective view showing a state in which the .

The 3D cover glass after molding may have the skirt portion described above on the outer side of the curved surface portion. In that case, the skirt outside the curved portion of the formed 3D coverglass is cut to define a 3D coverglass having a predetermined shape. After that, the surface (flat surface, curved surface, end surface) of the 3D cover glass is subjected to chemical strengthening treatment by polishing or immersing it in a predetermined molten salt to perform ion exchange, so that the bending angle α A chemically strengthened 3D cover glass greater than 90° and less than or equal to 180° may be made.

Although the present invention has been described in detail 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 a Japanese patent application (Japanese Patent Application No. 2018-155423) filed on August 22, 2018, the entirety of which is incorporated by reference. Also, all references cited herein are incorporated in their entirety.

10: 3D cover glass molding mold 20: main molding mold 21: center part 22: curved surface part 23: concave part 24: corner part 25: groove part 26: through hole 27: inclined part 28: end part 30: bottom mold 31: stepped portion 32: hole for suction 40: upper die 50: alignment plate 100, 300: 3D cover glass 110, 310: central portion 120, 320: curved surface portion 122: end portion 200: glass plate

Claims (12)

having a main mold for forming the 3D cover glass,
The main molding die has a center portion with a radius of curvature of more than 100 mm and a curved surface portion forming a three-dimensional curved surface at least partly around the center portion, and a recess is formed by the center portion and the curved surface portion. is,
At least part of the curved surface portion has a tangent angle that is continuous to more than 90° and 180° or less with respect to the plane formed by the central portion,
In addition, the curved surface portion where the angle of the tangent continues to more than 90° and 180° or less connects two adjacent sides of the outer edge of the recess when viewed from the normal direction of the center portion, and has a radius of curvature. is formed in at least one corner defined by 100 mm or less,
The corner has a groove that continues from the position where the angle of the tangent is maximum to the end of the center,
Furthermore, the main molding die has a through hole connected to the groove,
divisible in a direction parallel to the plane of the central portion;
Mold for 3D cover glass molding. The main molding die has a polygonal outer edge of the recess when viewed from the normal direction of the center,
2. The curved surface portion where the angle of the tangent line is continuous from more than 90° to 180° or less is formed over the entire circumference of the polygon, and has the groove at all the corners of the polygon. 3D cover glass molding mold according to. 3. The mold for molding 3D cover glass according to claim 2, wherein the polygon is a quadrilateral. The main molding die has an inclination of 3° to 30° with respect to a plane parallel to the plane of the central portion along the outer side from the end of the curved surface portion where the angle of the tangent line is maximum. The mold for molding a 3D cover glass according to any one of claims 1 to 3, having an inclined portion. The mold for molding 3D cover glass according to claim 4, wherein the width of the inclined portion is 1 mm to 15 mm in plan view. The main molding die is composed of a plurality of partial dies,
4. The method according to claim 2 or 3 , wherein, of the curved surface portion formed over the entire circumference of the polygon, there is no parting line corresponding to a boundary between the mold parts adjacent to each other on a side of the polygon. 3D cover glass molding mold. A bottom mold is further provided on the side of the main molding die that does not have the recess,
3D according to any one of claims 1 to 6, wherein the bottom mold has a suction hole at a position including the center of gravity of the central part, and the suction hole is connected to the through hole. Mold for cover glass molding. further comprising a ring-shaped alignment plate on the side of the main molding die having the recess,
The mold for molding a 3D cover glass according to any one of claims 1 to 7, wherein the ring-shaped inner edge of the alignment plate is located outside the outer edge of the recess in plan view. The mold for molding a 3D cover glass according to any one of claims 1 to 8, further comprising an upper mold covering the main mold on the side of the main mold having the recess. Placing a planar glass plate on the main molding mold of the 3D cover glass molding mold according to any one of claims 1 to 9, and then the 3D cover glass molding mold A method for producing a 3D cover glass, comprising: forming the flat glass plate into a 3D shape by vacuum suction through the through holes while heating the mold, and then cooling. 11. The 3D cover glass of claim 10, comprising removing the 3D cover glass from the 3D cover glass molding die after the cooling, and cutting a skirt portion outside the curved surface portion of the 3D cover glass. manufacturing method. The method for producing a 3D cover glass according to claim 11, comprising polishing the surface of the 3D cover glass after the cutting, and then chemically strengthening the 3D cover glass.

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