Lower die structure and hot bending die

Abstract

The utility model relates to the technical field of dies, and discloses a lower die structure and a hot bending die. The lower die structure comprises a lower die body and a positioning block; a hot bending cavity and a material supporting inclined platform are arranged on the die assembly face of the lower die body, the material supporting inclined platform is close to the hot bending cavity and located on the symmetrical center line of the hot bending cavity, and the material supporting inclined platform inclines towards the hot bending cavity and is in arc transition with the hot bending cavity. The positioning block is arranged on the lower die body and located on the side, away from the hot bending cavity, of the inclined material supporting platform. Wherein in the extension direction of the symmetrical center line of the hot bending cavity, the distance between the side, close to the material supporting inclined platform, of the positioning block and the hot bending cavity is L, L is larger than or equal to 6 mm and smaller than or equal to 8 mm, the inclination angle of the material supporting inclined platform is C1, and C1 is smaller than 45 degrees. According to the lower die structure disclosed by the invention, wrinkles and poor die marks of the hot bending cavity in the material supporting inclined platform area are effectively avoided, and the quality of a finished product is improved.

Description

Technical Field

[0001] The present application belongs to the field of mold technology, and specifically relates to a lower mold structure and a hot bending mold. Background Art

[0002] Virtual reality technology (English name: Virtual Reality, abbreviated as VR) has been recognized and loved by more and more people. Among them, VR glasses are one of the core components of VR equipment. VR glasses are commonly made of glass or resin, and glass has become the primary choice of VR glasses material due to its excellent wear resistance and light transmittance. However, VR glass glasses have a special shape and the 3D hot bending molding process is more difficult than other products. The glass sheet is prone to breaking when the mold is covered, especially in the middle of the corner of the product's nose bridge. The product is prone to pile-up and squeezing, resulting in poor product appearance, wrinkles and poor mold printing. Using the existing traditional mold structure and process debugging methods, the appearance and size of the product after hot bending cannot meet the customer's quality requirements. Utility Model Content

[0003] The purpose of this application is to provide a lower mold structure and a hot bending mold to solve the problem that the existing traditional mold structure is prone to material piling and squeezing in the middle of the corner of the product's nose bridge, resulting in poor product appearance, wrinkles and poor mold printing.

[0004] In order to achieve the above-mentioned object, the first aspect of the present application provides a lower mold structure, including a lower mold body and a positioning block;

[0005] The die surface of the lower die body is provided with a hot bending cavity and a material supporting inclined platform, the material supporting inclined platform is close to the hot bending cavity and is located on the symmetric center line of the hot bending cavity, the material supporting inclined platform is inclined toward the hot bending cavity and transitions to the hot bending cavity in an arc;

[0006] The positioning block is provided on the lower mold body and is located on a side of the supporting inclined platform away from the hot bending cavity;

[0007] Among them, along the extension direction of the symmetrical center line of the hot bending cavity, the distance from the side of the positioning block close to the material supporting inclined platform to the hot bending cavity is L, 6mm≤L≤8mm, and the inclination angle of the material supporting inclined platform is C1, C1<45°.

[0008] As a further improvement of the above technical solution:

[0009] In some embodiments, the inclination angle C1 of the supporting inclined platform satisfies: 20°≤C1≤24°.

[0010] In some embodiments, a side of the hot bending cavity away from the supporting inclined platform is defined as a forehead side, and a margin section and a slope section are sequentially provided on the forehead side in a direction extending outward from the hot bending cavity, and arc transitions are formed between the forehead side, the margin section, and the slope section;

[0011] The slope section is inclined toward the hot bending cavity, and the inclination angle of the slope section is C2, and satisfies: 34°≤C2≤38°.

[0012] In some embodiments, a margin section is provided at the outer edge of the hot bending cavity, and the width of the margin section is 1.8 mm to 2.2 mm.

[0013] In some embodiments, outer edges of both ends of the hot bending cavity are provided with a sliding transition profile, the sliding transition profile comprising a first profile segment, a second profile segment, and a third profile segment connected in sequence, the first profile segment being located on a side of the second profile segment away from the hot bending cavity;

[0014] The first contour segment, the second contour segment and the third contour segment are transitioned by arcs, the first contour segment is a plane, the second contour segment is a sloped surface, and the third contour segment transitionally connects the second contour segment and the hot bending cavity.

[0015] In some embodiments, the inclination angle of the second contour segment is C3, and satisfies: C3 = 45° ± 3°.

[0016] In some embodiments, a first temperature measuring hole is provided on the lower mold body.

[0017] To achieve the above-mentioned object, the second aspect of the present application further provides a hot bending mold, comprising an upper mold structure and a lower mold structure provided according to the first aspect, wherein the lower mold structure is arranged in alignment with the upper mold structure, and in a mold closing state, the upper mold structure is combined with the lower mold structure and is located above the lower mold structure;

[0018] Wherein, the upper mold structure is provided with a mold core portion protruding toward the hot bending cavity, and a second temperature measuring hole is provided on the upper mold structure.

[0019] In some embodiments, a groove is provided on a side of the upper mold structure facing away from the lower mold structure and is concave toward the mold core portion.

[0020] In some embodiments, the wall thickness formed between the bottom of the groove and the surface of the mold core facing the hot bending cavity is h, which satisfies: 8mm≤h≤10mm.

[0021] Compared with the prior art, the present application provides a lower mold structure and a hot bending mold, wherein the lower mold structure is provided with a material supporting inclined platform on the mold surface, and the material supporting inclined platform is inclined toward the hot bending cavity and transitions to the arc of the hot bending cavity, and then a positioning block is provided on the side of the material supporting inclined platform away from the hot bending cavity to limit the hot bending product. Further, the distance from the side of the positioning block close to the material supporting inclined platform to the hot bending cavity is designed to be L, 6mm≤L≤8mm, and the inclination angle of the material supporting inclined platform is designed to be C1, C1<45°. In this way, when applied to the hot bending mold for hot bending of glass products, the distance L design can ensure that there is enough space on the material supporting inclined platform to store residual material when hot bending the glass products, and the inclination angle C1 can prevent the stored residual material (softened product) from sliding down too quickly, thereby effectively avoiding the occurrence of wrinkles in the hot bending cavity in the material supporting inclined platform area and the occurrence of poor mold printing, thereby improving the quality of the finished product.

[0022] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without inventive work. In the drawings:

[0024] Figure 1 A schematic diagram of the product structure formed by hot bending using the hot bending mold provided in an embodiment of the present application;

[0025] Figure 2 This is an exploded schematic diagram of a hot bending mold provided in an embodiment of the present application;

[0026] Figure 3 for Figure 2 A top view of the lower die structure in the hot bending die shown;

[0027] Figure 4 for Figure 3 Cross-sectional view along the AA axis;

[0028] Figure 5 A schematic diagram of the three-dimensional structure of the hot bending mold provided in an embodiment of the present application in a mold closing state;

[0029] Figure 6 for Figure 5 Cross-sectional view along the BB direction;

[0030] Figure 7 for Figure 5 Cross-sectional view in the middle DD direction;

[0031] Figure 8 for Figure 7 A partial enlarged schematic diagram of point E in the middle.

[0032] Description of Reference Numerals

[0033] 10. VR glass products; 11. Nose bridge; 12. Forehead;

[0034] 100, lower mold structure; 110, lower mold body; 111, closing surface; 112, hot bending cavity; 112a, nose bridge area; 112b, forehead side; 1120, support tilting platform; 1121, margin section; 1122, slope section; 1123, sliding transition profile; 1124, first profile section; 1125, second profile section; 1126, third profile section; 113, first temperature measuring hole; 120, positioning block; 130, first positioning plate; 140, second positioning plate;

[0035] 200, upper mold structure; 201, groove; 210, second temperature measuring hole; 220, mold core part. DETAILED DESCRIPTION

[0036] The following describes the specific embodiments of the present application in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application and are not intended to limit the present application.

[0037] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with exemplary embodiments.

[0038] Example 1

[0039] like Figure 2 As shown, this embodiment provides a lower mold structure 100 for use in a hot bending mold, which can be used in a 3D hot bending process for glass products, such as hot bending a glass sheet into a VR glass product 10. Therefore, to more clearly describe the technical solution of this application, this application uses the hot bending of the VR glass product 10 as an example for illustration.

[0040] like Figure 1 As shown, relative to the human facial structure, a nose bridge portion 11 is formed at the midline position on the lower side of the VR glass product 10 , and a forehead portion 12 is opposite to the nose bridge portion 11 .

[0041] It should be noted that due to the special shape of VR glass product 10, the 3D hot bending forming process is more difficult than other products. The glass sheet is prone to breakage when covering the mold, especially in the middle of the corner of the nose bridge of the product. The product is prone to stacking and squeezing, resulting in poor product appearance, wrinkles and poor mold printing.

[0042] To solve the above problems, Figure 2 、 Figure 5 As shown, the lower mold structure 100 provided in this embodiment includes a lower mold body 110 and a positioning block 120. The lower mold structure 100 is typically used in combination with an upper mold structure 200, i.e., for mold closing and mold separation. In this embodiment, the surface of the lower mold structure 100 facing the upper mold structure 200 is defined as the mold closing surface 111.

[0043] In this embodiment, if Figure 3 、 Figure 4 As shown, the die surface 111 of the lower mold body 110 is provided with a heat-bending cavity 112 and a material-supporting tilting platform 1120. The shape of the heat-bending cavity 112 is consistent with that of the VR glass product 10. The heat-bending cavity 112 has a symmetrical centerline and is bent in the middle of one side to form a nose bridge area 112a corresponding to the nose bridge portion 11 of the VR glass product 10. The material-supporting tilting platform 1120 is located near the heat-bending cavity 112 and on its symmetrical centerline. The material-supporting tilting platform 1120 is inclined toward the heat-bending cavity 112 and forms a circular transition with the heat-bending cavity 112.

[0044] In some embodiments, the material supporting tilting platform 1120 is integrally formed with the lower mold body 110 , that is, when manufacturing the lower mold body 110 , a raised platform is constructed on the mold surface 111 , and the raised platform serves as the material supporting tilting platform 1120 .

[0045] In this embodiment, the support tilting platform 1120 is a separate structure from the lower mold body 110. This allows the tilting angle of the support tilting platform 1120 to be machined first before assembly with the lower mold body 110, improving machining accuracy. Furthermore, the support tilting platform 1120 can be made of other easily machined or more economical materials, making it easier to replace later and reducing costs.

[0046] Furthermore, a positioning block 120 is provided on the lower mold body 110 and is located on the side of the support tilting platform 1120 away from the bending cavity 112. The positioning block 120 facilitates positioning of the support tilting platform 1120, provides positioning for the glass sheet, and prevents the glass from flowing away from the bending cavity 112 during bending, thereby ensuring bending quality.

[0047] Please also refer to Figure 4 In this embodiment, along the extension direction of the symmetrical center line of the hot bending cavity 112, the distance from the side of the positioning block 120 close to the material supporting inclined platform 1120 to the hot bending cavity 112 is L, 6mm≤L≤8mm, and the inclination angle of the material supporting inclined platform 1120 is C1, C1<45°.

[0048] See also Figure 1 、 Figure 2 、 Figure 3 and Figure 4 It should be noted that due to the special curvature of the nose bridge 11 of the VR glass product 10, based on the analysis of the wrinkle problem on the nose bridge 11, a material support tilting platform 1120 is added to the nose bridge area of ​​the hot bending cavity 112 on the lower mold body 110. The material support tilting platform 1120 is connected to the hot bending cavity 112 and then tilted. Extensive experiments have found that if the tilt angle C1 is greater than 45°, the excess material of the product will slide down rapidly during hot bending, affecting product quality. In addition, if the excess material in the nose bridge area is greater than 8mm, the nose bridge 11 of the VR glass product 10 cannot be pressed; if the excess material in the nose bridge area is less than 6mm, it is easy to pile up, resulting in wrinkles. In this way, when the hot bending mold is used to bend glass products, the distance L design can ensure that there is enough space for storing residual materials on the material support tilting platform 1120 when the glass products are hot bent. The tilting angle C1 can prevent the stored residual materials (softened products) from sliding down too quickly, thereby effectively avoiding the formation of wrinkles in the hot bending cavity 112 in the material support tilting platform 1120 area and the generation of poor mold printing, thereby improving the quality of the finished product.

[0049] Furthermore, in some embodiments, the tilt angle C1 of the supporting tilt platform 1120 satisfies: 20°≤C1≤24°. When the tilt angle is between 20° and 24°, the nose bridge portion 11 of the VR glass product 10 is better formed.

[0050] See also Figure 3 and Figure 4 To further describe the technical solution of this embodiment, the side of the heat-bending cavity 112 away from the supporting inclined platform 1120 is defined as the forehead side 112b (corresponding to the forehead portion 12 of the VR glass product 10). The forehead side 112b is sequentially provided with a margin section 1121 and a slope section 1122 in the direction extending out of the heat-bending cavity 112. The forehead side 112b, the margin section 1121, and the slope section 1122 have arc transitions therebetween.

[0051] Furthermore, the slope section 1122 is inclined toward the hot bending cavity 112, and the inclination angle of the slope section 1122 is C2, and satisfies: 34°≤C2≤38°. It should be noted that, because the contour of the forehead portion 12 of the existing VR glass product 10 is relatively steep, and the edge contour of the product is about 88°, the product is prone to mold marks and poor extrusion lines during the molding process. In this embodiment, after hot bending verification, the best design scheme is obtained, and the margin section 1121 is extended according to the product contour on the mold forehead side of the hot bending cavity 112, and then the slope section 1122 with an inclination angle of C2 is designed. Among them, the inclination angle C2 of 36° is the best solution. Optionally, the appropriate angle of the inclination angle C2 can be between 34° and 38°. Above 38°, the product slides down too fast during molding, which is prone to poor mold marks. Below 34°, the product is prone to poor extrusion lines.

[0052] Optionally, the outer edge of the hot-bending cavity 112 is provided with a margin section 1121 (excluding the nose bridge area 112a), and the width of the margin section 1121 is 1.8 mm to 2.2 mm.

[0053] Please also refer to Figure 7 and Figure 8 , further, the two ends of the hot bending cavity 112 (such as Figure 3 The outer edge of the upper and lower ends (as shown) is provided with a sliding transition profile 1123, which includes a first profile segment 1124, a second profile segment 1125 and a third profile segment 1126 connected in sequence. The first profile segment 1124 is located on the side of the second profile segment 1125 away from the hot bending cavity 112.

[0054] Among them, the first contour segment 1124, the second contour segment 1125 and the third contour segment 1126 are transitioned by arcs. The first contour segment 1124 is a plane, the second contour segment 1125 is a sloped surface, and the third contour segment 1126 transitionally connects the second contour segment 1125 and the hot bending cavity 112.

[0055] In this embodiment, the third contour segment 1126 is the margin segment 1121 described above.

[0056] Optionally, the inclination angle of the second contour segment 1125 is C3, and satisfies: C3 = 45°±3°.

[0057] It should be noted that because the two ends of the product are prone to deviation during molding, resulting in poor pressing lines, three sections of sliding contours with different angles are designed at the sliding positions of the two ends of the hot bending cavity 112. The first contour section 1124 is used to position the glass sheet and is designed to be flat. After the upper mold structure 200 is covered, the force is balanced and the glass sheet slides down in unison after softening; the second contour section 1125 is inclined at 45 degrees to follow the contours of the forehead 12 and the nose bridge 11 (see Figure 1 ), and also to improve the middle material piling after the product softens to avoid poor pressing lines; the third contour segment 1126 and the hot bending cavity 112 extend by 2mm, because the calculated residual material of the product after hot bending is 2mm, and then it is smoothly connected with the second contour segment 1125, mainly to improve the deviation of the two ends of the product and poor pressing lines.

[0058] It can be further understood that due to the special shape of the product, the arch height of the 3D product after hot bending exceeds 47mm. If the temperature of the machine and the mold is uneven, it will cause serious deviation during product molding, resulting in poor mold print and contour. In order to improve the defects, a first temperature measuring hole 113 is set on the back bottom surface of the lower mold body 110. The first temperature measuring hole 113 can detect the actual temperature of the lower mold body 110 and the product, and the difference from the set temperature of the machine, which is convenient for debugging the temperature uniformity of the hot bending process and can improve the poor mold print and contour of the product.

[0059] Example 2

[0060] See also Figures 1 to 8 This embodiment provides a hot bending mold for hot bending a glass sheet into a VR glass product 10.

[0061] See also Figure 2 、 Figure 3 and Figure 5 In this embodiment, the hot bending mold includes an upper mold structure 200 and a lower mold structure 100 provided according to the first embodiment. The lower mold structure 100 is arranged in an aligned manner with the upper mold structure 200. In the closed mold state, the upper mold structure 200 is combined with the lower mold structure 100 and positioned above the lower mold structure 100; in the open mold state, the upper mold structure 200 and the lower mold structure 100 are separated.

[0062] Please also refer to Figure 6 The upper mold structure 200 has a core portion 220 that protrudes toward the hot bending cavity 112, which is used to form the central curved area of ​​the product. A second temperature measuring hole 210 is provided on the upper mold structure 200. This hole can detect the actual temperature of the upper mold structure 200 and the product, and the difference between the actual temperature and the machine's set temperature. This facilitates temperature uniformity adjustment during the hot bending process and improves product impression and contour defects.

[0063] Please also refer to Figure 6 and Figure 7 In some embodiments, a recess 201 is formed on the side of the upper mold structure 200 facing away from the lower mold structure 100, corresponding to the mold core 220. This reduces the weight of the upper mold structure 200 on the glass sheet, thereby preventing the glass sheet from being crushed during hot bending. Of course, if the glass sheet needs to be thinned or enlarged, it is not necessary to hollow out the area corresponding to the product; other areas can be hollowed out.

[0064] Furthermore, the wall thickness between the bottom of the groove 201 and the surface of the mold core 220 facing the hot bending cavity 112 is h, where the following condition is satisfied: 8mm≤h≤10mm. It is understood that it is necessary to maintain uniform weight balance of the hot bending mold. For example, if the thickness of the surface contacting the product is less than 8mm, the mold will easily deform during the hot bending forming process. If the surface contacting the product is greater than 10mm, the increased weight will easily crush the glass sheet.

[0065] Optionally, the upper mold structure 200 is a graphite mold, which has better thermal and electrical conductivity, high strength, high temperature resistance and chemical corrosion resistance.

[0066] It should be noted that in this application, unless otherwise specified, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like used to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application.

[0067] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0068] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0069] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0070] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A lower mold structure, characterized in that: It comprises a lower mold body (110) and a positioning block (120); The die surface (111) of the lower die body (110) is provided with a hot bending cavity (112) and a material supporting inclined platform (1120), wherein the material supporting inclined platform (1120) is close to the hot bending cavity (112) and is located on the symmetrical center line of the hot bending cavity (112), and the material supporting inclined platform (1120) is inclined toward the hot bending cavity (112) and transitions to the hot bending cavity (112) in an arc shape; The positioning block (120) is arranged on the lower mold body (110) and is located on a side of the supporting tilting platform (1120) away from the hot bending cavity (112); Wherein, along the extension direction of the symmetrical center line of the hot bending cavity (112), the distance from the side of the positioning block (120) close to the material supporting inclined platform (1120) to the hot bending cavity (112) is L, 6mm≤L≤8mm, and the inclination angle of the material supporting inclined platform (1120) is C1, C1<45°.

2. The lower mold structure according to claim 1, characterized in that: The inclination angle C1 of the supporting inclined platform (1120) satisfies: 20°≤C1≤24°.

3. The lower mold structure according to claim 1, characterized in that: The side of the hot bending cavity (112) away from the supporting inclined platform (1120) is defined as the forehead side (112b), and the forehead side (112b) is sequentially provided with a margin section (1121) and a slope section (1122) in the direction of extending outward from the hot bending cavity (112), and circular arc transitions are formed between the forehead side (112b), the margin section (1121) and the slope section (1122); The slope section (1122) is inclined toward the hot bending cavity (112), and the inclination angle of the slope section (1122) is C2, and satisfies: 34°≤C2≤38°.

4. The lower mold structure according to claim 3, characterized in that: The outer edge of the hot bending cavity (112) is provided with a margin section (1121), and the width of the margin section (1121) is 1.8 mm to 2.2 mm.

5. The lower mold structure according to claim 1, characterized in that: The outer edges of both ends of the hot bending cavity (112) are provided with a sliding transition profile (1123), the sliding transition profile (1123) comprising a first profile segment (1124), a second profile segment (1125) and a third profile segment (1126) connected in sequence, the first profile segment (1124) being located on a side of the second profile segment (1125) away from the hot bending cavity (112); The first contour segment (1124), the second contour segment (1125) and the third contour segment (1126) are transitioned in a circular arc, the first contour segment (1124) is a plane, the second contour segment (1125) is a sloped surface, and the third contour segment (1126) transitionally connects the second contour segment (1125) and the hot-bending cavity (112).

6. The lower mold structure according to claim 5, characterized in that: The inclination angle of the second contour segment (1125) is C3, and satisfies: C3 = 45°±3°.

7. The lower mold structure according to any one of claims 1 to 6, characterized in that: The lower mold body (110) is provided with a first temperature measuring hole (113).

8. A hot bending mold, characterized in that: The invention comprises an upper mold structure (200) and a lower mold structure (100) according to any one of claims 1 to 7, wherein the lower mold structure (100) and the upper mold structure (200) are arranged in a counterposition manner, and in a mold closing state, the upper mold structure (200) is combined with the lower mold structure (100) and is located above the lower mold structure (100); The upper mold structure (200) is provided with a mold core portion (220) protruding toward the hot bending cavity (112), and a second temperature measuring hole (210) is provided on the upper mold structure (200).

9. The hot bending mold according to claim 8, characterized in that: A groove (201) is correspondingly provided on a side of the upper mold structure (200) facing away from the lower mold structure (100) and is recessed toward the mold core portion (220).

10. The hot bending mold according to claim 9, characterized in that: The wall thickness formed between the bottom of the groove (201) and the surface of the mold core part (220) facing the hot bending cavity (112) is h, which satisfies the following: 8mm≤h≤10mm.

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