Quick-change injection mold for optical structural component

Abstract

The invention discloses a quick-change injection mold for an optical structural member, and relates to the technical field of injection molding.The quick-change injection mold comprises an upper mold assembly, a lower mold assembly, a front mold core and a rear mold core, the upper mold assembly and the lower mold assembly are locked and connected through a first mold locking buckle, and the upper mold assembly comprises an upper mold plate; at least two first positioning rods which are distributed diagonally are mounted on the upper template; the lower die assembly comprises a lower die plate, at least two second positioning rods distributed diagonally are installed on the lower die plate, and the second positioning rods correspond to the first positioning rods one to one. A first positioning sleeve matched with the first positioning rod in an inserted mode is fixedly connected into the front mold core, a second positioning sleeve matched with the second positioning rod in an inserted mode is fixedly connected into the rear mold core, and the rear mold core and the front mold core are connected in a locked mode through a second mold locking buckle. The front mold core and the rear mold core are used for injection molding of a product with a water gap frame. The injection mold solves the problem that in the prior art, precision and rigidity are difficult to balance when optical structural parts related to injection molds are produced.

Description

Technical Field

[0001] This invention relates to the field of injection molding technology, and more particularly to a quick-change injection mold for optical structural components. Background Technology

[0002] With the increasing demands for optical performance in consumer electronics, automotive lighting, medical devices, and smart wearables, the demand for various precision optical structural components (such as lenses, light guides, optical lenses, and aspherical optical elements) is growing rapidly, exhibiting characteristics of high variety, small batches, and frequent iterations. Injection molding, due to its ability to efficiently and complexly mold polymer optical components, has become the core manufacturing process in this field. However, the production of optical structural components places extremely stringent requirements on molds and processes: extremely low molding internal stress must be ensured to avoid birefringence and optical distortion; extremely high cavity surface quality and dimensional accuracy must be achieved to guarantee optical surface shape; and highly uniform and stable melt flow is required to ensure the consistency of material optical properties (such as transmittance and refractive index).

[0003] In existing technologies, traditional integral injection molds, after optimization for a single optical component, can often meet the aforementioned quality requirements under specific conditions. However, when production tasks require frequent switching between optical components of different models, materials, or colors, traditional mold methods reveal serious efficiency bottlenecks. Optical component molding requires extremely high mold closing accuracy and rigidity to eliminate flash and ensure dimensional stability. After repeated disassembly and assembly, the interface between conventional quick-change mold bases and the mold core struggles to maintain the same positioning accuracy and clamping rigidity as integral molds; even minute gaps or deformations can lead to stress or contour errors in the optical component.

[0004] Therefore, existing injection molds for the production of optical structural components present a challenge in balancing precision and rigidity. Summary of the Invention

[0005] The purpose of this invention is to provide a quick-change injection mold for optical structural components, which solves the problem of balancing precision and rigidity in the production of optical structural components using existing injection molds.

[0006] To achieve this objective, the present invention adopts the following technical solution: A quick-change injection mold for optical structural components includes an upper mold assembly, a lower mold assembly, a front mold core, and a rear mold core. The upper mold assembly and the lower mold assembly are locked together by a first mold locking buckle. The upper mold assembly includes an upper template that is fastened to the front mold core by screws. At least two first positioning rods are installed on the upper template in a diagonally distributed manner. The lower mold assembly includes a lower template that is fastened to the rear mold core by screws. At least two second positioning rods are installed on the lower template in a diagonal arrangement, and the second positioning rods correspond one-to-one with the first positioning rods. The front mold core is fixedly connected to a first positioning sleeve that is inserted and engaged with the first positioning rod, and the rear mold core is fixedly connected to a second positioning sleeve that is inserted and engaged with the second positioning rod. The rear mold core and the front mold core are locked together by a second mold locking buckle. The front mold core and the rear mold core are used to injection mold a product with a sprue frame.

[0007] Optionally, the upper mold assembly is provided with a hot runner structure, the end face of the front mold core is provided with a branch channel and a first molding cavity, and the end face of the rear mold core is provided with a connected second molding cavity and a third molding cavity. The hot runner structure is used to allow fluid to flow to the branch channel so that the fluid fills the first molding cavity, the second molding cavity and the third molding cavity, and obtains a product with a sprue frame.

[0008] Optionally, the hot runner structure includes a main channel, one end of the branch channel is connected to the main channel, and the other end of the branch channel is connected to the second molding cavity. The cross-sectional area of ​​the branch channel gradually decreases along the fluid flow direction. The second molding cavity is used to injection mold a sprue frame, and the first molding cavity and the third molding cavity are used to injection mold the product.

[0009] Optionally, the hot runner structure includes a first runner plate and a first stripper plate respectively fixedly installed in the upper template, and a second stripper plate and a second runner plate are sequentially stacked on the upper template. A runner pipe nested with the first stripper plate and the second stripper plate is pressed onto the first runner plate. The first ejector plate and the second ejector plate are used for ejecting the sprue from the injection mold. When the injection mold is being molded, the fluid passes sequentially through the second runner plate, the runner pipe, the first runner plate, the front mold core, and the rear mold core.

[0010] Optionally, the upper mold assembly further includes an upper fixing plate, a heat insulation plate, and guide pillars. The upper fixing plate is fixedly connected to the second flow channel plate. The upper fixing plate has a feed port, and the feed port is provided with a flange fixedly connected to the upper fixing plate. The guide post passes through the second flow channel plate, the second stripper plate, and the upper template in sequence, and a guide sleeve that is inserted and engaged with the guide post is installed on the lower template.

[0011] Optionally, the upper mold plate has a first liquid flow channel, the front mold core has a second liquid flow channel, the rear mold core has a third liquid flow channel, and the lower mold plate has a fourth liquid flow channel. The second liquid flow channel and the third liquid flow channel are arranged in a cross pattern. The first liquid flow channel, the second liquid flow channel, the third liquid flow channel and the fourth liquid flow channel are all used to contain coolant for circulation in order to balance the temperature of the injection mold during injection molding.

[0012] Optionally, the second stripper plate is fixedly installed with a mounting plate nested with the flow channel pipe. The mounting plate is provided with a hook embedded in the flow channel of the first flow channel plate. The hook is used to prevent the sprue in the first flow channel plate from falling off.

[0013] Optionally, the front mold core has an interconnected vent hole and a vent groove. The vent hole is connected to the second molding cavity, and the vent groove is located on the end face of the front mold core opposite to the rear mold core. The vent groove is connected to at least one side wall of the front mold core. The width of the vent groove is greater than the diameter of the vent hole.

[0014] Optionally, the lower mold assembly is provided with an ejector assembly, which is used to eject the product formed on the front mold core under external lifting force and return to the initial position under elastic force.

[0015] Optionally, the ejector assembly includes a first ejector plate and a second ejector plate stacked in sequence. The first ejector plate is fixedly connected to an ejector rod, and the second ejector plate is embedded with an ejector pin. A return spring is installed between the second ejector plate and the lower mold assembly. The first ejector plate and the second ejector plate are slidably connected to the lower mold assembly. The rear mold core is provided with a first through hole. One end of the ejector pin relative to the second ejector plate is inserted into the first through hole and abuts against the formed sprue frame.

[0016] Optionally, the side wall of the lower template is provided with a first lifting eye hole for installing a lifting eye, the side wall of the front mold core is provided with a first lifting hole, and the side wall of the rear mold core is provided with a second lifting hole; both the first lifting hole and the second lifting hole are used to hang the mold lifting bolts when replacing the front mold core and the rear mold core.

[0017] Optionally, the front mold core is fixedly installed with two diagonally distributed third positioning rods, and the rear mold core is fixedly installed with two diagonally distributed third positioning sleeves, with the third positioning rods and the third positioning sleeves being inserted into each other in a one-to-one correspondence; The two third positioning rods and the two first positioning sleeves are staggered at the four corners of the front mold core, and the two third positioning sleeves and the two second positioning sleeves are staggered at the four corners of the rear mold core.

[0018] Optionally, the lower mold assembly further includes a lower fixing plate, and two lower mold partitions are fixedly installed between the lower fixing plate and the lower template. One end of the first locking buckle is fastened to the lower template by screws.

[0019] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a quick-change injection mold for optical structural components. Through an innovative split-type and composite locking and positioning design, it solves the core problem of balancing mold-changing efficiency and molding quality in optical component production. The main body of the mold consists of an upper mold assembly and a lower mold assembly forming a stable external frame, and the overall locking force and rigidity are ensured by a first locking buckle. The core molding parts (front mold core and rear mold core) are independent modules, fixed to their respective templates by screws, and then locked again at the cavity level by a second locking buckle. This structure, which combines the rigidity of the overall frame with the precise locking of the modular cavity, allows the closure accuracy and deformation resistance of the entire mold system to be maintained like a single mold when frequently changing mold cores. This effectively eliminates problems such as flash, dimensional fluctuations, and increased internal stress caused by interface gaps or insufficient rigidity, thus meeting the stringent requirements of optical structural components for extremely low stress and high dimensional stability.

[0020] Because the mold core is an independent module that can be quickly assembled and disassembled while maintaining excellent molding performance, it allows for the switching of production of optical components of different models, materials, or colors on the same mold frame, with minimal impact on the optical quality of the final part. Stable locking and precise positioning provide a uniform and stable cavity environment for melt flow during injection molding; combined with the product design featuring a sprue frame, it facilitates balanced filling, further reducing problems such as orientation stress and refractive index unevenness caused by uneven or unstable flow, thereby ensuring the consistency and reliability of key optical properties such as transmittance and refractive index of the optical structural components. Therefore, this invention solves the problem of balancing precision and rigidity in the production of optical structural components using injection molds in existing technologies. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] The structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0023] Figure 1 A three-dimensional structural schematic diagram of a quick-change injection mold for optical structural components provided in an embodiment of the present invention; Figure 2 An exploded view of a quick-change injection mold for optical structural components provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a first partially exploded structure of a quick-change injection mold for optical structural components, provided by an embodiment of the present invention. Figure 4 This is a schematic diagram of a second partially exploded structure of a quick-change injection mold for optical structural components, provided by an embodiment of the present invention. Figure 5 for Figure 3 A magnified structural diagram at point A; Figure 6 This is a structural schematic diagram of a product with a sprue frame in a quick-change injection mold for optical structural components, provided as an embodiment of the present invention. Figure 7 A cross-sectional structural diagram of the upper mold assembly in a quick-change injection mold for optical structural components, provided as an embodiment of the present invention; Figure 8 This is an exploded structural diagram of the upper mold assembly in a quick-change injection mold for optical structural components, provided as an embodiment of the present invention. Figure 9 A half-sectional view of the first runner plate in a quick-change injection mold for optical structural components, provided as an embodiment of the present invention; Figure 10 A partial structural schematic diagram of a quick-change injection mold for optical structural components provided in an embodiment of the present invention; Figure 11 This is a bottom view of a quick-change injection mold for optical structural components provided in an embodiment of the present invention.

[0024] Illustration: 10. Upper mold assembly; 11. Upper template; 111. First runner channel; 112. Second lifting eye hole; 12. First positioning rod; 13. Hot runner structure; 131. First runner plate; 1311. First hot runner; 1312. Outlet; 132. First ejector plate; 1321. Seventh runner channel; 133. Second ejector plate; 1331. Fifth runner channel; 134. Second runner plate; 1341. Third hot runner channel; 1342. Sixth runner channel; 135. Runner tube; 1351. Second hot runner channel; 136. Mounting plate; 137. Hook; 14. Upper fixing plate; 141. Inlet; 15. Heat insulation plate; 16. Guide post; 17. Flange; 20. Lower mold assembly; 21. Lower template; 211. Guide sleeve; 212. Fourth fluid channel; 213. First lifting eye hole; 22. Second positioning rod; 23. Lower fixing plate; 24. Lower mold partition plate; 30. Front mold core; 31. First positioning sleeve; 32. Branch channel; 33. First molding cavity; 34. Second liquid channel; 35. First lifting hole; 36. Vent hole; 37. Vent groove; 38. Third positioning rod; 40. Rear mold core; 41. Second positioning sleeve; 42. Second molding cavity; 43. Third molding cavity; 44. Third fluid channel; 45. Second lifting hole; 46. Third positioning sleeve; 47. First through hole; 50. First mold-locking buckle; 60. Second locking buckle; 70. Ejector assembly; 71. First ejector plate; 72. Second ejector plate; 73. Ejector rod; 74. Ejector pin; 75. Return pin spring; 100. Product; 101. Sprue frame. Detailed Implementation

[0025] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0026] In the description of this invention, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component positioned centrally in the connection.

[0027] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0028] This invention provides a quick-change injection mold for optical structural components, such as... Figures 1 to 11 As shown, it includes an upper mold assembly 10, a lower mold assembly 20, a front mold core 30, and a rear mold core 40. The upper mold assembly 10 and the lower mold assembly 20 are locked together by a first mold locking buckle 50. The upper mold assembly 10 includes an upper template 11 that is fastened to the front mold core 30 by screws. At least two first positioning rods 12 are installed on the upper template 11 in a diagonally distributed manner. The lower mold assembly 20 includes a lower template 21 that is fastened to the rear mold core 40 by screws. At least two second positioning rods 22 are installed on the lower template 21 in a diagonal arrangement, and the second positioning rods 22 correspond one-to-one with the first positioning rods 12. The front mold core 30 has a first positioning sleeve 31 fixedly connected to it, which engages with the first positioning rod 12. The rear mold core 40 has a second positioning sleeve 41 fixedly connected to it, which engages with the second positioning rod 22. The rear mold core 40 and the front mold core 30 are locked together by a second mold locking buckle 60. The front mold core 30 and the rear mold core 40 are used to injection mold a product 100 with a sprue frame 101. In this embodiment, the product 100 with the sprue frame 101 can be further processed by a stamping process known in the art to separate and obtain the final product 100.

[0029] It should be noted that the quick-change injection mold for optical structural components provided by this invention solves the core problem of balancing mold-changing efficiency and molding quality in optical component production through an innovative split-type and composite locking and positioning design. The main body of the mold consists of an upper mold assembly 10 and a lower mold assembly 20 forming a stable external frame, and the overall locking force and rigidity are ensured by a first locking buckle 50. The core molding parts (front mold core 30 and rear mold core 40) are independent modules, fixed to their respective templates by screws, and locked again at the cavity level by a second locking buckle 60. This structure, which combines the rigidity of the overall frame with the precise locking of the modular cavity, allows the closing accuracy and deformation resistance of the entire mold system to be maintained like a single mold when frequently changing mold cores. This effectively eliminates problems such as flash, dimensional fluctuations, and increased internal stress caused by interface gaps or insufficient rigidity, thereby meeting the stringent requirements of optical structural components for extremely low stress and high dimensional stability.

[0030] Because the mold core, as an independent module, can be quickly assembled and disassembled while maintaining excellent molding performance, it allows for the switching of production of optical components of different models, materials, or colors on the same mold frame, with minimal impact on the optical quality of the final part. Stable locking and precise positioning provide a uniform and stable cavity environment for melt flow during injection molding. Combined with the product 100 design featuring a sprue frame 101, it facilitates balanced filling, further reducing problems such as orientation stress and refractive index unevenness caused by uneven or unstable flow, thereby ensuring the consistency and reliability of key optical properties such as transmittance and refractive index of the optical structural components. Therefore, this invention solves the problem of balancing precision and rigidity in the production of optical structural components using injection molds in the prior art.

[0031] like Figures 1 to 8 As shown, the upper mold assembly 10 is provided with a hot runner structure 13. The end face of the front mold core 30 is provided with a branch channel 32 and a first molding cavity 33, and the end face of the rear mold core 40 is provided with a connected second molding cavity 42 and a third molding cavity 43. The hot runner structure 13 is used to allow fluid to flow to the branch channel 32 so that the fluid fills the first molding cavity 33, the second molding cavity 42 and the third molding cavity 43, and obtains a product 100 with a sprue frame 101. The hot runner structure 13 is provided with a main channel. One end of the branch channel 32 is connected to the main channel, and the other end of the branch channel 32 is connected to the second molding cavity 42. The cross-sectional area of ​​the branch channel 32 gradually decreases along the fluid flow direction. The second molding cavity 42 is used to injection mold the sprue frame 101, and the first molding cavity 33 and the third molding cavity 43 are used to injection mold the product 100.

[0032] In practical implementation, the hot runner structure 13 integrated into the upper mold assembly 10 avoids the generation of solidified material in the main runner, ensuring that the melt enters the distribution system in a constant temperature and homogeneous state. The branch runner 32 adopts a variable cross-section design with a gradually decreasing cross-sectional area along the flow direction. This concept cleverly utilizes the principles of fluid dynamics: the gradually shrinking runner produces a natural aggregation and acceleration effect on the melt, which not only reduces the cooling and hysteresis at the melt front but also effectively reduces the shear stress and pressure fluctuations caused by the abrupt change in the cross-sectional area of ​​the runner. After passing through the optimized branch runner 32, the melt is smoothly and rapidly injected into the second forming cavity 42, and then naturally transitions to the first forming cavity 33 and the third forming cavity 43. This flow sequence of "hot runner → converging branch runner 32 → central gate frame 101 → two product cavities on both sides" constructs a highly symmetrical and resistance-balanced filling network, which greatly ensures that the melt fills the first forming cavity 33 and the third forming cavity 43 synchronously and at equal pressure, laying the foundation for obtaining optical products with consistent molecular orientation and uniform density. The sprue frame 101 serves as a buffer and transition area between the runner and the product 100, which can further release and balance the local concentrated stress from the sprue, and prevent stress from being directly transmitted to the product 100.

[0033] like Figures 7 to 9 As shown, the hot runner structure 13 includes a first runner plate 131 and a first stripper plate 132 respectively fixedly installed in the upper template 11. The upper template 11 is sequentially stacked with a second stripper plate 133 and a second runner plate 134. A runner tube 135 nested with the first stripper plate 132 and the second stripper plate 133 is pressed onto the first runner plate 131. The first ejector plate 132 and the second ejector plate 133 are used for ejecting the sprue from the injection mold. When the injection mold is being molded, the fluid passes sequentially through the second runner plate 134, the runner pipe 135, the first runner plate 131, the front mold core 30, and the rear mold core 40. Specifically, the side of the first runner plate 131 that contacts the first ejector plate 132 is provided with a first hot runner 1311, and the side of the first runner plate 131 that is opposite to the first ejector plate 132 is provided with a discharge port 1312. The discharge port 1312 is connected to the first hot runner 1311 and the branch runner 32, respectively. The runner pipe 135 is provided with a second hot runner 1351, and the second runner plate 134 is provided with a third hot runner 1341. The third hot runner 1341, the second hot runner 1351, and the first hot runner 1311 are connected in sequence to form the main runner.

[0034] In practice, the melt flows sequentially through the third hot runner 1341 in the second runner plate 134, the second hot runner 1351 in the runner tube 135, and the first hot runner 1311 in the first runner plate 131. Then, it enters the branch runner 32 of the mold core through the outlet 1312, and is finally formed in the molding cavities of the front mold core 30 and the rear mold core 40 to obtain the product 100 with the sprue frame 101. This layered and modular runner layout allows each runner section to be independently and precisely temperature-controlled and heat-insulated.

[0035] like Figures 1 to 9 As shown, the upper mold assembly 10 also includes an upper fixing plate 14, a heat insulation plate 15, and a guide post 16. The upper fixing plate 14 is fixedly connected to the second flow channel plate 134. The upper fixing plate 14 is provided with a feed port 141, and a flange 17 is provided at the feed port 141 that is fixedly connected to the upper fixing plate 14. The guide post 16 passes through the second flow channel plate 134, the second stripper plate 133 and the upper template 11 in sequence, and the lower template 21 is equipped with a guide sleeve 211 that is inserted and matched with the guide post 16.

[0036] In practice, since the guide post 16 passes through the second flow channel plate 134, the second ejector plate 133 and the upper mold plate 11 in sequence, and forms a high-precision sliding pair with the guide sleeve 211 on the lower mold plate 21, this long-distance, large-span guiding system, under extremely high clamping force, forces the upper mold assembly 10 and the lower mold assembly 20 to only perform absolutely parallel opening and closing movements along a single axis, eliminating the possibility of lateral offset, torsion or overturning.

[0037] like Figures 2 to 9 As shown, the upper mold plate 11 has a first liquid flow channel 111, the front mold core 30 has a second liquid flow channel 34, the rear mold core 40 has a third liquid flow channel 44, and the lower mold plate 21 has a fourth liquid flow channel 212. The second and third fluid channels 34 are arranged in a crisscross pattern. The first, second, third, and fourth fluid channels 111, 34, 44, and 212 are all used to accommodate and circulate coolant to balance the temperature during injection molding. In this embodiment, a fifth fluid channel 1331 is formed within the second ejector plate 133, and a sixth fluid channel 1342 is formed within the second flow channel plate 134. The first ejector plate 132 has a seventh flow channel 1321. In this embodiment, all the fluid channels are externally connected to the coolant system and penetrate the sidewalls on their opposite sides. Each fluid channel can form a circulating water path or an independent water path. The water path connection of the fluid channels can be designed according to actual working conditions and is not limited here. For example, the first, second, third, fourth, and sixth fluid channels 111, 34, 212, 1331, and 1342 are arranged in the same direction.

[0038] In practical implementation, the design of the first runner 111, the second runner 34, the third runner 44, the fourth runner 212, the fifth runner 1331, and the sixth runner 1342 enables active and precise temperature management of the mold, from the high-temperature runner system to the molding cavity and the external structural frame. The second runner 34 and the third runner 44 are arranged in a cross pattern. This design breaks the limitations of unidirectional water channels and can form a more uniform cooling network inside the mold core. It is particularly beneficial for "point-to-point" efficient heat dissipation in areas with uneven wall thickness of the product 100, minimizing local hot spots and ensuring that all parts of the product 100 cool and solidify uniformly at a near-synchronous rate, thereby significantly reducing uneven shrinkage and internal stress caused by temperature differences. By separately controlling the temperature and flow rate of the coolant flowing through each runner, the system can actively balance the heat impact brought by the periodically injected melt during the injection molding process, enabling the entire mold system (especially the mold core) to quickly reach and maintain a stable thermal equilibrium state.

[0039] like Figure 7 and Figure 8 As shown, a mounting plate 136 nested with the flow channel pipe 135 is fixedly installed inside the second strip plate 133. A hook 137 embedded in the flow channel of the first flow channel plate 131 is installed through the mounting plate 136. The hook 137 is used to prevent the water inlet in the first flow channel plate 131 from falling off.

[0040] In practical implementation, if the sprue sprue at the hot runner outlet unexpectedly falls off, it may cause serious consequences: such as blocking the branch channel 32 on the front mold core 30, resulting in uneven filling; or remaining in the cavity, damaging the next molded product 100. This invention addresses this by fixing a mounting plate 136 on the second ejector plate 133 and providing hooks 137 on the mounting plate 136, allowing the hooks 137 to precisely embed into the first hot runner 1311 of the first runner plate 131. During mold opening, this mechanism reliably hooks the sprue head, ensuring it is carried away from the mold core along with the first ejector plate 132 and the second ejector plate 133, achieving controllable and clean separation of the sprue from the product 100.

[0041] like Figure 3 and Figure 4 As shown, the front mold core 30 has a vent hole 36 and a vent groove 37 that communicate with each other. The vent hole 36 is connected to the second molding cavity 42, and the vent groove 37 is located on the end face of the front mold core 30 opposite to the rear mold core 40. The vent groove 37 communicates with at least one side wall of the front mold core 30. The width of the vent groove 37 is greater than the diameter of the vent hole 36. It is worth mentioning that the vent hole 36 includes a first hole segment and a second hole segment that communicate with each other. The diameter of the first hole segment is greater than the diameter of the second hole segment, and the depth of the first hole segment is less than the depth of the second hole segment. The first hole segment communicates with the second molding cavity 42, and the second hole segment communicates with the vent groove 37.

[0042] In practical implementation, the molding of optical structural components requires the melt front to fill the cavity smoothly and uniformly. If the air or volatile gases trapped in the cavity cannot be discharged in time, it will lead to a sharp increase in pressure at the end of the melt filling and unstable flow, resulting in defects such as gas streaks, scorching (gas being ignited by adiabatic compression), insufficient filling, or local density unevenness. These defects will directly manifest as internal stress concentration points on the surface of product 100. This design provides a preset low-resistance escape path for gas by opening a vent 36 on the front mold core 30 that directly leads to the second molding cavity 42 (sprue frame 101 cavity) and a vent groove 37 that communicates with the vent 36. The width of the vent groove 37 is larger than the diameter of the vent 36, ensuring that the gas can quickly diffuse and be discharged into the atmosphere outside the mold after being discharged from the narrow vent 36, effectively reducing back pressure and ensuring the smooth advancement of the melt front.

[0043] Furthermore, the first orifice section (near the cavity end) has a larger orifice diameter and a shallower depth, designed to provide an initial, rapid venting channel and to initially impede and cool any trace amounts of plastic that may be slightly carried in by the melt front. The second orifice section (far from the cavity end) has a smaller orifice diameter and a greater depth, significantly increasing the pressure and flow resistance required for the melt to pass through this section, forming the main barrier to prevent actual melt overflow (causing flash). Gas molecules can pass freely, but the melt, under the influence of surface tension and rapid cooling, finds it difficult to completely penetrate this long and narrow channel. This stepped structure, characterized by "wide to narrow, short to long," ensures smooth venting while minimizing the risk of melt leakage.

[0044] like Figures 1 to 11 As shown, the lower mold assembly 20 also includes a lower fixing plate 23. Two lower mold partitions 24 are fixedly installed between the lower fixing plate 23 and the lower template 21. One end of the first mold locking buckle 50 is fastened to the lower template 21 by screws, and the other end of the first mold locking buckle 50 is fastened to the second flow channel plate 134 by screws.

[0045] In practice, the lower fixed plate 23 is firmly connected to the moving template of the injection molding machine, providing a precise and reliable installation reference surface for the entire lower mold assembly 20. Two lower mold partitions 24 are fixed between the lower fixed plate 23 and the lower template 21, forming a robust box-type or truss-type support structure. This design greatly enhances the bending stiffness and load-bearing capacity of the lower template 21 in the vertical direction, effectively resisting the enormous cavity pressure during injection molding and preventing the lower template 21 from undergoing slight elastic deformation or deflection under high pressure. The combination of high-rigidity lower mold support and efficient clamping force transmission enables the upper mold assembly 10 and the lower mold assembly 20 to achieve extremely high-precision planar closure under the action of the first clamping buckle 50. This provides a macroscopic absolute clamping guarantee for the precise engagement of the front mold core 30 and the rear mold core 40, eliminating microscopic gaps that may be caused by insufficient rigidity of the template system or poor clamping force transmission.

[0046] like Figure 1 , Figure 2 , Figure 10 and Figure 11 As shown, the lower mold assembly 20 is provided with an ejector assembly 70. The ejector assembly 70 is used to eject the product 100 formed on the front mold core 30 under external lifting force and return it to its initial position under elastic force. The ejector assembly 70 includes a first ejector plate 71 and a second ejector plate 72 stacked in sequence. The first ejector plate 71 is fixedly connected to an ejector rod 73. The second ejector plate 72 is embedded with an ejector pin 74. A return spring 75 is installed between the second ejector plate 72 and the lower mold assembly 20. The first ejector plate 71 and the second ejector plate 72 are both slidably connected within the lower mold assembly 20. A first through hole 47 is provided within the rear mold core 40. One end of the ejector pin 74, relative to the second ejector plate 72, is inserted into the first through hole 47 and abuts against the formed sprue frame 101. In specific implementation, the first ejector plate 71 abuts against the lower fixed plate 23 under the elastic force of the return spring 75.

[0047] In practice, the return spring 75 is installed between the second ejector plate 72 and the lower mold assembly 20, providing a reliable elastic restoring force for the entire ejector assembly 70. Initially, the first ejector plate 71 abuts against the lower fixed plate 23 under the elastic force of the return spring 75, clearly defining the precise mechanical limit point after reset. This ensures that the ejector assembly 70 accurately returns to a defined initial position after each ejection-reset cycle. The ejector assembly 70 is built into a robust lower mold frame composed of the lower fixed plate 23, the lower mold partition 24, and the lower mold plate 21. The force flow path is clear (external lifting force → ejector rod 73 → first ejector plate 71 / second ejector plate 72 → ejector pin 74 → sprue frame 101), and this frame provides rigid guide rail support for ejection sliding. This integrated design makes the mold structure compact with no redundant external parts. The reliable ejection and reset mechanism allows the mold to be put into automated continuous production immediately after the mold core is changed, without the need to worry about additional adjustments required due to the instability of the ejector assembly 70, thus ensuring the high efficiency pursued by quick-change injection molds.

[0048] like Figures 1 to 11 As shown, the side wall of the lower template 21 is provided with a first lifting eye hole 213 for installing a lifting eye, the side wall of the front mold core 30 is provided with a first lifting hole 35, and the side wall of the rear mold core 40 is provided with a second lifting hole 45; both the first lifting hole 35 and the second lifting hole 45 are used to attach lifting bolts when replacing the front mold core 30 and the rear mold core 40. In this embodiment, the side wall of the upper template 11 is provided with a second lifting eye hole 112 for installing a lifting eye.

[0049] In practice, by independently setting a first lifting hole 35 and a second lifting hole 45 on the side walls of the front mold core 30 and the rear mold core 40 respectively, a dedicated standard force point is provided for each mold core. During operation, the lifting bolts are directly attached to these lifting holes, allowing the line of action of the lifting force to pass directly through the mold core body, ensuring a smooth lifting process. Since the first lifting eye hole 213 is used for the overall lifting of the lower mold assembly 20, and the second lifting eye hole is used for the overall lifting of the upper mold assembly 10; while the independent lifting holes on the mold cores are dedicated to the assembly and disassembly of the mold cores; this clearly defined multi-level lifting design standardizes the mold changing process: operators can follow fixed steps, first lifting the old mold core as a whole, and then precisely lifting the new mold core into place. The dedicated lifting hole design makes the lifting tool connection quick and reliable, significantly reducing preparation and adjustment time. like Figure 3 and Figure 4 As shown, the front mold core 30 is fixedly installed with two diagonally distributed third positioning rods 38, and the rear mold core 40 is fixedly installed with two diagonally distributed third positioning sleeves 46. The third positioning rods 38 and the third positioning sleeves 46 are inserted into each other in a one-to-one correspondence. Among them, two third positioning rods 38 and two first positioning sleeves 31 are staggered at the four corners of the front mold core 30, and two third positioning sleeves 46 and two second positioning sleeves 41 are staggered at the four corners of the rear mold core 40.

[0050] In practical implementation, two diagonally distributed third positioning rods 38 are fixed to the front mold core 30, and two corresponding third positioning sleeves 46 are fixed to the rear mold core 40. When the front mold core 30 and the rear mold core 40 are closed within the mold frame, they are simultaneously constrained by two sets of orthogonal positioning forces: one set is transmitted through the template to ensure the position of the mold core within the template; the other set is directly engaged between the mold cores to ensure the relative position of the cavities of the front mold core 30 and the rear mold core 40. This dual guarantee of "template positioning" and "mold core mutual positioning" constructs a redundant and three-dimensional precision positioning system, ensuring absolute accuracy and repeatability of mold closing. Through the insertion and engagement of the third positioning rods 38 and the third positioning sleeves 46, a robust mechanical interlock is formed after mold closing; it not only serves a positioning function but also acts as an additional support column, effectively distributing and resisting the enormous cavity pressure during injection molding, especially the off-center load brought by the asymmetrical product 100. This design significantly improves the overall rigidity of the mold core itself, reduces the risk of elastic deformation of the mold core under high pressure, and further ensures dimensional stability. At the same time, the uniform force distribution reduces stress concentration, protects the precision positioning sleeve and molding surface, and helps maintain the long-term accuracy and lifespan of the mold.

[0051] Working Principle: This invention provides a quick-change injection mold for optical structural components. Through an innovative split-type and composite locking and positioning design, it solves the core problem of balancing mold-changing efficiency and molding quality in optical component production. The main body of the mold consists of an upper mold assembly 10 and a lower mold assembly 20 forming a stable external frame, and the overall clamping force and rigidity are ensured by a first clamping buckle 50. The core molding parts (front mold core 30 and rear mold core 40) are independent modules, fixed to their respective templates by screws, and further locked at the cavity level by a second clamping buckle 60. This structure, which combines the rigidity of the overall frame with the precise locking of the modular cavity, allows the closure accuracy and deformation resistance of the entire mold system to be maintained like a single mold when frequently changing mold cores. This effectively eliminates problems such as flash, dimensional fluctuations, and increased internal stress caused by interface gaps or insufficient rigidity, thereby meeting the stringent requirements of optical structural components for extremely low stress and high dimensional stability.

[0052] Because the mold core, as an independent module, can be quickly assembled and disassembled while maintaining excellent molding performance, it allows for the switching of production of optical components of different models, materials, or colors on the same mold frame, with minimal impact on the optical quality of the final part. Stable locking and precise positioning provide a uniform and stable cavity environment for melt flow during injection molding. Combined with the product 100 design featuring a sprue frame 101, it facilitates balanced filling, further reducing problems such as orientation stress and refractive index unevenness caused by uneven or unstable flow, thereby ensuring the consistency and reliability of key optical properties such as transmittance and refractive index of the optical structural components. Therefore, this invention solves the problem of balancing precision and rigidity in the production of optical structural components using injection molds in the prior art.

[0053] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A quick-change injection mold for optical structural components, characterized in that, It includes an upper mold assembly (10), a lower mold assembly (20), a front mold core (30), and a rear mold core (40). The upper mold assembly (10) and the lower mold assembly (20) are locked together by a first mold locking buckle (50). The upper mold assembly (10) includes an upper template (11), and at least two first positioning rods (12) are installed on the upper template (11) in a diagonal arrangement. The lower mold assembly (20) includes a lower template (21), on which at least two second positioning rods (22) are installed in a diagonal arrangement, and the second positioning rods (22) correspond one-to-one with the first positioning rods (12); The front mold core (30) is fixedly connected to a first positioning sleeve (31) that is inserted into the first positioning rod (12), and the rear mold core (40) is fixedly connected to a second positioning sleeve (41) that is inserted into the second positioning rod (22). The rear mold core (40) and the front mold core (30) are locked together by a second mold locking buckle (60). The front mold core (30) and the rear mold core (40) are used to injection mold a product (100) with a sprue frame (101).

2. The quick-change injection mold for optical structural components according to claim 1, characterized in that, The upper mold assembly (10) is provided with a hot runner structure (13). The end face of the front mold core (30) is provided with a branch channel (32) and a first molding cavity (33). The end face of the rear mold core (40) is provided with a second molding cavity (42) and a third molding cavity (43) that are connected. The hot runner structure (13) is used to allow fluid to flow to the branch channel (32) so that the fluid fills the first molding cavity (33), the second molding cavity (42) and the third molding cavity (43) to obtain a product (100) with a sprue frame (101).

3. The quick-change injection mold for optical structural components according to claim 2, characterized in that, The hot runner structure (13) has a main channel, one end of the branch channel (32) is connected to the main channel, and the other end of the branch channel (32) is connected to the second molding cavity (42). The cross-sectional area of ​​the branch channel (32) gradually decreases along the fluid flow direction. The second molding cavity (42) is used to injection mold a sprue frame (101), and the first molding cavity (33) and the third molding cavity (43) are used to injection mold a product (100).

4. The quick-change injection mold for optical structural components according to claim 3, characterized in that, The hot runner structure (13) includes a first runner plate (131) and a first stripper plate (132) respectively fixedly installed in the upper template (11). The upper template (11) is stacked with a second stripper plate (133) and a second runner plate (134). The first runner plate (131) is pressed with a runner tube (135) nested with the first stripper plate (132) and the second stripper plate (133) respectively. The first ejector plate (132) and the second ejector plate (133) are used for ejecting the sprue of the injection mold. When the injection mold is being injection molded, the fluid passes through the second runner plate (134), the runner pipe (135), the first runner plate (131), the front mold core (30), and the rear mold core (40) in sequence.

5. The quick-change injection mold for optical structural components according to claim 4, characterized in that, The upper mold assembly (10) also includes an upper fixing plate (14), a heat insulation plate (15), and a guide post (16). The upper fixing plate (14) is fixedly connected to the second flow channel plate (134). The upper fixing plate (14) is provided with a feed port (141), and a flange (17) is provided at the feed port (141) and fixedly connected to the upper fixing plate (14). The guide post (16) passes through the second flow channel plate (134), the second stripper plate (133) and the upper template (11) in sequence, and the lower template (21) is equipped with a guide sleeve (211) that is inserted and matched with the guide post (16).

6. The quick-change injection mold for optical structural components according to claim 2 or 4, characterized in that, The upper mold plate (11) has a first liquid flow channel (111), the front mold core (30) has a second liquid flow channel (34), the rear mold core (40) has a third liquid flow channel (44), and the lower mold plate (21) has a fourth liquid flow channel (212). The second liquid flow channel (34) and the third liquid flow channel (44) are arranged in a cross pattern. The first liquid flow channel (111), the second liquid flow channel (34), the third liquid flow channel (44) and the fourth liquid flow channel (212) are all used to contain coolant for circulation in order to balance the temperature of the injection mold during injection molding.

7. The quick-change injection mold for optical structural components according to claim 4, characterized in that, The second stripper plate (133) is fixedly installed with a mounting plate (136) nested with the flow channel pipe (135). The mounting plate (136) is provided with a hook (137) embedded in the flow channel of the first flow channel plate (131). The hook (137) is used to prevent the water outlet in the first flow channel plate (131) from falling off.

8. The quick-change injection mold for optical structural components according to any one of claims 2 to 5, characterized in that, The front mold core (30) has an interconnected vent hole (36) and vent groove (37). The vent hole (36) is connected to the second molding cavity (42). The vent groove (37) is located on the end face of the front mold core (30) facing away from the rear mold core (40). The vent groove (37) is connected to at least one side wall of the front mold core (30). The width of the vent groove (37) is greater than the diameter of the vent hole (36).

9. The quick-change injection mold for optical structural components according to claim 1, characterized in that, The lower mold assembly (20) is provided with an ejector assembly (70), which is used to eject the product (100) formed on the front mold core (30) under external lifting force and return it to the initial position under elastic force.

10. The quick-change injection mold for optical structural components according to claim 9, characterized in that, The top material assembly (70) includes a first top material plate (71) and a second top material plate (72) stacked in sequence. The first top material plate (71) is fixedly connected to a top rod (73). The second top material plate (72) is embedded with a top pin (74). A return spring (75) is installed between the second top material plate (72) and the lower mold assembly (20). The first ejector plate (71) and the second ejector plate (72) are slidably connected in the lower mold assembly (20). The rear mold core (40) is provided with a first through hole (47). One end of the ejector pin (74) relative to the second ejector plate (72) is inserted into the first through hole (47) and abuts against the formed sprue frame (101).

11. The quick-change injection mold for optical structural components according to claim 1, characterized in that, The lower template (21) has a first lifting eye hole (213) on its side wall for installing lifting eye, the front mold core (30) has a first lifting hole (35) on its side wall, and the rear mold core (40) has a second lifting hole (45) on its side wall; the first lifting hole (35) and the second lifting hole (45) are both used to hang the lifting bolts when replacing the front mold core (30) and the rear mold core (40).

12. The quick-change injection mold for optical structural components according to claim 1 or 11, characterized in that, The front mold core (30) is fixedly installed with two third positioning rods (38) arranged diagonally, and the rear mold core (40) is fixedly installed with two third positioning sleeves (46) arranged diagonally. The third positioning rods (38) and the third positioning sleeves (46) are inserted into each other in a one-to-one correspondence. Among them, the two third positioning rods (38) and the two first positioning sleeves (31) are staggered at the four corners of the front mold core (30), and the two third positioning sleeves (46) and the two second positioning sleeves (41) are staggered at the four corners of the rear mold core (40).

13. The quick-change injection mold for optical structural components according to claim 1, characterized in that, The lower mold assembly (20) also includes a lower fixing plate (23), and two lower mold partitions (24) are fixedly installed between the lower fixing plate (23) and the lower template (21). One end of the first locking buckle (50) is fastened to the lower template (21) by screws.

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