CN104291552B - The mould preparing three-dimensional glass and the method using the three-dimensional glass of this mould preparation - Google Patents

The mould preparing three-dimensional glass and the method using the three-dimensional glass of this mould preparation Download PDF

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Publication number
CN104291552B
CN104291552B CN201310304887.9A CN201310304887A CN104291552B CN 104291552 B CN104291552 B CN 104291552B CN 201310304887 A CN201310304887 A CN 201310304887A CN 104291552 B CN104291552 B CN 104291552B
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China
Prior art keywords
glass
mould
die
preparation
dimensional
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CN201310304887.9A
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CN104291552A (en
Inventor
绳炳光
李俊颐
刘书宇
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International Photoelectric Co Ltd Of Zheng Da
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International Photoelectric Co Ltd Of Zheng Da
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    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03BMANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B11/00Pressing molten glass or performed glass reheated to equivalent low viscosity without blowing
    • C03B11/06Construction of plunger or mould
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03BMANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B2215/00Press-moulding glass
    • C03B2215/02Press-mould materials
    • C03B2215/08Coated press-mould dies
    • C03B2215/10Die base materials
    • C03B2215/12Ceramics or cermets, e.g. cemented WC, Al2O3 or TiC
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03BMANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B2215/00Press-moulding glass
    • C03B2215/40Product characteristics
    • C03B2215/41Profiled surfaces

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Re-Forming, After-Treatment, Cutting And Transporting Of Glass Products (AREA)

Abstract

A kind of mould preparing three-dimensional glass.This solid glass includes a curved panel and connects with this curved panel and towards the side arm of direction bending corresponding to the concave surface of this curved panel, and the inside edge of this side arm is positioned on this curved panel relative to the projection of this curved panel.This mould includes die main body and slide block.This die main body includes die and chute, and the definition of this die has the shaping area consistent with this curved panel shape, this chute to should side arm to be arranged at the shaping area of this die peripheral.This slide block is correspondingly arranged with described chute, this slide block includes slider body and the protuberance highlighted from this slider body towards this shaping area, this slider body can make this slide block removably engage along this slide to be arranged on this die, make this protuberance protrude from the interior edge of this shaping area simultaneously.The present invention also provides for a kind of method using the three-dimensional glass of this mould preparation.

Description

The mould preparing three-dimensional glass and the method using the three-dimensional glass of this mould preparation
Technical field
The present invention relates to a kind of mould preparing three-dimensional glass and use this mould preparation solid The method of glass.
Background technology
Its surface of common electronic product is typically provided with a glass shell, to protect interiors of products Display module.At present glass shell major part is all the shape of flat board, and upper at electronic product Seam is understood on surface unavoidably.Another side, the surrounding of electronic product must retain the machine of one fixed width Structure part, in order to hold flat glass, therefore the end face of electronic product cannot be fully utilized. Therefore, three-dimensional or bend glass is applied on the glass shell of electronic product more.And The Major Difficulties of the application and preparation three-dimensional glass in electronic product is, curved when glass sides When bent angle is more than 90 degree, glass product can be wraps closely about centre by mould, cause glass Glass product cannot break away from moulds.
Summary of the invention
In view of the foregoing, it is necessary to a kind of mould preparing three-dimensional glass is provided.This solid glass Glass includes a curved panel and connects with this curved panel and corresponding towards the concave surface of this curved panel The side arm of direction bending, and the inside edge of this side arm is positioned at relative to the projection of this curved panel On this curved panel.This mould includes die main body and slide block.This die main body include die with Chute, the definition of this die has the shaping area consistent with this curved panel shape, and this chute is corresponding The shaping area that this side arm is arranged at this die is peripheral.This slide block is correspondingly arranged with described chute, should Slide block includes slider body and the protuberance highlighted from this slider body towards this shaping area, and this is sliding Block main body can make this slide block removably engage along this slide to be arranged on this die, with Time make this protuberance protrude from the interior edge of this shaping area.
There is a need to provide a kind of method using the three-dimensional glass of above-mentioned mould preparation.The method bag Include:
The material preparing glass is placed in the die of the mould assembled;
Heat described glass material and mould;
After described glass material softens, apply the glass material after external force order softens and tightly attach On mould;
After glass material is attached at described mould, cool down described glass material to form solidification Three-dimensional glass;And
Described each slide block is separated with die main body, to take out described three-dimensional glass.
Compared to prior art, the mould of preparation solid glass provided by the present invention and use The method of the three-dimensional glass of this mould preparation can prepare the angle of bend of side standing more than 90 degree Body glass, and can depart from from mould easily after three-dimensional glass preparation completes.
Accompanying drawing explanation
Fig. 1 is the mould of the three-dimensional glass of the preparation using the specific embodiment of the invention to be provided The schematic diagram of obtained three-dimensional glass.
Fig. 2 is the sectional view of V-V line of cut along Fig. 1.
Fig. 3 is the preparation that provided of the specific embodiment of the invention three-dimensional glass as shown in Figure 1 The three-dimensional exploded view of mould.
Fig. 4 is the assembling figure of mould in Fig. 3.
Fig. 5 is the sectional view of V-V line of cut along Fig. 4.
Fig. 6 is to use mould in Fig. 3 to prepare the flow chart of the method for Fig. 1 neutral body glass.
Main element symbol description
Following detailed description of the invention will further illustrate the present invention in conjunction with above-mentioned accompanying drawing.
Detailed description of the invention
As shown in Figures 1 and 2, the preparation by using the specific embodiment of the invention to be provided is stood The schematic diagram of the three-dimensional glass 3 obtained by the mould 2 of body glass and the section view along V-V direction Figure.This solid glass 3 includes a curved panel 31 and connects and court with this curved panel 31 The side arm 32 of the direction bending that the concave surface of this curved panel 31 is corresponding.Described side arm 32 and institute State curved panel 31 in smoothing junction, and the inward flange of this side arm 32 is relative to described curved panel The projection of 31 is positioned on this curved panel 31.In other words, side arm 32 in this solid glass 3 Relative to the angle of bend of described curved panel 31 more than 90 degree.In the present embodiment, side arm The quantity of 32 is four, and the four side with this curved panel 31 is connected respectively, thus with this arc Panel 31 is collectively forming the three-dimensional glass 3 of a lid.It is understood that when this solid glass Glass 3 is when the protecgulum of an electronic product, it is possible to by overall with side before this electronic product Cladding, and extend to the back side of this electronic product.
Seeing also Fig. 3 to Fig. 5, the preparation provided by the specific embodiment of the invention is such as The three-dimensional exploded view of the mould 2 of the three-dimensional glass 3 shown in Fig. 1, assembling are schemed and along V-V direction Sectional view.This mould 2 includes die main body 21 and slide block 22.In the present embodiment, Described mould 2 includes four slide blocks 22, and the four side of the corresponding described die main body 21 of difference Arrange.When using this mould 2 to prepare three-dimensional glass 3, described four slide blocks 22 are assembled In described die main body 21, and after the three-dimensional glass preparation needing preparation completes, as long as Described four slide blocks 22 are separated from described die main body 21, can will prepare easily Three-dimensional glass take out from this mould 2.
Described die main body 21 includes a substrate 210, chute 212 and die 213.Described Die 213 is arranged on this substrate 210, and its definition has and this curved panel 31 shape phase one The shaping area A of cause, for bearing glass raw material.The corresponding described side arm 32 of described chute 212 It is arranged on the substrate 210 peripheral for shaping area A of this die 213.In the present embodiment, Described die 213 is tied for the cuboid with shaping area A extended from this substrate 210 Structure, described shaping area A is that the upper surface of this die 213 caves in towards this substrate 210 Arc-shaped recess structure.
In the present embodiment, this die main body 21 farther includes the table along described substrate 210 Face extends the projection 211 grown.Chute 212 can be by the gap circle between two adjacent projections 211 Surely form.The thickness of projection 211 is slightly larger than the thickness of this die 213.Specifically, in this reality Executing in mode, described die main body 21 includes four projections 211, described four projections 211 Be respectively arranged at four angles of die main body 21, specifically, each projection 211 away from The both sides of its two neighbouring projections 211 are corresponding with the both sides of described die main body 21.Arbitrarily The region that two adjacent projections 211 are spaced defines chute 212, described chute 212 Width is the distance of said two adjacent projections 211.
Described die 213 include from substrate 210 surface extend grow die side 2131, Die inner bottom 2132 and die cambered surface 2133.Described die side 2131 and each projection 211 Lateral parts lean.Described die side 2131 is not against with described each projection 211 Part is just to corresponding chute 212.Described die cambered surface 2133 is with this die inner bottom 2132 altogether With constituting this shaping area A, wherein, this die cambered surface 2133 and the shape of this die inner bottom 2132 Shape can be according to the shape design for change of the three-dimensional glass of wanted molding.In the present embodiment, institute Stating die inner bottom 2132 is smooth and slightly arc.Described die cambered surface 2133 has smooth Radian, and in smoothing junction with described die inner bottom 2132.
Described slide block 22 is correspondingly arranged with described chute 212, and each slide block 22 can be along this chute 212 slide makes this slide block 22 removably engage to be arranged on this die 213.Described slide block 22 include slider body 221, protuberance 222 and limiting section 223.In the present embodiment, Described in the aspect ratio of described slider body 221, each projection 211 is on described die main body 21 The most slightly higher.
Described protuberance 222 grows towards the extension of this shaping area A from this slider body 221. Making when engaging with this die main body 21 in this slide block 22 slips into this chute 212, this highlights Portion 222 protrudes from the interior edge of this shaping area A.In the present embodiment, described protuberance 222 Including teat top along 2221 with teat inclined-plane 2222.Described teat top is positioned at prominent along 2221 Portion 222 is away from a side of described slider body 221, and described teat top is along the shape of 2221 Shape agrees with mutually with the shape of die 213 upper surface at corresponding shaping area A.Described Teat top along 2221 include connecting with shaping area A lower along 2221b and relatively under this along 2221b More towards shaping area A protruding outside on along 2221a.The upper edge along 2221, the described teat top The position of 2221a slightly highlights the interior edge of corresponding shaping area A, and described teat top is along 2221 Lower agree with mutually along the position of 2221b and the interior edge of corresponding shaping area A.Teat is oblique Face 2222 is the tangent plane that the two ends along described teat top along 2221 extend to both sides, the most adjacent Teat inclined-plane 2222 be mutually butted, and the gap between them is less than 0.2 millimeter.This is dashed forward Going out and form a hierarchic structure between portion 222 and slider body 221, this hierarchic structure is as spacing Portion 223.The ladder knot formed between this limiting section 223 and this die 213 and this chute 212 Structure abuts, thus plays position-limiting action.
The material of described mould 2 selects free hexagonal boron nitride (HBN), silicon oxide (SiO2)、 Aluminium oxide (Al2O3), the porous heatproof that formed of hexagonal crystal system layer carbon (C) and combinations thereof Material, its density is between 1.5g/cm3To 6.5g/cm3Between, pore size is between 0.2 nanometer Between 2 microns, heat-resisting indeformable operating temperature is Celsius between 650 degrees Celsius to 1600 Degree.
As shown in Figure 6, the flow chart of the method for three-dimensional glass is prepared for the above-mentioned mould 2 of use.
Step S201, is placed in the die 213 of the mould 2 assembled by the material preparing glass In.Preferably, this prepares the material of glass selected from passing through chemical mode or thing after shaping Reason mode carries out the glass material of strength of glass enhancing, such as soda-lime glass, aluminosilicate system glass Glass, alkali-free glass, boron glass and combinations thereof thing etc..
Step S202, heats described glass material and mould 2.Specifically, can be by described Sheng The mould 2 having glass material heats as in glass forming furnace, and the temperature of heating is not less than 600 degrees Celsius.
Step S203, after described glass material softens, applies the glass after external force order softens Material is tightly attached on mould 2.Specifically, mould of the present invention 2 is by porous Temperature-resistant material is made, and bleeds substrate 210 from the side, substrate 210 place of mould 2.By It is to be formed by porous temperature-resistant material in described mould 2, from substrate 210 place of mould 2 Bleed and can form vacuum between glass material and mould 2 in side so that the glass after described softening Material is attached on described mould 2 tightly.
Step S204, after glass material is attached at described mould 2, cools down described glass element Material is to form the three-dimensional glass of solidification.
Step S205, is separated described each slide block 22 with die main body 21, to take out State three-dimensional glass.Design by separating type die 2 of the present invention, it is possible to preparation edgewise bend surpasses Cross the three-dimensional glass of 90 degree, and can the most easily solid glass be taken from mould 2 Go out.
The mould of the present invention is not limited only to the manufacture of three-dimensional glass shown in Fig. 1, for forming bending The three-dimensional glass of the angle bending shape more than 90 degree is the most applicable, as long as according to three-dimensional glass Concrete shape change shaping area shape.
Above example is only in order to illustrate technical scheme and unrestricted, although with reference to relatively The present invention has been described in detail by good embodiment, and those of ordinary skill in the art should manage Solve, technical scheme can be modified or equivalent, without deviating from the present invention The spirit and scope of technical scheme.

Claims (14)

1. prepare a mould for three-dimensional glass, this solid glass include a curved panel and with The side arm that this curved panel connects and bends towards the direction that the concave surface of this curved panel is corresponding, and should The inside edge of side arm is positioned on this curved panel relative to the projection of this curved panel, this mould bag Include:
Die main body, including die and chute, the definition of this die has and this curved panel shape phase Consistent shaping area, this chute to should side arm to be arranged at the shaping area of this die peripheral;And
Slide block, this slide block is correspondingly arranged with described chute, and this slide block includes slider body and from being somebody's turn to do The protuberance that slider body is prominent towards this shaping area, this slider body can be along this slide Make this slide block removably engage to be arranged on this die, make this protuberance protrude from this one-tenth simultaneously The interior edge in type district.
2. the mould of the three-dimensional glass of preparation as claimed in claim 1, it is characterised in that: institute Stating die main body and also include that a substrate, described die are arranged on this substrate, described chute is corresponding Described side arm is arranged on the substrate of periphery, shaping area of this die.
3. the mould of the three-dimensional glass of preparation as claimed in claim 2, it is characterised in that: institute Stating die main body also to include extending, along the surface of described substrate, the projection grown, described projection is respectively Being arranged at each angle of described die main body, described chute is by the gap circle between two adjacent projections Surely forming, the thickness of this projection is more than the thickness of this die.
4. the mould of the three-dimensional glass of preparation as claimed in claim 2, it is characterised in that: institute State die to include extending, from substrate surface, die side, die inner bottom and the die arc grown Face, described die side is just to corresponding chute, and described die cambered surface is with described die inner bottom altogether With constituting this shaping area, described die cambered surface has a smooth radian, and with described die inner bottom In smoothing junction.
5. the mould of the three-dimensional glass of preparation as claimed in claim 3, it is characterised in that: institute State the height of slider body more than described projection height on described die main body.
6. the mould of the three-dimensional glass of preparation as claimed in claim 1, it is characterised in that: institute Stating protuberance and include edge, teat top and teat inclined-plane, described teat top is remote along being positioned at described protuberance From a side of described slider body, and the shape on edge, described teat top and corresponding molding The shape of the die upper surface at district is agreed with mutually, and described teat inclined-plane is along edge, described teat top The tangent plane that two ends extend to both sides.
7. the mould of the three-dimensional glass of preparation as claimed in claim 6, it is characterised in that: institute State teat top along include the lower edge connected with shaping area and compared with this lower edge more towards shaping area outside The upper edge that side is prominent, the position on described upper edge slightly highlights the interior edge of corresponding shaping area, institute The interior edge of the position and corresponding shaping area of stating lower edge is agreed with mutually.
8. the mould of the three-dimensional glass of preparation as claimed in claim 6, it is characterised in that: two Two adjacent described teat inclined-planes are mutually butted, and the gap between them is less than 0.2 millimeter.
9. the mould of the three-dimensional glass of preparation as claimed in claim 1, it is characterised in that: institute State slide block and also include that limiting section, described limiting section are shapes between described protuberance and slider body The hierarchic structure become, mutually supports between described limiting section and described die and described chute Lean on.
10. the mould of the three-dimensional glass of preparation as claimed in claim 1, it is characterised in that: institute State mould material select free hexagonal boron nitride, silicon oxide, aluminium oxide, hexagonal crystal system layer carbon and The porous temperature-resistant material that a combination thereof is formed, its density is between 1.5g/cm3To 6.5g/cm3 Between, pore size between 0.2 nanometer to 2 micron, heat-resisting indeformable operating temperature Between 650 degrees Celsius to 1600 degrees Celsius.
11. 1 kinds of mould preparation solids using the three-dimensional glass of preparation as claimed in claim 1 The method of glass, including:
The material preparing glass is placed in the die of the mould assembled;
Heat described glass material and mould;
After described glass material softens, apply the glass material after external force order softens and tightly attach On mould;
After glass material is attached at described mould, cool down described glass material to form solidification Three-dimensional glass;And
Described each slide block is separated with die main body, to take out described three-dimensional glass.
The method of 12. glass of preparation solid as claimed in claim 11, it is characterised in that: The described material of glass of preparing is selected from soda-lime glass, aluminosilicate system glass, alkali-free glass, boron Glass and combinations thereof thing.
13. the method for the three-dimensional glass of preparation as claimed in claim 11, it is characterised in that: When heating glass material, the temperature of heating is not less than 600 degrees Celsius.
The method of 14. glass of preparation solid as claimed in claim 11, it is characterised in that It is real by the following method for apply the glass material after external force order softens tightly being attached on mould Existing: from the side, substrate place of described mould, substrate to be bled, with described glass material with Vacuum is formed so that the glass material after described softening is attached on described mould between mould.
CN201310304887.9A 2013-07-19 2013-07-19 The mould preparing three-dimensional glass and the method using the three-dimensional glass of this mould preparation Active CN104291552B (en)

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Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105563755B (en) * 2015-04-30 2017-11-17 宇龙计算机通信科技(深圳)有限公司 Mould
CN108409115A (en) * 2018-03-15 2018-08-17 广东欧珀移动通信有限公司 Hot pressing die and its preparation method and application for bend glass
CN109133589B (en) * 2018-11-27 2019-03-01 瑞声光学科技(常州)有限公司 Glass baseplate processing mold and glass baseplate processing method
CN111170622B (en) * 2020-01-09 2022-01-07 诚瑞光学(常州)股份有限公司 Glass product forming die, forming equipment and processing method

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4737182A (en) * 1986-12-12 1988-04-12 Ppg Industries, Inc. Glass sheet press support and alignment systems
TW201226343A (en) * 2010-12-22 2012-07-01 Catcher Technology Co Ltd Method for manufacturing three-dimensional glass article
CN102740623A (en) * 2011-04-15 2012-10-17 巍思有限公司 Three-dimensional structure glass and manufacturing method thereof

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3150895B2 (en) * 1996-01-09 2001-03-26 旭テクノグラス株式会社 Glass tray and its mold
JPH10218630A (en) * 1997-02-04 1998-08-18 A F C Ceramic:Kk Mirror finished surface forming mold

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4737182A (en) * 1986-12-12 1988-04-12 Ppg Industries, Inc. Glass sheet press support and alignment systems
TW201226343A (en) * 2010-12-22 2012-07-01 Catcher Technology Co Ltd Method for manufacturing three-dimensional glass article
CN102740623A (en) * 2011-04-15 2012-10-17 巍思有限公司 Three-dimensional structure glass and manufacturing method thereof

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