CN106746526B

CN106746526B - Glass heating graphite mold and manufacturing method thereof

Info

Publication number: CN106746526B
Application number: CN201611129197.4A
Authority: CN
Inventors: 王长明; 唐臻; 谢守德
Original assignee: DONGGUAN HUAQING OPTICAL TECHNOLOGY CO LTD
Current assignee: DONGGUAN HUAQING OPTICAL TECHNOLOGY CO LTD
Priority date: 2016-12-09
Filing date: 2016-12-09
Publication date: 2022-09-30
Anticipated expiration: 2036-12-09
Also published as: CN106746526A

Abstract

A graphite mould for heating glass is composed of a front mould consisting of front base and front mould core made of graphite material, a back mould consisting of back base and back mould core made of graphite material, a cavity matched with said front mould core and arranged in said cavity of front base, a cavity matched with the rear mould core is arranged on the rear mould base, the rear mould core is arranged in the cavity of the rear mould base, the middle area of the opposite surfaces of the front mold core and the rear mold core is a 3D curved surface suitable for processing hot bent glass during mold closing, a plurality of supporting insert through holes are respectively arranged on the edge areas of the opposite surfaces of the front mold core and the rear mold core, supporting inserts are arranged in the supporting insert through holes, when the die is closed, the supporting inserts oppositely arranged on the front die core and the rear die core are contacted, so that the positioning and supporting functions of the die cores are achieved, and the pressure of the die cores is borne. The invention improves the molding quality of the graphite mold and is easy for large-scale mass production.

Description

Glass heating graphite mold and manufacturing method thereof

Technical Field

The invention relates to a glass heating graphite mold and a manufacturing method thereof.

Background

Along with the product demands of frivolousization, fashion and practicality of 3C electronic products such as cell-phones, wearable products, mobile electronics, the more and more glass material that uses of current electronic product shell to the cell-phones, wearable products, the more and more use gradual change of product appearance such as mobile electronics, 3D curved surface glass screen or backplate of complicated appearance such as cambered surface, 3D dysmorphism curved surface.

The 2D cambered surface or 3D cambered surface glass used by the 3C mobile electronic equipment is generally realized by adopting a process technology of hot bending after high-temperature heating of glass, and is widely applied to the production of various 3C electronic product cambered surface screens. Meanwhile, the graphite material has the advantages of excellent high heat conduction, high temperature resistance, low linear expansion coefficient, good thermal stability, good heating impact resistance and good chemical stability, is not easy to be infiltrated by molten glass, does not change the components of the glass, and is an ideal material for a glass high-temperature hot bending die.

But because graphite is easily oxidized on the surface of the graphite mold in the process of producing the curved glass by high-temperature heating, carbon dioxide and carbon monoxide are generated, so that the size of the mold is slowly reduced in the continuous use process, and the generated curved glass has poor size, damages the surface of the curved glass and damages the mold.

Because glass hot bending belongs to the secondary processing to plane glass, the forming technology of glass high temperature hot bending and the controllability and the precision of a hot bending mould are limited, so that the precision of 3D curved surface glass is lower, the integral forming requirement in a plastic mould required by a 3C electronic product cannot be met, and meanwhile, only one mould and one hole can be achieved due to the precision problem, the forming period is long, and the productivity is low and the cost is high.

And because the properties such as the stretching, bending resistance, elasticity and the like of the graphite material are far lower than those of metal steel, the graphite mold is easier to damage and difficult to maintain compared with the mold made of conventional metal materials, the service life is short, and the production cost is high.

Disclosure of Invention

The invention mainly aims to overcome the defects of the prior art and provides a glass heating graphite mold and a manufacturing method thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

a glass heating graphite die comprises a front die and a rear die, wherein the front die comprises a front die base and a front die core made of a graphite material, the rear die comprises a rear die base and a rear die core made of a graphite material, a cavity matched with the front die core is formed in the front die base, the front die core is installed in the cavity of the front die base, a cavity matched with the rear die core is formed in the rear die base, the rear die core is installed in the cavity of the rear die base, the middle area of the opposite surfaces of the front die core and the rear die core is a 3D curved surface suitable for processing hot-bending glass during die assembly, a plurality of supporting insert through holes are respectively formed in the edge areas of the opposite surfaces of the front die core and the rear die core, supporting inserts are installed in the supporting insert through holes, and are contacted by the supporting inserts oppositely arranged on the front die core and the rear die core during die assembly, the positioning and supporting function of the die core is achieved and the pressure of the die core is born.

Further:

each supporting insert is independently adjustable in thickness so as to adjust die assembly precision and pressure balance of the die core.

The front mold base/the rear mold base are provided with guide pillar mounting holes, guide pillars are mounted in the guide pillar mounting holes, positioning holes are formed in the rear mold base/the front mold base corresponding to the guide pillar mounting holes, and the guide pillars are inserted into the corresponding positioning holes when the mold is closed.

And a guide sleeve for preventing abrasion is arranged in the positioning hole.

The surfaces of the front mold core and the rear mold core are provided with anti-oxidation layers.

The anti-oxidation layer is a silicon carbide or tungsten carbide or silicon dioxide or aluminum oxide or titanium dioxide film.

The front die base is provided with a plurality of cavities for mounting a plurality of front die cores, and the front die base is provided with a plurality of cavities with the same number for mounting a plurality of rear die cores.

The front die base and the rear die base are made of die steel or graphite materials, and the support insert is made of die steel.

A manufacturing method for manufacturing the glass heating graphite mold comprises the following steps:

manufacturing a front mold base, a rear mold base, a front mold core made of a graphite material and a rear mold core made of a graphite material, wherein a cavity matched with the front mold core is formed in the front mold base, a cavity matched with the rear mold core is formed in the rear mold base, a 3D curved surface suitable for processing hot bent glass during mold closing is formed in the middle area of the opposite surface of the front mold core and the rear mold core, and a plurality of supporting insert through holes are respectively formed in the edge areas of the opposite surface of the front mold core and the rear mold core; manufacturing a support insert, and installing the support insert into the support insert through hole, so that the support insert oppositely arranged on the front mold core and the rear mold core is contacted with each other when the mold is closed, thereby playing a role in positioning and supporting the mold cores and bearing the pressure of the mold cores; and installing the front mold core into a cavity of the front mold base, and installing the rear mold core into a cavity of the rear mold base.

Further, carrying out anti-oxidation coating process treatment on the front mold core and the rear mold core; preferably, the mold core is treated under high temperature by using a PVD vacuum coating process to form a uniform silicon carbide or tungsten carbide or silicon dioxide or aluminum oxide film on the surface of the mold core, or a vacuum pressure dipping or spraying method is used to uniformly attach a layer of titanium dioxide or aluminum oxide film or tungsten carbide film on the surface of the mold core and the mold core is cured at high temperature.

The embodiment of the invention has the following beneficial effects:

1. the multi-hole antioxidant glass heating graphite mold is realized, and large-scale production is easy while the molding quality of the graphite mold is improved.

2. The anti-oxidation coating is simple in process and wide in applicability to the graphite mold, the problems that the forming size of the 3C electronic product heating graphite mold is changed due to high temperature and the mold is damaged are solved, the forming quality is improved, meanwhile, the service life of the mold is greatly prolonged, and the production and manufacturing cost of 3D curved glass is reduced.

3. The isolation type mold structure design avoids direct contact between the front mold core and the rear mold core of the graphite mold and hard objects such as metal and the like, prolongs the service life of the mold and improves the stability of the mold, also improves the mold closing precision, ensures the stability and consistency of stress when glass is bent, and improves the molding precision of the glass heating graphite mold.

4. The multi-cavity graphite mold and the adjustable support column structure which are combined by the frame are adopted, so that the problem that the mold is easy to damage when the stability of the glass heating graphite mold is greatly improved because the graphite mold is too big and the pressure is unbalanced is solved, and the support insert is used for replacing the graphite mold body with the pressure.

5. Unique non-contact and the mould structure of cooperation anti-oxidation coating make graphite material only contact with glass, have avoided graphite material surface coating and non-glass contact, avoid the coating damage problem because of wearing and tearing or collision lead to, the effectual anti-oxidation coating who protects graphite mould top layer has promoted coating and graphite mould's life.

6. The graphite oxidation-resistant coating can effectively fill pores on the surface of the graphite material, has excellent oxidation resistance, wear resistance, corrosion resistance and impact resistance, effectively solves the problem of high-temperature oxidation of the graphite mold, and makes up the defects of the performance of the graphite material in a high-temperature hot-bending glass mold.

7. The die parts all use the assembled die structure, and metal thermal expansion allowance is reserved, so that mutual friction between graphite materials and the die parts is avoided, the easily worn and damaged parts of the graphite die can be replaced by standard parts, the graphite die is simple and convenient to maintain, and the maintenance cost is low.

8. The supporting insert on each graphite mold core adjusts the pressed amount and the pressure balance of the single-cavity graphite mold core, the glass hot bending precision is accurately controlled, and the stability and the forming precision of the glass hot bending process are greatly improved.

9. Through mutual adjustment of the multi-cavity supporting inserts, the pressure balance of the whole set of multi-cavity graphite mold is comprehensively adjusted, the problems of poor controllability and low forming precision of a hot bending process are solved while the hot bending precision of the glass is accurately controlled, the problem that the size of the multi-cavity hot bending mold is difficult to control is solved, and efficient production of the glass heating graphite process is realized.

Drawings

FIG. 1 is a schematic illustration of graphite material preparation according to an embodiment of the present invention;

FIG. 2 is a schematic view of a mold core supporting insert according to an embodiment of the present invention;

FIGS. 3a and 3b are schematic views of a back mold base and a front mold base, respectively, of a mold according to an embodiment of the invention;

fig. 4a and 4b are schematic views of a front mold base and a rear mold base respectively provided with a multi-cavity mold insert, a processing guide pillar and a supporting insert hole according to an embodiment of the present invention;

FIGS. 5a and 5b are views of a finished rear mold core and a front mold core, respectively, according to an embodiment of the present invention;

FIGS. 6a and 6b are assembled rear and front molds, respectively, of an embodiment of the present invention;

FIG. 7 is a schematic view of the overall structure of the mold according to the embodiment of the present invention;

FIG. 8 is a schematic view of a hot bent glass product made in accordance with an embodiment of the present invention.

Detailed Description

The embodiments of the present invention will be described in detail below. It should be emphasized that the following description is merely exemplary in nature and is in no way intended to limit the scope of the invention or its applications.

Referring to fig. 1 to 8, in an embodiment, a glass heating graphite mold includes a front mold and a rear mold, the front mold includes a front mold base 1 and a front mold core 3 made of a graphite material, the rear mold includes a rear mold base 2 and a rear mold core 4 made of a graphite material, a cavity 5 fitted to the front mold core is formed in the front mold base, the front mold core is installed in the cavity of the front mold base, a cavity fitted to the rear mold core is formed in the rear mold base, the rear mold core is installed in the cavity of the rear mold base, a middle area of opposite surfaces of the front mold core and the rear mold core is a 3D curved surface suitable for processing hot bent glass 11 during mold closing, a plurality of support inserts 6 are respectively formed in edge areas of the opposite surfaces of the front mold core and the rear mold core, and support inserts 7 are installed in the support inserts, when the die is closed, the front die core and the rear die core are contacted by the supporting inserts which are oppositely arranged, so that the positioning and supporting functions of the die core are achieved, and the pressure of the die core is born.

In a preferred embodiment, each support insert is configured to be capable of being adjusted in thickness individually to adjust the clamping accuracy and the pressure balance of the mold core.

In a preferred embodiment, the front mold base/the rear mold base is provided with guide post mounting holes 8, guide posts 9 are mounted in the guide post mounting holes, the rear mold base/the front mold base is provided with positioning holes 10 corresponding to the guide post mounting holes, and the guide posts are inserted into the corresponding positioning holes when the mold is closed.

In a more preferred embodiment, a guide sleeve for preventing abrasion is arranged in the positioning hole.

In a preferred embodiment, the front mold core and the rear mold core have an anti-oxidation layer on their surfaces. The anti-oxidation layer can be a silicon carbide or tungsten carbide or silicon dioxide or aluminum oxide or titanium dioxide film layer.

In a preferred embodiment, the front mold base has a plurality of cavities for receiving the plurality of front mold inserts, and the front mold base has a plurality of cavities for receiving the plurality of rear mold inserts.

In a preferred embodiment, the front mold base and the rear mold base are made of a mold steel material or a graphite material, and the support insert is made of a mold steel material.

Referring to fig. 1 to 8, in another embodiment, a method for manufacturing the glass-heated graphite mold includes:

manufacturing a front mold base 1, a rear mold base 2, a front mold core 3 made of graphite materials and a rear mold core 4 made of graphite materials, wherein a cavity 5 matched with the front mold core is formed in the front mold base, a cavity matched with the rear mold core is formed in the rear mold base, a 3D curved surface suitable for processing hot bent glass 11 during mold closing is formed in the middle area of the opposite surface of the front mold core and the rear mold core, and a plurality of supporting insert through holes 6 are respectively formed in the edge area of the opposite surface of the front mold core and the rear mold core; manufacturing a support insert 7, and installing the support insert into the support insert through hole, so that the support inserts oppositely arranged on the front mold core and the rear mold core are contacted when the mold is closed, thereby playing the roles of positioning and supporting the mold cores and bearing the pressure of the mold cores; and installing the front mold core into the cavity of the front mold base, and installing the rear mold core into the cavity of the rear mold base to complete the assembly of the base and the mold core.

Features and advantages of particular embodiments of methods of making glass-heated graphite molds are further described below in conjunction with fig. 1-7.

1. The surface of the high purity graphite material is pre-machined by mechanical cutting as shown in figure 1.

The cutting process makes 4 side surfaces of the periphery of the graphite material rectangular in parallel or perpendicular to each other as a reference surface for post-processing. The upper and lower surfaces are also machined, the flatness is within 0.05mm, and the surfaces are perpendicular to the side surfaces. The roughness of the side surface is as low as possible to 3.2 to improve the precision of the post-processing.

2. The supporting insert on the graphite mold core is processed and manufactured into a standard part which is used as a mold part subsequently installed on the graphite mold core and bears the pressure and the limiting function when the mold is closed, as shown in fig. 2.

The supporting insert is made of high-temperature-resistant die steel, and the die assembly precision of the graphite die and the compression balance of the graphite die core can be adjusted by installing the supporting insert. The supporting insert can be made into a standard part shared by a plurality of sets of dies, the size of the supporting insert can be divided into a range of 0.005 mm-0.50 mm, and a plurality of sets of supporting inserts are sequentially made according to a height difference value of 0.01 mm. The supporting insert has enough area and strength to bear the pressure of the mold, and is determined according to the specific product requirements and the mold structure, and the form is not limited.

3. And (3) manufacturing bases of front and rear mold cores of the graphite mold by using mold steel or graphite materials, and finishing the assembly dimension, as shown in fig. 3a and 3 b.

Because the 3D hot bending glass has a longer forming period, in the actual production, the graphite mold base is used, and the graphite mold is installed into the graphite mold base in an embedding mode according to the effective working plane of the hot bending machine and the size of a product, so that the graphite mold with one mold and multiple cavities is manufactured. The graphite mold base and the graphite insert are combined, so that the processing difficulty caused by the overlarge graphite mold can be reduced, and the processing and manufacturing difficulty of the graphite mold is reduced; the size difference of the hot bending die among multiple holes caused by the fact that the die is too large and the pressure is unbalanced is improved, the die manufacturing precision is improved, the problem that the die is damaged is avoided, the forming efficiency is greatly improved, and the production and manufacturing cost of the 3D hot bending surface glass is reduced.

4. And (3) processing a guide post hole of the mold base and a support insert through hole of the graphite mold core, and completing the assembly of the graphite front and rear mold cores and the mold base, as shown in fig. 4a and 4 b.

The thicknesses of the anti-oxidation coatings and the allowance of the metal thermal expansion coefficient are reserved in the guide pillar mounting hole, the positioning hole and the insert hole. The guide post holes of the front and rear mold cores are processed together to improve the guiding and positioning precision of the graphite mold.

5. The graphite material is machined by cutting and finishing to form the 3D curved surface features of the hot bent glass and the parting plane of the mold, as shown in fig. 5a and 5 b.

Because the toughness of the graphite material is not as good as that of the die steel, the die parting surface is in large-area smooth transition in order to improve the stability of the hot bending die. And reserving the thickness allowance of the subsequent die-saving polishing and oxidation-resistant coating for the characteristic size of the hot bending area on the die.

The assembled multi-cavity glass hot pressing rear mold and front mold are shown in fig. 6a and 6 b.

6. And (3) carrying out mold-saving polishing on the hot bending surface part of the graphite mold, grinding the hot bending surface part to be more than #800 sand paper, removing cutting lines on the surface of the graphite mold, and enabling the surface of the graphite mold to be smooth and consistent.

7. And carrying out anti-oxidation coating process treatment on the front and rear mold cores of the mold to isolate the graphite material from directly contacting with air.

According to the first scheme, a PVD vacuum coating process is used, a graphite mold core is treated under a high-temperature condition, special gas is used for releasing silicon and carbon, the silicon and the carbon are combined, a graphite mold is wrapped, a SiC protective layer is formed, formed SiC is firmly adhered to the graphite mold, an even silicon carbide film layer is formed on the surface of the graphite mold, air holes in the surface of a graphite material are sealed, the graphite mold is isolated from air, and the effects of oxidation resistance, wear resistance, corrosion resistance and impact resistance on the graphite material are achieved. In addition to forming a silicon carbide film, such processes may also be used to form a tungsten carbide or silicon dioxide or aluminum oxide film.

And according to the second scheme, a vacuum pressurization dipping or spraying method is used, so that a titanium dioxide or aluminum oxide film layer or a tungsten carbide film layer is uniformly attached to the surface of the graphite mold, high-temperature curing is carried out, air holes in the surface of the graphite material are sealed and isolated from air, and the effects of oxidation resistance, wear resistance, corrosion resistance and impact resistance on the graphite material are achieved.

8. The mold is subjected to size detection and correction processing to complete the adaptation (mold matching) of the whole set of graphite mold, as shown in fig. 6a and 6b, thereby realizing the whole set of one-mold multi-cavity glass heating graphite mold, as shown in fig. 7.

The guide sleeve is arranged on the guide pillar positioning side of the graphite mold, so that the guide pillar is prevented from being in direct contact with the graphite mold for a long time, and the abrasion of the abrasion-resistant coating or the reduction of the positioning precision of the mold are prevented.

The supporting inserts on the front and rear mould cores play a role in supporting the front and rear moulds of the mould, and are contacted and positioned by the supporting inserts of the front and rear mould cores when the mould is closed, so that the coating is prevented from being damaged by the long-term direct contact of the front and rear mould cores of the graphite mould, and the mould closing precision is improved. Each support insert can all adjust thickness alone, makes graphite mold pressure balance when protecting graphite mold, and is especially to the curved graphite mold of many caves heat, and the effect is obvious. And steel thermal expansion allowance is reserved in the supporting insert hole and the guide pillar hole, so that the reduction of the mold precision or the damage to a graphite mold is avoided.

According to the product structure and the hot bending process requirements, a plurality of groups of graphite molds with the radian of the curved surface sequentially from small to large can be manufactured, and the planar glass is gradually hot bent into the required product structure according to the product size requirements, so that the size precision of the hot bent surface glass is ensured.

During working, the graphite mold is arranged on the curved glass hot bending machine and adjusted through the supporting insert, so that high-precision forming of the multi-cavity glass graphite mold is realized.

Specifically, a plurality of groups of glass heating graphite molds are sequentially arranged on a continuous hot bending furnace on a curved glass hot bending machine according to the process requirements, and the heating temperature of the graphite molds is set, generally within the range of 400-700 ℃. The pressed capacity and the pressure balance of the single-hole graphite mold core are adjusted through the height dimension of the supporting insert on each graphite mold core, so that the glass hot bending precision can be accurately controlled. Meanwhile, the pressure balance of the whole set of multi-cavity graphite mould is adjusted through mutual adjustment of the multi-cavity support inserts, so that the problems of poor controllability and low forming precision of a hot bending process are solved. And performing hot bending processing one by one to realize one-die multi-cavity high-precision molding of the glass heating graphite die, and finally cooling to form 3D curved glass with required size of the product, as shown in figure 8.

The foregoing is a more detailed description of the invention in connection with specific/preferred embodiments and is not intended to limit the practice of the invention to those descriptions. It will be apparent to those skilled in the art that various substitutions and modifications can be made to the described embodiments without departing from the spirit of the invention, and these substitutions and modifications should be considered to fall within the scope of the invention.

Claims

1. A glass heating graphite mold comprises a front mold and a rear mold, and is characterized in that the front mold comprises a front mold base and a front mold core made of a graphite material, the rear mold comprises a rear mold base and a rear mold core made of a graphite material, a cavity matched with the front mold core is formed in the front mold base, the front mold core is installed in the cavity of the front mold base, a cavity matched with the rear mold core is formed in the rear mold base, the rear mold core is installed in the cavity of the rear mold base, the middle area of the opposite surfaces of the front mold core and the rear mold core is a 3D curved surface suitable for processing hot bent glass during mold closing, a plurality of insert supporting through holes are respectively formed in the edge areas of the opposite surfaces of the front mold core and the rear mold core, supporting inserts are installed in the supporting insert through holes, and are contacted with the supporting inserts oppositely arranged on the front mold core and the rear mold core during mold closing, the mould core positioning and supporting function is achieved, the pressure of the mould core is borne, and each supporting insert is independently adjusted in thickness so as to adjust the mould closing precision and the pressure balance of the mould core.

2. The glass-heated graphite mold of claim 1, wherein the front mold base/the rear mold base is provided with guide post mounting holes, guide posts are mounted in the guide post mounting holes, positioning holes are formed in the rear mold base/the front mold base corresponding to the guide post mounting holes, and the guide posts are inserted into the corresponding positioning holes when the mold is closed.

3. The glass-heated graphite mold of claim 2, wherein a guide bushing for preventing abrasion is provided in the positioning hole.

4. The glass-heated graphite mold of any of claims 1 to 3, wherein the front mold core and the rear mold core have an oxidation resistant layer on their surfaces.

5. The glass-heated graphite mold of claim 4, wherein the oxidation resistant layer is a silicon carbide or tungsten carbide or silicon dioxide or aluminum oxide or titanium dioxide film.

6. The glass-heated graphite mold of any one of claims 1 to 3, wherein the front mold base has a plurality of cavities for receiving a plurality of the front mold inserts, and the front mold base has a plurality of cavities for receiving a plurality of the rear mold inserts.

7. The glass-heated graphite mold of any of claims 1 to 3, wherein the material of the front mold base and the rear mold base is a mold steel or graphite material, and the material of the support insert is a mold steel.

8. A method of making the glass-heated graphite mold of any of claims 1 to 7, comprising:

9. The method of claim 8, wherein the front mold insert and the rear mold insert are treated with an oxidation-resistant coating.

10. The method of claim 8, wherein the core is treated by PVD vacuum coating process at high temperature to form a uniform layer of silicon carbide, tungsten carbide, silicon dioxide, or aluminum oxide, or vacuum pressure dipping or spraying is used to uniformly adhere a layer of titanium dioxide, aluminum oxide, or tungsten carbide on the surface of the core, and the coating is cured at high temperature.