Curved glass forming method and pressing die

Abstract

The invention discloses a curved glass forming method and a pressing die. The method comprises the following steps: placing glass to be formed on a concave die; the middle male die is matched with the female die to press the middle area of the to-be-formed glass; after the middle area is pressed and formed by the middle male die, the pressing state of the middle male die is kept, meanwhile, the edge male die is matched with the female die to press the edge area of the to-be-formed glass, and the edge area is heated. According to the invention, by adjusting the sequence of step-by-step compression molding, the middle area is firstly compressed, so that the wrinkle degree of the peripheral area of the middle area can be improved, the edge area of the to-be-molded glass can be expanded and dispersed, the influence of wrinkles is greatly weakened, and then the edge area is compressed and heated; according to the invention, the edge region shows higher molecular thermal motion under the dual action of pressure and temperature, and wrinkles diffused to the edge region become smooth under the motion trend, so that the problem of poor optics caused by the wrinkles can be eliminated.

Description

Technical Field

[0001] The invention relates to the technical field of glass manufacturing, and in particular to a curved glass forming method and a pressing mold. Background Art

[0002] The production and preparation of curved glass generally uses a forming mold to apply pressure to the preheated glass so that it fits the mold and is formed.

[0003] The traditional pressing method is one-step pressing, that is, using an integrated punch to press the entire flat glass. In this process, the pressing surface of the punch does not press the surface of the glass plate at the same time, but the middle area of ​​the punch contacts the middle area of ​​the flat glass first and then presses, and then gradually expands the pressing range to the surrounding until the periphery of the punch contacts the glass sheet for pressing. However, this molding method easily causes wrinkles on the edges, especially as the area, curvature, and arch height of the curved glass increase, the wrinkles on the edges become more obvious.

[0004] In the prior art, a distributed pressing molding process is often used, that is, a split punch is used to first press the edge of the glass plate through the edge punch, and then the middle area of ​​the glass plate is pressed through the middle punch. However, this process only shrinks the original wrinkle area around the glass plate to the area corresponding to the position around the inner mold, and thus still cannot eliminate the optical problems caused by the wrinkles. Summary of the invention

[0005] The purpose of the present invention is to provide a curved glass forming method and a pressing mold to solve the technical problem that the current curved glass forming method and pressing mold cannot eliminate the optical defects caused by wrinkles.

[0006] The above-mentioned purpose of the present invention can be achieved by adopting the following technical solutions:

[0007] The present invention provides a curved glass forming method, comprising the following steps: placing a glass to be formed on a concave mold; a middle convex mold cooperates with the concave mold to press the middle area of ​​the glass to be formed; after the middle convex mold presses the middle area into shape, the pressing state of the middle convex mold is maintained, and at the same time, a side convex mold cooperates with the concave mold to press the side area of ​​the glass to be formed, and the side area is heated.

[0008] In an embodiment of the present invention, before placing the glass to be formed on the concave mold, the curved glass forming method further comprises: preheating the glass to be formed to 500° C. to 750° C.

[0009] In an embodiment of the present invention, during the process of the middle punch pressing the middle area, the time required for the middle punch to descend from its lowest point contacting the glass to be formed to the outer edge of the middle punch contacting the glass to be formed is less than or equal to 0.1s.

[0010] In an embodiment of the present invention, before the middle punch presses the middle region, the middle punch is lifted and positioned to its initial pressing position before pressing, and the side punch is also lifted and positioned to its position to be pressed, wherein:

[0011] The position to be pressed of the edge punch is higher than the initial pressing position of the middle punch, and the height difference h is 1 mm to 10 mm.

[0012] In an embodiment of the present invention, during the process of the edge punch pressing the edge region, it also includes: heating the surrounding area of ​​the middle region.

[0013] In an embodiment of the present invention, there is a pressing gap between the inner edge of the side punch and the outer edge of the middle punch, and the glass to be formed has a buffer area corresponding to the pressing gap between the side area and the middle area; in the process of the side punch pressing the side area, it also includes: heating the buffer area.

[0014] In an embodiment of the present invention, the heating temperature is 550°C to 700°C.

[0015] In an embodiment of the present invention, the middle punch is provided with a middle adsorption structure, which is connected to the middle vacuum structure; the side punch is provided with a side adsorption structure, which is connected to the side vacuum structure; after the side punch presses the side area into shape, the curved glass forming method further includes the following steps: the side vacuum structure vacuums the side adsorption structure so that the side adsorption structure adsorbs the side area to the side punch; the vacuum state of the side adsorption structure is maintained, while the middle vacuum structure vacuums the middle adsorption structure so that the middle adsorption structure adsorbs the middle area to the middle punch, and the vacuum degree of the middle adsorption structure is controlled to be lower than the vacuum degree of the side adsorption structure.

[0016] The present invention provides a pressing mold, comprising: a concave mold for placing glass to be formed; a middle convex mold, which can be raised and lowered above the concave mold; and a side convex mold, which can be raised and lowered above the concave mold and is located around the middle convex mold; wherein the pressing mold can successively form an inner mold pressing state and an outer mold pressing state; in the inner mold pressing state, there is a gap between the side convex mold and the glass to be formed, and the middle convex mold cooperates with the concave mold to press the middle area of ​​the glass to be formed; in the outer mold pressing state, the middle convex mold maintains a pressing state, and the side convex mold cooperates with the concave mold to press the side area of ​​the glass to be formed; wherein the pressing mold is also provided with a heating structure, and the heating structure can be heated in the outer mold pressing state, and the heating area of ​​the heating structure can cover the side area.

[0017] In an embodiment of the present invention, the heating structure is disposed on the concave mold.

[0018] In an embodiment of the present invention, the concave mold is annular, and the inner edge of the concave mold is located inside the outer edge of the middle convex mold; the heating area of ​​the heating structure includes the area between the inner edge of the concave mold and the edge of the glass to be formed.

[0019] In an embodiment of the present invention, the distance between the inner edge of the concave mold and the edge of the glass to be formed is 15 mm to 25 mm.

[0020] In an embodiment of the present invention, the female mold can be raised and lowered, and the pressing mold further comprises a molding positioning ring, which can be raised and lowered and is located at the inner side of the female mold.

[0021] In an embodiment of the present invention, a pressing gap is provided between the inner edge of the side punch and the outer edge of the middle punch, and the glass to be formed has a buffer area corresponding to the pressing gap between the side area and the middle area.

[0022] In an embodiment of the present invention, the width of the pressing gap is less than 10 mm.

[0023] In an embodiment of the present invention, the edge of the glass to be formed is located inside the outer edge of the edge convex mold, and the distance between the edge of the glass to be formed and the outer edge of the edge convex mold is 5 mm to 40 mm.

[0024] In an embodiment of the present invention, the outer edge of the middle convex mold is located inside the edge of the glass to be formed, and the distance between the outer edge of the middle convex mold and the edge of the glass to be formed is 10 mm to 40 mm.

[0025] In an embodiment of the present invention, the middle convex mold is provided with a middle adsorption structure, and the middle adsorption structure is connected to the middle vacuum pumping structure; the side convex mold is provided with a side adsorption structure, and the side adsorption structure is connected to the side vacuum pumping structure;

[0026] The pressing mold can successively form a first adsorption state and a second adsorption state; in the first adsorption state, the edge adsorption structure is vacuumed by the edge vacuum structure so that the edge area and the edge punch are adsorbed and fitted; in the second adsorption state, the edge adsorption structure maintains a vacuum state, and the middle adsorption structure is vacuumed by the middle vacuum structure so that the middle area and the middle punch are adsorbed and fitted, and the vacuum degree of the middle adsorption structure is lower than the vacuum degree of the edge adsorption structure.

[0027] The characteristics and advantages of the present invention are:

[0028] The curved glass forming method and pressing mold of the present invention first presses the middle area of ​​the glass to be formed by cooperating with the concave mold through the middle convex mold. Since the size of the middle area is smaller than the overall size of the glass to be formed, the wrinkle degree of the peripheral area of ​​the middle area can be improved and can be expanded and dispersed to the edge area of ​​the glass to be formed, which greatly reduces the influence of the wrinkles; then the edge area of ​​the glass to be formed is pressed and formed by cooperating with the concave mold through the edge convex mold and the pressing state of the middle convex mold is maintained. At the same time, the edge area is heated so that the edge area shows higher molecular thermal motion under the dual effects of pressure and temperature, and the wrinkles diffused to the edge area become smooth under this motion trend. Therefore, the present invention can eliminate the optical defects caused by wrinkles by adjusting the order of step-by-step pressing and forming, first pressing the middle area, then pressing the edge area and heating the edge area. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 This is a state diagram of the glass to be formed being positioned and transported to the forming area of ​​the present invention.

[0031] Figure 2 This is a diagram of height adjustment of the side punch and the middle punch of the present invention before pressing.

[0032] Figure 3 This is a diagram showing the initial state of the middle punch pressing of the present invention.

[0033] Figure 4 The figure is a dimensional relationship diagram among the edge convex mold, the middle convex mold, the concave mold, the molding positioning ring and the glass to be molded of the present invention.

[0034] Figure 5 This is a diagram showing the completed state of the middle punch pressing of the present invention.

[0035] Figure 6 This is a diagram showing the completed state of the edge punch pressing of the present invention.

[0036] Figure 7 This is a state diagram of the side convex mold and the middle convex mold of the present invention adsorbing the glass to be formed.

[0037] In the figure:

[0038] 1. Concave mold; 11. Inner edge; 12. Outer edge; 13. Concave mold lifting member; 2. Central punch; 21. Outer edge; 22. Central lifting member; 23. Central vacuum chamber; 3. Side punch; 31. Inner edge; 32. Outer edge; 33. Side lifting member; 34. Side vacuum chamber; 4. Molding positioning ring; 41. Outer edge; 42. Positioning lifting member; 5. Glass to be molded; 51. Central area; 511. Peripheral area; 52. Side area; 53. Buffer area; 54. Edge; 6. Furnace top; 7. Furnace bottom. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Implementation Method 1

[0041] The present invention provides a method for forming curved glass, comprising the following steps: Figure 3 As shown, the glass 5 to be formed is placed on the concave mold 1; Figure 5 As shown, the middle convex mold 2 cooperates with the concave mold 1 to press the middle area 51 of the glass 5 to be formed; Figure 6 As shown, after the middle punch 2 presses the middle area 51 into shape, the pressing state of the middle punch 2 is maintained, and at the same time, the side punch 3 cooperates with the die 1 to press the side area 52 of the glass 5 to be formed, and the side area 52 is heated.

[0042] The curved glass forming method of the present invention first presses the middle area 51 of the glass 5 to be formed by the middle convex mold 2 in cooperation with the concave mold 1. Since the size of the middle area 51 is smaller than the overall size of the glass 5 to be formed, the wrinkle degree of the peripheral area 511 of the middle area 51 can be improved and can be extended and dispersed to the edge area 52 of the glass 5 to be formed, greatly reducing the influence of the wrinkles; then the edge area 52 of the glass 5 to be formed is pressed and formed by the edge convex mold 3 in cooperation with the concave mold 1 and the pressing state of the middle convex mold 2 is maintained. At the same time, the edge area 52 is heated, so that the edge area 52 exhibits higher molecular thermal motion under the dual effects of pressure and temperature, and the wrinkles diffused to the edge area 52 become smooth under this motion trend. Therefore, the present invention can eliminate the optical defects caused by wrinkles by adjusting the order of step-by-step pressing and forming, first pressing the middle area 51, then pressing the edge area 52 and heating the edge area 52.

[0043] Specific, combined Figure 4 , Figure 5 as well as Figure 6 As shown, the middle convex mold 2 is arranged above the concave mold 1 in a manner that it can be raised and lowered. The outer edge 21 of the middle convex mold 2 is located inside the edge 54 of the glass 5 to be formed, and the distance a between the outer edge 21 of the middle convex mold 2 and the edge 54 of the glass 5 to be formed is 10 mm to 40 mm, that is, the outer edge of the middle region 51 of the glass 5 to be formed is 10 mm to 40 mm away from the edge of the glass 5 to be formed, preferably 15 to 25 mm. Figure 3 , Figure 4 as well as Figure 5 As shown, the edge punch 3 is arranged above the die 1 and around the middle punch 2 in a manner that it can be raised and lowered, that is, the edge punch 3 is annular, and the middle punch 2 is located inside the edge punch 3. To ensure that the edge punch 3 can completely cover the edge area 52 of the glass 5 to be formed for pressing after it is lowered, the edge 54 of the glass 5 to be formed is located inside the outer edge 32 of the edge punch 3, and the distance b between the edge 54 of the glass 5 to be formed and the outer edge 32 of the edge punch 3 is 5 mm to 40 mm, preferably 10 mm to 20 mm.

[0044] like Figure 3As shown, the glass to be formed 5 is generally a flat glass. Before placing the glass to be formed 5 on the concave mold 1, the curved glass forming method includes: preheating the glass to be formed 5 to soften the glass to be formed 5, so as to facilitate the glass to be formed 5 to be pressed and formed. The concave mold 1, the middle punch 2 and the side punch 3 are all installed in the forming area of ​​a heating furnace. The heating furnace can also be provided with a conveying mechanism, and the glass to be formed 5 is conveyed to the forming area by the conveying mechanism. In addition, the heating furnace is provided with a heating area, a forming area, an annealing area and a cooling area in sequence along the conveying direction of the conveying mechanism. The conveying mechanism first conveys the glass to be formed 5 to the heating area for preheating, then conveys it to the forming area for pressing, and after pressing and forming, conveys it to the annealing area for annealing, and then conveys it to the cooling area for cooling after annealing, and takes it out of the furnace after cooling.

[0045] In this embodiment, the temperature of the heating zone is 500°C to 750°C, preferably 500°C to 650°C. The conveying speed of the conveying mechanism in the heating zone is 50mm / s to 450mm / s, preferably 60mm / s to 200mm / s; the conveying speed of the conveying mechanism in the cooling zone is 500mm / s to 3000mm / s, preferably 1000 to 2000mm / s. The annealing time of the press-formed curved glass in the annealing zone is controlled not to exceed 10s, preferably 4s to 6s.

[0046] Specifically, Figure 3 As shown, the middle punch 2 is installed on the furnace roof 6 of the heating furnace through the middle lifting member 22. The side punch 3 is installed on the furnace roof 6 of the heating furnace through the side lifting member 33. The die 1 is annular, that is, the die 1 has a suspended area that is not pressed against the middle punch 2. Figure 4 As shown, the ring width W of the die 1 (i.e., the distance between the inner edge 11 of the die 1 and its outer edge 12) is 20 mm to 50 mm, preferably 25 mm to 40 mm. The die 1 is installed on the furnace bottom 7 of the heating furnace through the die lifting member 13. The conveying mechanism and the forming positioning ring 4 are arranged in the suspended area of ​​the die 1. Among them, the forming positioning ring 4 is installed on the furnace bottom 7 of the heating furnace through the positioning lifting member 42; the conveying mechanism includes a plurality of conveying rollers arranged along its conveying direction, and a plurality of conveying rollers are located on the inner side of the forming positioning ring 4. The inner edge 11 of the die 1 is located on the inner side of the outer edge 21 of the middle punch 2, so that the edge of the middle punch 2 can press against the die 1 to press the peripheral area 511 of the middle area 51. The distance d between the outer edge 41 of the forming positioning ring 4 and the edge 54 of the glass 5 to be formed is 10 mm to 50 mm, preferably 15 mm to 25 mm.

[0047] like Figures 1 to 3As shown, the middle punch 2 is lifted and positioned to its initial pressing position before pressing, and the side punch 3 is also lifted and positioned to its position to be pressed, so that after the middle punch 2 is pressed, it can be lowered to its initial pressing position within a preset time to press the side area 52; wherein, as Figure 4 As shown, the position to be pressed of the side punch 3 is higher than the initial pressing position of the middle punch 2, and the height difference h is 1mm to 10mm, preferably 1mm to 5mm. Figure 1 As shown, the glass 5 to be formed is transported to the top of the forming positioning ring 4 by the transport mechanism. Figure 2 As shown, the glass 5 to be formed is lifted upward by the forming positioning ring 4 by 5 mm to 25 mm, preferably by 10 mm to 20 mm, so that the glass 5 to be formed is separated from the conveying mechanism; Figure 3 As shown, the female mold 1 is then raised until the female mold 1 holds up the glass 5 to be formed and continues to be raised so that the female mold 1 contacts the lowest point of the middle male mold 2. At the same time, the molding positioning ring 4 is lowered to a certain height to ensure that the molding positioning ring 4 does not interfere with the subsequent pressing of the middle male mold 2. Figure 5 As shown, the middle punch 2 is then lowered to a certain height for pressing, and at the same time, the middle punch 2 is lowered from its position to be pressed synchronously with the middle punch 2 and the height difference h is always maintained with the middle punch 2; Figure 6 As shown, after the middle punch 2 completes the pressing, the side punch 3 descends to its initial pressing position within a preset time and contacts the side area 52, and continues to descend until the side punch 3 and the side area 52 are completely fitted together, thereby completing the pressing of the glass 5 to be formed.

[0048] like Figure 3 and Figure 5 As shown, in the embodiment of the present invention, during the process of the middle punch 2 pressing the middle area 51, the time required for the middle punch 2 to descend from its lowest point contacting the glass 5 to be formed to the outer edge 21 of the middle punch 2 contacting the glass 5 to be formed is less than or equal to 0.1s, that is, the time difference from the middle punch 2 starting to contact the glass 5 to the middle area 51 of the glass 5 to be formed is reduced to less than 0.1s, so that the stress can be more evenly distributed in the entire middle area 51, which is conducive to the stretching of wrinkles in the entire middle area 51, thereby avoiding stress concentration in the peripheral area 511 of the middle area 51, and avoiding the wrinkles in the peripheral area 511 of the middle area 51 being too high and difficult to expand and disperse. Among them, the peripheral area 511 of the middle area 51 is the area close to the edge of the middle area 51, that is, the area pressed by the edge of the middle punch 2.

[0049] In addition to heating the edge region 52, in an embodiment of the present invention, during the process of the edge punch 3 pressing the edge region 52, it also includes: heating the peripheral region 511 of the middle region 51, so that the peripheral region 511 of the middle region 51 also exhibits higher molecular thermal motion under the dual effects of pressure and temperature, which is beneficial to the outward expansion and dispersion of the wrinkles in the peripheral region 511 of the middle region 51.

[0050] like Figure 4 As shown, in the embodiment of the present invention, there is a pressing gap e between the inner edge 31 of the side punch 3 and the outer edge 21 of the middle punch 2, and the glass to be formed 5 has a buffer area 53 corresponding to the pressing gap e between the side area 52 and the middle area 51; in the process of the side punch 3 pressing the side area 52, it also includes: heating the buffer area 53. By setting the pressing gap e, it is not only beneficial for the middle punch 2 and the side punch 3 to move relative to each other in the height direction without interfering with each other, but also allows the glass to be formed 5 to form a buffer area 53 that is not pressed by the side punch 3 and the middle punch 2, and the heated buffer area 53 is used to connect the middle area 51 and the side area 52, providing a space for the wrinkles in the peripheral area 511 of the middle area 51 and the wrinkles in the side area 52 to stretch and disperse, so that the wrinkles can be stretched and distributed more evenly, further improving the optical properties of the curved glass.

[0051] Specifically, the heating temperature is 550° C. to 700° C., that is, the temperature of heating the edge region 52, the peripheral region 511 of the middle region 51, and the buffer region 53 is 550° C. to 700° C., preferably 600° C. to 650° C. The width of the pressing gap e (that is, the width of the buffer region 53) is less than 10 mm, preferably 4 mm to 6 mm.

[0052] like Figure 4 As shown, in this embodiment, the heating structure is provided on the concave mold 1 to achieve heating of the edge area 52, the peripheral area 511 of the middle area 51, and the buffer area 53. The heating structure can be provided inside the concave mold 1. The heating form of the heating structure includes but is not limited to electromagnetic heating, heating rod heating, and infrared heating. The heating area of ​​the heating structure includes the area between the inner edge 11 of the concave mold 1 and the edge 54 of the glass 5 to be formed. The spacing c between the inner edge 11 of the concave mold 1 and the edge 54 of the glass 5 to be formed is 15 mm to 25 mm.

[0053] In another embodiment, the heating structure may also be disposed at corresponding positions of the edge punch 3 and the middle punch 2 to achieve heating of the edge region 52 , the peripheral region 511 of the middle region 51 , and the buffer region 53 .

[0054] like Figure 7As shown, in an embodiment of the present invention, the middle punch 2 is provided with a middle adsorption structure, which is connected to the middle vacuum structure; the side punch 3 is provided with a side adsorption structure, which is connected to the side vacuum structure; after the side punch 3 presses the side area 52 into shape, the curved glass forming method also includes the following steps: the side vacuum structure vacuums the side adsorption structure so that the side adsorption structure adsorbs and fits the side area 52 to the side punch 3; the vacuum state of the side adsorption structure is maintained, and at the same time, the middle vacuum structure vacuums the middle adsorption structure so that the middle adsorption structure adsorbs and fits the middle area 51 to the middle punch 2, and the vacuum degree of the middle adsorption structure is controlled to be less than the vacuum degree of the side adsorption structure, thereby completing the forming of the curved glass. After the glass 5 to be formed is pressed and formed, the edge area 52 of the glass 5 to be formed is first adhered and adsorbed to the edge punch 3 by utilizing the vacuum adsorption force, and then the middle area 51 of the glass 5 to be formed is adhered and adsorbed to the middle punch 2, and the vacuum degree is controlled to make the adsorption force on the edge area 52 greater than the adsorption force on the middle area 51, thereby achieving the final shaping of the curved glass, making the overall curved glass smoother, and further improving the optical performance of the curved glass.

[0055] Specifically, the lower surface of the middle punch 2 matches the shape to be formed in the middle area 51; the lower surface of the side punch 3 matches the shape to be formed in the side area 52. The middle adsorption structure of the middle area 51 includes a middle vacuum cavity 23 provided in the middle punch 2 and a middle adsorption hole provided on the lower surface of the middle punch 2 and connected to the middle vacuum cavity 23, and the middle vacuum pumping structure includes a middle vacuum pumping pipeline connected to the middle vacuum cavity 23; the side adsorption structure of the side area 52 includes a side vacuum cavity 34 provided in the side punch 3 and a side adsorption hole provided on the lower surface of the side punch 3 and connected to the side vacuum cavity 34, and the side vacuum pumping structure includes a side vacuum pumping pipeline connected to the side vacuum cavity 34. The middle vacuum pumping pipeline and the side vacuum pumping pipeline are independently arranged to control the vacuum degree of the middle vacuum cavity 23 and the side vacuum cavity 34 respectively.

[0056] Implementation Method 2

[0057] like Figures 1 to 7 As shown, the present invention also provides a pressing mold. Since the principle of solving the problem by the pressing mold is similar to the curved glass forming method in Implementation Mode 1, the implementation of the device can refer to the implementation of the curved glass forming method in Implementation Mode 1, and the repeated parts will not be repeated.

[0058] The pressing mold of the present invention comprises: a die 1 for placing the glass 5 to be formed; a middle punch 2, which can be raised and lowered above the die 1; a side punch 3, which can be raised and lowered above the die 1 and is located around the middle punch 2; wherein the pressing mold can successively form an inner mold pressing state and an outer mold pressing state; in the inner mold pressing state, there is a gap between the side punch 3 and the glass 5 to be formed, and the middle punch 2 cooperates with the die 1 to press the middle area 51 of the glass 5 to be formed; in the outer mold pressing state, the middle punch 2 maintains the pressing state, and the side punch 3 cooperates with the die 1 to press the side area 52 of the glass 5 to be formed; wherein the pressing mold is also provided with a heating structure, and the heating area of ​​the heating structure can cover the side area 52.

[0059] Specifically, the heating structure is arranged on the concave mold 1. The concave mold 1 is annular, and the inner edge 11 of the concave mold 1 is located inside the outer edge 21 of the middle convex mold 2; the heating area of ​​the heating structure includes the area between the inner edge 11 of the concave mold 1 and the edge 54 of the glass 5 to be formed. The distance between the inner edge 11 of the concave mold 1 and the edge 54 of the glass 5 to be formed is 15 mm to 25 mm.

[0060] In the embodiment of the present invention, the die 1 can be raised and lowered, and the pressing die further comprises a molding positioning ring 4 , which is raised and lowered on the inner side of the die 1 .

[0061] In the embodiment of the present invention, there is a pressing gap between the inner edge 31 of the side punch 3 and the outer edge 21 of the middle punch 2, and the glass 5 to be formed has a buffer area 53 corresponding to the pressing gap between the side area 52 and the middle area 51.

[0062] In an embodiment of the present invention, the width of the pressing gap is less than 10 mm.

[0063] In the embodiment of the present invention, the edge 54 of the glass to be formed 5 is located inside the outer edge 32 of the edge punch 3, and the distance between the edge 54 of the glass to be formed 5 and the outer edge 32 of the edge punch 3 is 5 mm to 40 mm.

[0064] In the embodiment of the present invention, the outer edge 21 of the middle punch 2 is located inside the edge 54 of the glass 5 to be formed, and the distance between the outer edge 21 of the middle punch 2 and the edge 54 of the glass 5 to be formed is 10 mm to 40 mm.

[0065] In an embodiment of the present invention, the middle punch 2 is provided with a middle adsorption structure, which is connected to the middle vacuum structure; the side punch 3 is provided with a side adsorption structure, which is connected to the side vacuum structure; the pressing mold can successively form a first adsorption state and a second adsorption state; in the first adsorption state, the side adsorption structure is vacuumed by the side vacuum structure so that the side area 52 is adsorbed and fitted with the side punch 3; in the second adsorption state, the side adsorption structure maintains a vacuum state, the middle adsorption structure is vacuumed by the middle vacuum structure so that the middle area 51 is adsorbed and fitted with the middle punch 2, and the vacuum degree of the middle adsorption structure is less than the vacuum degree of the side adsorption structure.

[0066] The above are only several embodiments of the present invention. Those skilled in the art may make various changes or modifications to the embodiments of the present invention based on the contents disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims

1. A method for forming curved glass, characterized in that: The following steps are involved: Placing the glass to be formed on the concave mold; The middle convex mold cooperates with the concave mold to press the middle area of ​​the glass to be formed; After the middle punch has pressed the middle area into shape, the pressing state of the middle punch is maintained, and at the same time, the side punch cooperates with the concave mold to press the side area of ​​the glass to be formed, and heats the side area.

2. The method for forming curved glass according to claim 1, wherein: Before placing the glass to be formed on the concave mold, the curved glass forming method further comprises: preheating the glass to be formed to 500° C. to 750° C.

3. The method for forming curved glass according to claim 1, wherein: During the process of the middle punch pressing the middle area, the time required for the middle punch to descend from its lowest point contacting the glass to be formed to the outer edge of the middle punch contacting the glass to be formed is less than or equal to 0.1 s.

4. The method for forming curved glass according to claim 1, wherein: Before the middle punch presses the middle area, the middle punch is lifted and positioned to its initial pressing position before pressing, and the side punch is also lifted and positioned to its position to be pressed, wherein: The position to be pressed of the edge punch is higher than the initial pressing position of the middle punch, and the height difference h is 1 mm to 10 mm.

5. The method for forming curved glass according to claim 1, wherein: During the process of the edge punch pressing the edge region, the process also includes: heating the surrounding area of ​​the middle region.

6. The method for forming curved glass according to claim 5, wherein: There is a pressing gap between the inner edge of the edge convex mold and the outer edge of the middle convex mold, and the glass to be formed has a buffer area corresponding to the pressing gap between the edge area and the middle area; During the process of the edge punch pressing the edge area, the method further includes: heating the buffer area.

7. The method for forming curved glass according to any one of claims 1, 5 and 6, characterized in that: The heating temperature is 550°C to 700°C.

8. The method for forming curved glass according to claim 1, wherein: The middle convex mold is provided with a middle adsorption structure, and the middle adsorption structure is connected to the middle vacuum structure; the side convex mold is provided with a side adsorption structure, and the side adsorption structure is connected to the side vacuum structure; after the side convex mold presses the side area into shape, the curved glass forming method further includes the following steps: The edge vacuuming structure vacuums the edge adsorption structure so that the edge adsorption structure adsorbs the edge area to fit the edge convex mold; The edge adsorption structure is maintained in a vacuum state, while the middle vacuuming structure vacuums the middle adsorption structure so that the middle adsorption structure adsorbs the middle area to fit the middle convex mold, and the vacuum degree of the middle adsorption structure is controlled to be lower than the vacuum degree of the edge adsorption structure.

9. A pressing die, characterized in that: include: The concave mold is used to place the glass to be formed; A middle male die is arranged above the female die in a liftable manner; The side punch is movably disposed above the die and around the middle punch; The pressing mold can successively form an inner mold pressing state and an outer mold pressing state; in the inner mold pressing state, there is a gap between the edge convex mold and the glass to be formed, and the middle convex mold cooperates with the concave mold to press the middle area of ​​the glass to be formed; in the outer mold pressing state, the middle convex mold maintains a pressing state, and the edge convex mold cooperates with the concave mold to press the edge area of ​​the glass to be formed; Wherein, the pressing mold is also provided with a heating structure, and the heating area of ​​the heating structure can cover the edge area.

10. The pressing die according to claim 9, wherein The heating structure is arranged on the concave mold.

11. The pressing die according to claim 10, wherein: The concave mold is annular, and the inner edge of the concave mold is located inside the outer edge of the middle convex mold; the heating area of ​​the heating structure includes the area between the inner edge of the concave mold and the edge of the glass to be formed.

12. The pressing die according to claim 11, wherein The distance between the inner edge of the concave mold and the edge of the glass to be formed is 15 mm to 25 mm.

13. The pressing die according to claim 11, wherein The female mold can be raised and lowered, and the pressing mold further comprises a molding positioning ring, which can be raised and lowered and is located at the inner side of the female mold.

14. The pressing die according to any one of claims 9 to 13, characterized in that A pressing gap is provided between the inner edge of the side convex mold and the outer edge of the middle convex mold, and the glass to be formed has a buffer area corresponding to the pressing gap between the side area and the middle area.

15. The pressing die according to claim 14, wherein: The width of the pressing gap is less than 10 mm.

16. The pressing die according to any one of claims 9 to 13, characterized in that The edge of the glass to be formed is located inside the outer edge of the edge convex mold, and the distance between the edge of the glass to be formed and the outer edge of the edge convex mold is 5 mm to 40 mm.

17. The pressing die according to any one of claims 9 to 13, characterized in that The outer edge of the middle convex mold is located inside the edge of the glass to be formed, and the distance between the outer edge of the middle convex mold and the edge of the glass to be formed is 10 mm to 40 mm.

18. The pressing die according to claim 9, wherein: The middle convex mold is provided with a middle adsorption structure, and the middle adsorption structure is connected with the middle vacuum pumping structure; the side convex mold is provided with a side adsorption structure, and the side adsorption structure is connected with the side vacuum pumping structure; The pressing mold can successively form a first adsorption state and a second adsorption state; in the first adsorption state, the edge adsorption structure is vacuumed by the edge vacuum structure so that the edge area and the edge punch are adsorbed and fitted; in the second adsorption state, the edge adsorption structure maintains a vacuum state, and the middle adsorption structure is vacuumed by the middle vacuum structure so that the middle area and the middle punch are adsorbed and fitted, and the vacuum degree of the middle adsorption structure is lower than the vacuum degree of the edge adsorption structure.

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