Injection mold and injection process for a progressive multi-focal lens

Abstract

The application relates to the technical field of injection molding processing, and particularly discloses an injection mold for a progressive multifocal lens and an injection molding process thereof, wherein the mold comprises a movable mold and a fixed mold which are oppositely arranged from top to bottom; the top of the fixed mold is provided with a fixed mold cavity; a forming table is arranged inside and below the fixed mold cavity; a forming cavity is arranged in the middle of the top of the forming table; the bottom of the movable mold is provided with a movable mold table which extends into the fixed mold cavity; the bottom of the movable mold table is provided with a shaping die plate which is matched with the forming cavity; after the movable mold and the fixed mold are moved close to each other, an injection mold cavity for lens forming is formed through the shaping die plate and the forming cavity; a deformable die plate corresponding to the progressive light ray surface of the lens is arranged at the bottom of the forming cavity; a temperature control assembly is arranged in the deformable die plate; the temperature change is controlled through the temperature control assembly to realize the accurate adjustment of the curvature of the deformable die plate; the temperature step adjustment of each curved surface section and the accurate curvature adaptation are realized, and the optical precision of the lens after injection molding is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of injection molding, and discloses an injection mold for progressive multi-focal lenses and an injection molding process thereof. BACKGROUND

[0002] In the current injection molding production of progressive multi-focal lenses, the injection mold and process adopted by the mainstream of the prior art have formed a relatively fixed technical system: the mold structure is mainly composed of a movable mold and a fixed mold, so that the mold cavity is formed after the two molds are closed; in the injection molding process, the steps of "preheating the mold, closing and locking the mold, injecting the molten resin, pressure maintaining and cooling, and opening the mold to take out the product" are generally followed; the resin is delivered to the straight gate or ordinary side gate (usually arranged at the center or on one side of the mold plate) on the mold plate through the injection runner in the movable mold; the excess gas in the mold cavity is discharged through the independent exhaust groove or small exhaust valve at the parting surface; the temperature of the mold plate is maintained through the integral temperature control runner (which uniformly controls the temperature of the entire mold plate); and the resin debris remaining on the surface of the molded lens needs to be cleaned by subsequent manual wiping or independent blowing device (which is not linked with the mold opening and closing action).

[0003] However, the prior art has many defects in practical application and cannot meet the high-precision production requirements of progressive multi-focal lenses: first, the precision of curved surface forming is insufficient, because the far use area, transition area and near use area of the progressive multi-focal lens need to present continuous decreasing curvature changes, the fixed curved surface structure of the forming cavity and the mold plate cannot be adjusted according to the dynamic changes of the resin flow and cooling shrinkage, the integral temperature control easily leads to local temperature fluctuations, causing unexpected deformation of the mold plate, which reduces the optical precision of the lens and affects the visual effect; second, the exhaust and cleaning efficiency is low, the independent exhaust groove has limited exhaust capacity, and the residual bubbles during mold closing may damage the light transmittance of the lens, and the independent blowing device needs to be started additionally, which not only increases the time consumption, but also may cause incomplete cleaning due to the close adhesion of debris, and manual cleaning may scratch the optical surface and reduce the yield of finished products.

[0004] Therefore, it is urgent for the industry to provide an injection mold for progressive multi-focal lenses and an injection molding process thereof. SUMMARY

[0005] The present application aims to provide an injection mold for progressive multi-focal lenses and an injection molding process thereof, which at least solves one of the above technical problems in the prior art.

[0006] Specifically, the present application is realized by the following technical scheme:

[0007] The injection mold of the progressive multifocal lens comprises a movable mold and a fixed mold arranged oppositely from top to bottom, the top of the fixed mold is provided with a fixed mold cavity, a forming table is arranged inside and below the fixed mold cavity, the top of the forming table is provided with a forming cavity, the bottom of the movable mold is provided with a movable mold table extending into the fixed mold cavity, the bottom of the movable mold table is provided with a shaping template matched with the forming cavity, and the shaping template and the forming cavity form an injection mold cavity for lens forming when the movable mold and the fixed mold are closed to each other.

[0008] A deformable template matched with the progressive light ray surface of the lens is arranged at the bottom of the forming cavity, a temperature control assembly is arranged inside the deformable template, and the temperature change is controlled by the temperature control assembly to realize the accurate adjustment of the curvature of the deformable template.

[0009] An air flow cleaning mechanism is further arranged in the fixed mold cavity, and the air flow cleaning mechanism blows the outer optical surface of the lens during the opening of the movable mold.

[0010] The technical scheme is characterized in that a deformable template matched with the progressive light ray surface of the lens is arranged at the bottom of the forming cavity, and a temperature control assembly is arranged inside the deformable template, and the temperature change is accurately controlled by the temperature control assembly (for example, different temperature signals are transmitted to the corresponding areas of the deformable template according to the continuous decreasing curvature requirements of the distance area, the transition area and the near area of the lens, and the temperature change drives the material of the deformable template to produce controllable deformation), so as to replace the existing fixed curved surface structure which cannot be finely adjusted and the overall temperature control which is prone to local fluctuations, so that the curved surface of the deformable template can adapt to the shape change of the resin during the flowing, cooling and shrinking processes in real time, the unexpected deformation of the template is avoided, the lens is accurately matched with the curved surface in each area, the optical precision is significantly improved, and the viewing effect is improved. Secondly, the air flow cleaning mechanism is arranged in the fixed mold cavity, and the mechanism does not need to be started independently, but is linked with the opening of the movable mold, and directly blows the outer optical surface of the lens during the opening of the movable mold. The physical action of the air flow efficiently removes the residual resin debris, avoids the damage to the optical surface caused by manual cleaning, saves the additional operation steps of the independent air blowing device, and greatly improves the cleaning efficiency and the yield of finished products.

[0011] Optionally, an injection flow channel is arranged inside the movable mold, the bottom of the injection flow channel is in communication with the injection gate on the shaping template, the injection gates are symmetrically arranged on both sides of the bottom of the shaping template and are inclined in directions away from each other, and the inner diameter of the injection gate gradually decreases along the flow direction of the pouring medium.

[0012] Optionally, the top of the deformable template is inwardly recessed and forms a deformable curved surface matched with the progressive light ray surface of the lens, and the deformable curved surface comprises a first deformation curved surface segment, a second deformation curved surface segment and a third deformation curved surface segment with gradually decreasing and smoothly transitioned curvature radii.

[0013] Optionally, the temperature control assembly is embedded in the bottom of the first, second and third deformed curved surface segments, respectively, and the temperature step change of each deformed curved surface segment is adjusted by the temperature control assembly to correspondingly adjust the radius of curvature of the first, second and third deformed curved surface segments to adapt to the progressive light ray surface of the lens.

[0014] The temperature control assembly comprises a heat conduction cavity, which is connected to the outside through a heat conduction pipeline. A heat conduction plate is attached to the inside of the heat conduction cavity. The heat conduction plate has heat conduction micro-holes inside. The heat conduction micro-holes are three-dimensional intercommunicating hole arrays and form a grid-like structure with spatial intersections.

[0015] Optionally, a pushing mechanism is further arranged between the movable mold and the fixed mold. The pushing mechanism is used to push the movable mold to reciprocate on the fixed mold to perform the mold opening and closing action. The pushing mechanism comprises a gas cylinder and a guide assembly. The gas cylinder is symmetrically arranged on both sides of the fixed mold table, and the output end thereof is vertically upward and connected with the movable mold table. The guide assembly is symmetrically arranged on both sides of the inside of the fixed mold cavity, and the guide assembly comprises a guide column with a top end recessed inward to form an accommodating cavity, a guide sliding rod slidingly arranged in the accommodating cavity of the guide column and extending to the outside of the accommodating cavity with the top end connected with the movable mold table.

[0016] Further optionally, the air flow cleaning mechanism comprises a gas storage cylinder arranged in the accommodating cavity of the guide column. A piston push plate is slidingly arranged in the gas storage cylinder and sealingly matched with the gas storage cylinder. A gas storage area is formed between the upper part of the piston push plate and the gas storage cylinder. The upper part of the piston push plate is provided with a connecting rod penetrating to the outside of the gas storage cylinder. The connecting rod is slidingly sealed with the gas storage cylinder, and the top end thereof is connected with the bottom end of the guide sliding rod. A micro-slit nozzle is further arranged at a position corresponding to the lens progressive light ray surface on the side of the molding cavity. The micro-slit nozzle is connected with the gas storage area through an air flow pipeline.

[0017] Optionally, the shape of the micro-slit nozzle is a narrow slit, and the outlet end thereof is further provided with an anti-spilling plug made of high-temperature-resistant silicone rubber.

[0018] Optionally, an ejection mechanism is further arranged on the movable mold. The ejection mechanism comprises an ejection cavity symmetrically arranged in the inside of the movable mold table and close to the position of the injection gate. The bottom of the ejection cavity penetrates the shaping mold plate, and an ejector pin table is slidingly matched in the inside of the ejection cavity. The ejector pin table is sealingly matched with the bottom opening of the ejection cavity, and an ejection oil cylinder is connected to the upper part of the ejector pin table.

[0019] Further, the present scheme proposes an injection molding process for progressive multi-focal lenses. Based on an injection mold for progressive multi-focal lenses, the process comprises the following steps:

[0020] Pre-injection, preheat the temperature control assembly of the deformable template to adjust the initial temperature of the first, second and third deformation curved sections, so that the deformable curved surface maintains the initial fitting accuracy with the lens progressive light curve, and at the same time, prepare the molten lens resin for use;

[0021] Mold closing and cavity exhaust, start the cylinder of the pushing mechanism, make its output end contract and drive the movable mold to move downward and close to the fixed mold. During this process, the anti-overflow plug is not completely compressed, and the outlet end of the micro-gap nozzle is in a conductive state. The guide slide rod moves downward with the movable mold platform along the containing cavity of the guide column. Through the connecting rod, the piston push plate is synchronously pushed to move downward along the gas reservoir, so that the volume of the gas storage area increases to form negative pressure. The negative pressure extracts the excess gas in the molding cavity through the micro-gap nozzle, avoiding the generation of bubbles in the subsequent injection. As the movable mold continues to close to the fixed mold, the shaping template gradually extends into the molding cavity. As the shaping template gradually extrudes, the anti-overflow plug is compressed and completely closed under pressure until the movable mold and the fixed mold are completely closed. At this time, the shaping template and the deformable template are closed to form an injection mold cavity.

[0022] Injection molding, the molten lens resin is delivered to the injection sprue of the shaping template through the injection runner of the movable mold, and uniformly flows into the injection mold cavity through the injection sprue until it is filled. During the injection process, the temperature control assembly controls the temperature control medium to be introduced into the heat conduction cavity through the heat conduction pipeline, so as to adjust the radius of curvature of the deformable curved surface through temperature step change, so as to make it real-time adapt to the curved surface accuracy of the lens progressive light curve.

[0023] Pressure holding and curing, maintain the initial pressure of the movable mold and the fixed mold to keep the pressure, so as to compensate for the shrinkage of the resin during cooling, while maintaining the temperature stability of the temperature control assembly to avoid unintended curvature changes of the deformable curved surface due to temperature fluctuations. Through the heat conduction micro-pores of the heat conduction plate, the resin in the injection mold cavity is slowly cooled to the temperature required for solidification along the shape of the deformable curved surface, ensuring that the resin always adheres to the deformable curved surface during the solidification process, avoiding optical precision deviation of the lens caused by curved surface deformation, until the resin is completely solidified.

[0024] Mold opening and air flow purging, start the cylinder of the pushing mechanism again, make it drive the movable mold to move upward to gradually move away from the fixed mold for mold opening action. At this time, the guide slide rod in the guide column moves upward and drives the piston push plate to compress the gas storage area through the connecting rod, gradually forming high-pressure gas flow into the pipeline, and then opening the anti-overflow plug through the high-pressure gas flow, so that the high-pressure gas in the gas storage area continuously blows the outer optical surface of the lens through the micro-gap nozzle to remove surface debris.

[0025] Ejection and part taking, start the ejection cylinder of the ejection mechanism to drive the ejector platform to move downward along the ejection cavity. The ejector platform passes through the shaping template to eject the lens. After the lens is taken out, the ejector platform is controlled to reset, completing a single injection work.

[0026] The injection molding process provided by the scheme realizes dynamic control of the forming precision of the curved surface of the progressive multi-focal lens, solves the curvature deviation problem caused by the fixed structure, improves the gas exhaust efficiency and surface cleanliness through the linkage design of mold closing and exhaust and mold opening and cleaning, and effectively suppresses the influence of temperature fluctuation on the curved surface precision through the cooperation of the regional temperature control and the heat conduction structure, so that the optical performance of the lens meets the design requirements.

[0027] Compared with the prior art, the present application has at least the following advantages and beneficial effects:

[0028] (1) By setting the deformable mold plate containing the first, second and third deformation curved surface segments at the bottom of the forming cavity, and matching the temperature control components embedded at the bottom of each curved surface segment, the temperature step adjustment and curvature precise adaptation of each curved surface segment are realized, the problems of unable to fine-tune and easy to deform of the overall temperature control of the existing fixed curved surface are solved, and thus the optical precision of the lens after injection molding is greatly improved.

[0029] (2) The present application cleverly links the guide slide rod and connecting rod of the airflow cleaning mechanism and the pushing mechanism, uses the negative pressure formed during mold closing to exhaust the gas in the forming cavity, uses the high-pressure airflow generated during mold opening to blow the lens, cooperates with the anti-glue overflow plug of the micro-gap nozzle, avoids bubble residue and scratch caused by debris, improves the yield of the finished product after the injection mold, and improves the use effect.

[0030] (3) The present application sets the pushing mechanism composed of symmetrical air cylinders and guide components, and the ejection mechanism near the injection gate, to ensure smooth and precise mold opening and closing, avoid damage to the optical surface of the lens during ejection, ensure production stability, and improve the production precision of the injection mold.

[0031] (4) The injection molding process and mold structure of the present application are deeply coordinated, the dynamic control of the forming precision of the curved surface of the progressive multi-focal lens is realized, the curvature deviation problem caused by the fixed structure is solved, the linkage design of mold closing and exhaust and mold opening and cleaning is used to improve the gas exhaust efficiency and surface cleanliness, and the cooperation of the regional temperature control and the heat conduction structure effectively suppresses the influence of temperature fluctuation on the curved surface precision, thereby ensuring that the optical performance of the lens meets the design requirements and improving the injection molding production efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0032] The drawings described herein are used to provide further understanding of the embodiments of the present application, constitute a part of the present application, and do not constitute a limitation on the embodiments of the present application. In the drawings:

[0033] Figure 1 It is a schematic diagram of the overall structure of the injection mold of the present application;

[0034] Figure 2 It is a schematic diagram of the internal heat conduction micropore structure of the heat conduction plate of the present application;

[0035] Figure 3 A partial enlarged structural schematic view of the guide assembly and the airflow cleaning mechanism of the present application;

[0036] Figure 4 A partial enlarged structural schematic view of the guide assembly and the airflow cleaning mechanism of the present application; Figure 3

[0037] Figure 5 A partial structural schematic view of the ejection mechanism of the present application;

[0038] Figure 6 A partial structural schematic view of the ejection mechanism of the present application; Figure 5

[0039] Figure 7 A schematic view of the injection molding process steps of the present application.

[0040] In the above-mentioned drawings, the reference signs represent: 1, moving mold; 11, moving mold base; 12, fixed mold plate; 13, injection runner; 131, injection gate; 2, fixed mold; 21, fixed mold cavity; 22, forming base; 23, forming cavity; 231, deformable mold plate; 2311, deformable curved surface; 2312, heat conduction plate; 2313, heat conduction micro-holes; 2411, air cylinder; 2412, piston push plate; 2413, air storage area; 2414, air flow pipeline; 2415, micro-slit nozzle; 25, ejection mechanism; 251, ejection cavity; 252, ejector pin base; 253, ejection oil cylinder; 26, trimming cutter; 261, sliding slot; 262, horizontal cavity; 263, wedge block; 3, injection mold cavity; 41, air cylinder; 42, guide assembly; 421, guide column; 422, guide slide bar. DETAILED DESCRIPTION

[0041] In order to make the objectives, technical solutions and advantages of the present application clearer, further detailed description will be made to the present application in combination with embodiments, the illustrative embodiments and the description thereof are only used to explain the present application, and cannot be used as limitation to the present application, the embodiments described below are part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0042] In addition, the terms “first” and “second” are only used for description purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by “first” and “second” can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of “multiple” is two or more, unless otherwise specifically limited.

[0043] ​​It should be understood that the progressive multi-focal lens as an optical component is the prior art, and the lens progressive light curve refers to the optical curve surface that matches the functional requirements of the three regions and the curvature changes continuously. Through the curve surface, the refraction angles of light in different regions can be adapted to the corresponding visual scenes to realize seamless switching of "far, middle and near" vision. In this application, it is the curve surface on the side of the progressive multi-focal lens towards the forming cavity.

[0044] Embodiment 1:

[0045] Please refer to Figure 1 The embodiment discloses an injection mold for a progressive multi-focal lens, which comprises a movable mold 1 and a fixed mold 2 arranged opposite from top to bottom. The top of the fixed mold 2 is provided with a fixed mold cavity 21. A forming table 22 is arranged inside and below the fixed mold cavity 21. The top middle of the forming table 22 is provided with a forming cavity 23. The bottom of the movable mold 1 is provided with a movable mold table 11 extending into the fixed mold cavity 21. The bottom of the movable mold table 11 is provided with a shaping mold plate 12 matched with the forming cavity 23. After the movable mold 1 and the fixed mold 2 are closed, the shaping mold plate 12 and the forming cavity 23 form an injection mold cavity 3 for lens forming.

[0046] A deformable mold plate 231 corresponding to the lens progressive light curve is arranged at the bottom of the forming cavity 23. A temperature control assembly is arranged inside the deformable mold plate 231. The temperature control assembly controls the temperature change to accurately adjust the curvature of the deformable mold plate 231.

[0047] An air flow cleaning mechanism is further arranged in the fixed mold cavity 21. The air flow cleaning mechanism blows air to the outer optical surface of the lens during the opening of the movable mold 1.

[0048] It should be noted that in the prior art, the progressive multi-focal lens injection mold generally adopts a fixed curve forming structure. After the movable mold 1 and the fixed mold 2 are closed, a static mold cavity is formed, which cannot adapt to the curvature change caused by resin cooling and shrinkage. The traditional mold relies on an overall temperature control system to adjust the temperature of the mold plate, which causes uneven distribution of local thermal stress and affects the optical precision of the lens. The mold cavity exhaust relies on a parting surface exhaust groove or an independent exhaust valve. Gas residues are easy to form bubbles. After opening, the lens surface debris needs to be cleaned manually or by independent equipment, which has the risk of low cleaning efficiency and damage to the optical surface.

[0049] Therefore, through further analysis, it is found that the key to the problem of the existing fixed curved surface structure cannot dynamically compensate for the resin shrinkage deformation, leading to curvature deviation in each area of the lens, lies in how to achieve dynamic adjustment of the forming curved surface. In addition, for the problem of gas residue in the mold cavity and low surface cleaning efficiency, the key lies in how to link the mold cavity exhaust action with the mold opening and closing power to strengthen the exhaust thoroughness, while realizing the synergy of surface cleaning and mold opening process, ensuring cleaning effect while avoiding the risk of optical surface damage.

[0050] That is, based on the above analysis, the present embodiment sets a deformable mold plate 231 at the bottom of the forming cavity 23, which is adapted to the progressive light ray curved surface of the lens, and configures a temperature control component inside it. During work, the temperature change is accurately controlled by the temperature control component (such as transmitting different temperature signals to the corresponding area of the deformable mold plate 231 according to the continuous decreasing curvature requirements of the far vision area, transition area and near vision area of the lens, and using temperature change to drive the material of the deformable mold plate 231 to produce controllable deformation), to replace the existing fixed curved surface structure which cannot be finely adjusted and the overall temperature control which is prone to local fluctuations, so that the curved surface of the deformable mold plate 231 can adapt to the shape change of the resin during the flow and cooling shrinkage process in real time, avoid unexpected deformation of the mold plate, ensure the precise fit of each area of the lens with the curved surface, significantly improve the optical precision to improve the visual effect. Secondly, the present scheme sets an airflow cleaning mechanism in the fixed mold cavity 21, and this mechanism does not need to start an independent process, but is linked with the mold opening action of the movable mold 1. During the mold opening process of the movable mold 1, the outer optical surface of the lens is directly blown by airflow, which efficiently removes the residual resin debris through the physical action of airflow, avoiding the damage to the optical surface caused by manual cleaning, and saving the additional operation steps of independent air blowing device, greatly improving the cleaning efficiency and product yield.

[0051] For the deformable template 231, it is preferably made of a nickel-titanium memory alloy plate or a modified heat-sensitive polymer composite material (such as a carbon fiber reinforced polyether ether ketone (PEEK) based composite material), which has excellent heat response sensitivity and shape memory stability, and can meet the precise adjustment requirements of the progressive curvature of the lens. For example, the thermal deformation principle of the nickel-titanium memory alloy material is based on the martensite-austenite phase change effect. It needs to be further supplemented that the deformable template 231 based on the martensite-austenite phase change effect is not a theoretical concept, and its application in the fields of medical treatment, aerospace, precision machinery, etc. is already relatively wide. For example, in the medical field, in addition to being used for dental correction wires and orthopedic fixation devices, the most typical one is the vascular stent product. Such a nickel-titanium memory alloy vascular stent is pre-set with a net-shaped support shape after expansion (corresponding to the pre-set curvature shape of the deformable template 231) during production. It can be compressed into a thin tubular shape with a diameter of only a few millimeters (similar to the basic shape of the deformable template 231 in the initial state) in a low-temperature environment, so as to be conveniently implanted into a blood vessel stenosis site through a catheter. After implantation, the stent contacts the body temperature (corresponding to the heating of the temperature control component of the deformable template 231), which will quickly trigger the phase change from martensite to austenite, automatically restore to the pre-set net-shaped expansion shape, and tightly fit the blood vessel wall to achieve the support function. Its application logic is similar to that of the deformable template 231. Both of them rely on the characteristics of the nickel-titanium memory alloy "temperature-driven shape change", and through external temperature precise control (the vascular stent relies on the body temperature, and the deformable template 231 relies on the temperature control component), the material realizes the precise presentation of the pre-set shape in a specific scene. Moreover, the phase change temperature control precision and shape recovery stability of this technology have met the industrial mass production requirements through years of engineering verification, and can provide reliable technical support for the dynamic adjustment of the curvature during the molding of the progressive multi-focal lens.

[0052] In addition, for the present application, although it is based on the existing mature nickel-titanium memory alloy phase change technology, it is not a simple application of this technology, but a unique technical solution formed for the unique technical pain points of the injection molding of the progressive multi-focal lens. That is, the present application ingeniously introduces this material into the deformable template 231 of the progressive multi-focal lens mold, which not only adapts to the continuous curvature change of the far use area, the transition area and the near use area of the lens, but also simultaneously solves the technical difficulty of real-time compensation for resin cooling shrinkage, which is a unique technical difficulty in the mold field. The present application precisely controls the temperature gradient of different regions through the temperature control component, so that the deformable template 231 occurs step by step and in zones according to the curvature requirements of the injection molded lens, realizes the continuous progressive adjustment of the progressive optical surface, and combines with the shrinkage characteristics of the lens resin to make the deformable template 231 dynamically match the resin shrinkage. It is a technical adaptation and improvement for the lens injection molding scene, and solves the technical problems of the traditional fixed curved surface mold, such as the inability to compensate for resin shrinkage and low optical precision.

[0053] In some optional embodiments, in Figure 1It has been shown that the inside of the movable mold 1 is provided with an injection flow channel 13, the bottom of the injection flow channel 13 is connected with the injection gate 131 on the shaping mold plate 12, the injection gate 131 is symmetrically arranged on both sides of the bottom of the shaping mold plate 12 and is inclinedly arranged in the direction away from each other, and the inner diameter of the injection gate 131 gradually decreases along the flow direction of the pouring medium.

[0054] The embodiment designs the symmetrically distributed inclined gate to make the resin form a symmetric flow pattern in the mold cavity, effectively eliminates the thickness difference caused by one-sided filling, and the taper gate adopted by the scheme can dynamically adjust the flow rate, which can ensure rapid filling and avoid air bubble defects caused by turbulent flow.

[0055] In some optional embodiments, the top of the deformable mold plate 231 is recessed inward and forms a deformable curved surface 2311 adapted to the progressive light ray curved surface of the lens, the deformable curved surface 2311 includes a first deformation curved surface segment, a second deformation curved surface segment and a third deformation curved surface segment with gradually decreasing curvature radii and smooth transition.

[0056] The top recessed structure of the deformable mold plate 231 is divided into three continuous curved surface segments in the embodiment, the three curved surface segments are connected through smooth transition curves, which ensures the continuity of the curvature change during the resin forming process, thereby realizing the differential deformation control of different optical regions.

[0057] As a preferred embodiment, please refer to Figure 1 and Figure 2 , the temperature control assembly is embedded in the bottom of the first deformation curved surface segment, the second deformation curved surface segment and the third deformation curved surface segment respectively, and the temperature step change of each deformation curved surface segment is adjusted through the temperature control assembly to correspondingly adjust the curvature radii of the first deformation curved surface segment, the second deformation curved surface segment and the third deformation curved surface segment, so that they are adapted to the progressive light ray curved surface of the lens;

[0058] The temperature control assembly includes a heat conduction cavity, the heat conduction cavity is connected with the outside through a heat conduction pipeline, a heat conduction plate 2312 is attached inside the heat conduction cavity, a heat conduction micro-hole 2313 is formed in the heat conduction plate 2312, and the heat conduction micro-hole 2313 is a three-dimensional intercommunicating hole array and forms a grid-like structure with spatial intersection.

[0059] It should be understood that the three-dimensional intercommunicating hole array of the heat conduction micro-hole 2313 means that it forms a network channel that is interconnected in three-dimensional space, which can specifically adopt laser etching or 3D printing process to form a cheese-like micro-hole structure that is interconnected in the heat conduction plate 2312, so as to increase the heat conduction surface area and promote the flow of medium, and realize three-dimensional uniform heat conduction.

[0060] In the embodiment, the temperature control assembly is embedded in the bottom of the first, second and third variable curved surface segments respectively, so that the temperature of each curved surface segment can be independently adjusted in stages, and the change amount of the curvature radius of each curved surface segment can be accurately matched, so that the curvature radius of the deformable curved surface 2311 is continuously and smoothly reduced, the accuracy requirement of the progressive optical curved surface of the lens is fully met, and the optical distortion caused by the dynamic fine adjustment of the existing fixed curved surface is avoided. In addition, the heat conduction cavity of the temperature control assembly is matched with the heat conduction plate 2312 with three-dimensional interconnected micropores, so that the heat conduction medium (such as heat conduction oil) can be uniformly diffused through the grid-shaped micropores, the heat can be uniformly conducted in the whole curved surface segment, and the local temperature deviation problem of the existing overall temperature control is completely solved. The stability of the temperature step change of each curved surface segment during the injection molding is ensured, and the temperature is kept constant during the pressure maintaining and cooling stage, so that the unexpected deformation of the deformable curved surface 2311 caused by the local temperature difference is avoided, the accurate curved surface shape is ensured during the curing process of the lens, and the optical accuracy and yield of the finished product are improved. The problems of insufficient curved surface adjustment accuracy and local temperature fluctuation caused by the existing overall temperature control are solved.

[0061] In a further optional embodiment, referring to Figure 3 and Figure 4 A pushing mechanism is further arranged between the movable die 1 and the fixed die 2, and the pushing mechanism is used to push the movable die 1 to reciprocate on the fixed die 2 to perform the mold opening and closing action. The pushing mechanism includes a cylinder 41 and a guide assembly 42. The cylinder 41 is symmetrically arranged on both sides of the fixed die 2, and the output end of the cylinder 41 is vertically upward and connected with the movable die table 11. The guide assembly 42 is symmetrically arranged on both sides of the inside of the fixed die cavity 21, and the guide assembly 42 includes a guide column 421 with a top end recessed inward to form an accommodating cavity, and a guide slide rod 422 slidingly arranged in the accommodating cavity of the guide column 421 and extending to the outside of the accommodating cavity with the top end connected with the movable die table 11.

[0062] In the embodiment, the cylinder 41 of the pushing mechanism is symmetrically arranged on both sides of the fixed die 2, and the output end is connected with the movable die table 11, so that balanced vertical driving force can be provided for the movable die 1, and the inclination and deviation of the movable die 1 during the mold opening and closing can be avoided, and the coaxial alignment stability of the movable die 1 and the fixed die 2 is ensured. The guide slide rod 422 of the guide assembly 42 slides along the accommodating cavity of the guide column 421, so that the movement track of the movable die 1 can be accurately constrained, the lateral shaking during the mold opening and closing can be offset, the position error of the fixed die plate 12 and the molding cavity 23 can be greatly reduced, and the stable and reliable mold opening and closing action can be ensured. In addition, the misalignment of the lens edge and the poor fitting of the optical curved surface caused by the mold alignment deviation can be avoided through accurate guidance, and the production stability and yield of the finished product are improved.

[0063] Specifically, during the clamping process, when the movable mold table 11 is driven by the cylinder 41 to move downward, the guide slide rod 422 slides downward in the accommodating cavity of the guide column 421, and the contact surface between the guide slide rod 422 and the inner wall of the guide column 421 forms a double-guiding constraint, which limits the freedom of the movable mold table 11 in the horizontal direction, and further, the matching structure of the guide slide rod 422 and the guide column 421 can offset the deflection torque caused by mechanical clearance or uneven stress, thereby ensuring the accurate alignment of the shaping mold plate 12 and the molding cavity 23; during the mold opening process, the upward path of the guide slide rod 422 is strictly limited by the inner cavity of the guide column 421, so that the movable mold table 11 maintains a vertical motion trajectory, avoiding damage to the lens surface caused by motion deviation. At the same time, the linear reciprocating motion of the guide slide rod 422 provides a linkage power source for the subsequent airflow cleaning mechanism, realizing the synchronous execution of the mold opening action and the cleaning operation.

[0064] Embodiment 2:

[0065] Based on the above embodiment 1, further as shown in Figure 3 and Figure 4 The airflow cleaning mechanism includes a gas reservoir 2411 arranged in the accommodating cavity in the guide column 421, a piston push plate 2412 is arranged to slide in the gas reservoir 2411 and sealingly matches the gas reservoir 2411, a gas storage area 2413 is formed between the upper part of the piston push plate 2412 and the gas reservoir 2411, and the upper part of the piston push plate 2412 is provided with a connecting rod penetrating to the outside of the gas reservoir 2411, the connecting rod is slidingly sealed with the gas reservoir 2411 and the top end of the connecting rod is connected with the bottom end of the guide slide rod 422, and a micro-slit nozzle 2415 is further arranged at a position corresponding to the progressive light curve surface of the lens on the side of the molding cavity 23, and the micro-slit nozzle 2415 is connected in communication with the gas storage area 2413 through an airflow pipeline 2414.

[0066] It should be understood that when the progressive multi-focal lens is injection molded, it should be understood that the progressive light curve surface of the core optical structure determines that the molding cavity 23 needs to be designed as an irregular curved surface, which brings great inconvenience to the exhaust and cleaning of the traditional mold; first, the gas generated by the extrusion of the resin melt during the injection of the traditional mold is easy to be retained in the injection mold cavity, which finally leads to the formation of bubbles or pinholes in the lens, seriously damaging the light transmittance and optical uniformity of the lens, and greatly reducing the product yield; second, the lens needs to be cleaned after molding to remove the injection residual debris or trace resin overflow, and the traditional cleaning method either relies on manual wiping, which easily causes surface scratches of the precise structure of the progressive light curve surface due to uneven manual operation force, or needs to be equipped with an independent cleaning device such as a high-pressure gas pump and a mechanical arm, which not only increases the overall volume and manufacturing cost of the mold, but also prolongs the process time of single molding.

[0067] Therefore, the embodiment is characterized in that the structure of the air flow cleaning mechanism is innovated, so that the linkage air flow cleaning mechanism is guided by the guiding assembly 42 during the mold opening and closing actions, and the linkage air flow cleaning mechanism can clean and blow the molded lens product synchronously and accurately during the mold opening process, and the excess gas in the forming cavity 23 can be sucked and discharged during the mold closing, so as to avoid the influence of bubble residues on the lens injection quality. Specifically,

[0068] The air flow cleaning mechanism of the embodiment is characterized in that the air cylinder 2411 is ingeniously arranged in the accommodating cavity of the guiding column 421, the guiding slide rod 422 is connected with the movable mold table 11, the piston push plate 2412 moves synchronously with the guiding slide rod 422 through the connecting rod, the efficient cooperation between the mold opening and closing actions of the movable mold 1 and the exhaust cleaning function is realized, the guiding slide rod 422 drives the piston push plate 2412 to slide downward along the air cylinder 2411 when the guiding slide rod 422 moves downward with the movable mold table 11 during the downward movement of the movable mold 1 and the mold closing of the fixed mold 2, the volume of the air storage area 2413 increases to form a negative pressure, the excess gas in the forming cavity 23 is accurately extracted through the micro-slit nozzle 2415 in communication with the side surface of the forming cavity 23 (corresponding to the progressive light ray surface of the lens) and enters the air storage area 2413 through the air flow pipeline 2414, compared with the traditional independent exhaust groove, the gas in the dead angle of the mold cavity can be more completely discharged, the bubbles caused by the gas residues during the resin injection are effectively avoided, and the lens light transmittance is ensured. When the mold is opened, the movable mold 1 is pushed upward by the air cylinder 41, the movable mold table 11 at the bottom drives the molded lens product to move upward to gradually move out of the injection mold cavity through the fixed mold plate 12, the guiding slide rod 422 drives the piston push plate 2412 to slide upward during the upward movement of the guiding slide rod 422 with the movable mold table 11, the air storage area 2413 is compressed to form a high-pressure air flow, the high-pressure air flow enters the micro-slit nozzle 2415 through the air flow pipeline 2414 and directly acts on the outer optical surface of the lens to blow, so that the linkage air flow cleaning mechanism can be used to complete the debris blowing without starting an independent cleaning device, and the position design of the micro-slit nozzle 2415 corresponding to the lens surface can ensure that the blowing is accurately covered in the optical area, and the risk of scratching the surface by manual cleaning is avoided. The piston push plate 2412 is driven to move by the mechanical energy of the mold opening and closing actions, the mechanical movement is directly converted into the air flow movement of the air flow cleaning mechanism, the external power source and control elements are saved, the exhaust thoroughness and cleaning efficiency are improved, the mold structure is further simplified, the additional energy consumption and process time are reduced, and the injection quality and production efficiency of the progressive multifocal lens are significantly improved.

[0069] In some optional embodiments, the micro-slit nozzle 2415 is in the shape of a narrow slit, and a spill-proof plug made of high-temperature-resistant silicone rubber is arranged at the outlet end of the micro-slit nozzle 2415.

[0070] The anti-overflow plug made of high-temperature-resistant silicone rubber is arranged at the outlet end of the micro-gap nozzle 2415. The silicone rubber can adapt to the high-temperature environment in the mold cavity during the injection molding process without failure, and can tightly seal the nozzle outlet during mold clamping to avoid the overflow of molten resin from the nozzle to contaminate the molding cavity 23 or the lens surface, ensure the optical precision of the lens, and be smoothly pushed away by the high-pressure gas flow in the gas storage area 2413 during mold opening and blowing, without hindering the cleaning of the lens outer optical surface by high-pressure gas, thereby realizing the mutual cooperation of the anti-overflow and cleaning functions of the injection molding mold.

[0071] Specifically, during the mold clamping stage, when the shaping template 12 and the deformable template 231 are closed, the anti-overflow plug is elastically deformed by the shaping template 12, and the tapered plug body tightly fits the inner wall of the outlet end of the micro-gap nozzle 2415 to form a physical sealing barrier. During this process, high-temperature resin cannot enter the inside of the nozzle through the closed anti-overflow plug, thereby avoiding blockage of the flow channel after solidification and avoiding the generation of burrs and convex points and other defects on the lens product during injection molding. During the mold opening stage, the guiding slide rod 422 drives the piston push plate 2412 to compress the gas storage area 2413 to generate a high-pressure gas flow, and the gas flow pressure acts on the inside of the anti-overflow plug. When the pressure exceeds the resistance to deformation of the plug, the plug elastically expands outward, allowing the gas flow to be sprayed through the gap formed by the expansion, thereby achieving lens surface cleaning.

[0072] In some optional embodiments, further referring to FIGS. 1, 2 and 3, Figure 5 and Figure 6 the ejector mechanism 25 is further arranged on the movable mold 1. The ejector mechanism 25 includes an ejector cavity 251 symmetrically arranged in the movable mold base 11 and close to the position of the injection gate 131. The bottom of the ejector cavity 251 penetrates the shaping template 12, and a ejector pin base 252 is slidingly fitted in the inside of the ejector cavity 251. The ejector pin base 252 is sealingly fitted with the bottom opening of the ejector cavity 251, and an ejector oil cylinder 253 is further connected to the upper part of the ejector pin base 252.

[0073] It should be noted that, in this embodiment, through the setting of the ejection mechanism 25, after the lens has been cured, the ejection cylinder 253 drives the ejector plate 252 to move downward along the ejection cavity 251. The bottom of the ejector plate 252 passes through the shaping template 12 and acts directly on the edge area of ​​the lens. Since the ejection cavity 251 is symmetrically distributed on both sides of the injection gate 131, the force application point of the ejector plate 252 avoids the core optical surface of the lens, thus preventing indentations and scratches on the optical area during ejection, ensuring the optical accuracy of the lens. Furthermore, the ejection force passes through the high-strength structure of the gate area. The force is evenly transferred to the lens, avoiding lens warping and deformation caused by local stress concentration. The sealing fit between the ejector platen 252 and the opening of the ejection cavity 251 effectively prevents resin from seeping in during the injection molding stage, ensuring the cleanliness of the inside of the ejection mechanism 25 and avoiding ejector jamming caused by residue accumulation. Furthermore, the stable driving force provided by the ejection cylinder 253, combined with the integral sliding structure of the ejector platen 252, ensures that the ejection force is evenly transferred to the lens, ensuring complete separation of the lens from the shaping template 12 and avoiding lens deformation and edge damage caused by uneven local stress.

[0074] Understandably, in this embodiment, when the moving mold 1 opens and the ejector mechanism 25 ejects the lens product from the shaping template 12, it faces the inevitable "gate pull problem" after injection molding. That is, during the injection molding process, the molten resin needs to enter the molding cavity 23 through the injection gate 131. After the resin solidifies, the lens edge and the residual resin in the gate channel will naturally form a "pulling gate" (i.e., the connection structure between the lens and the residual resin in the gate). At this time, the ejector pin 252 of the ejector mechanism 25 applies downward force along the ejection cavity 251. The ejection force directly acts on the non-optical area of ​​the lens edge. Through the separation tendency of the lens and the shaping template 12, the lens is forcibly pulled to break the pulling gate. However, since the connection section of the pulling gate is an irregular interface formed by the natural solidification of the resin, small resin burrs are easily left at the edge of the break, and slight tearing occurs, resulting in the break surface not being a flat plane.

[0075] In this embodiment, it is further preferred that... Figure 6 As shown in the diagram, a flat cutter 26 is provided on the side of the ejector mechanism 25, and a wedge-shaped linkage structure is provided between the flat cutter 26 and the ejector plate 252. When the ejector plate 252 is ejected, the linear motion of the ejector plate 252 moving downward along the ejection cavity 251 can be guided by the wedge-shaped linkage structure on its side to be converted into a lateral motion of the flat cutter 26, so that the flat cutter 26 laterally penetrates into the injection gate 131 to perform a flat cut on the gate connection part.

[0076] Specifically, the wedge linkage mechanism includes a sliding slot 261 opened on the side of the ejection cavity 251 corresponding to the side of the injection gate 131, and the length direction of the sliding slot 261 is parallel to the axial direction of the ejection cavity 251, and the bottom end of the sliding slot 261 does not penetrate the shaping mold plate 12, and a horizontal cavity 262 connected with the injection gate 131 is arranged at the lower part of the side of the sliding slot 261 away from the ejection cavity 251, and the trimming cutter 26 is installed in the horizontal cavity 262 through the reset spring, and the sliding slot 261 also slidably connects with a wedge block 263 connected with the side of the ejector pin platform 252, and the end of the trimming cutter 26 corresponding to the sliding slot 261 extends into the sliding slot 261 and slidably connects with the inclined surface of the wedge block 263; so that when the ejector pin platform 252 moves downward, the wedge block 263 slides downward in the sliding slot 261, and when the wedge block 263 contacts the end of the trimming cutter 26, the inclined surface of the wedge block 263 is in close contact with the end of the trimming cutter 26, so that as the ejector pin platform 252 continues to apply force downward, the downward pressure of the ejector pin platform 252 will generate a horizontal component force on the trimming cutter 26 through the inclined surface of the wedge block 263, and the component force can overcome the pre-tightening force of the reset spring, and then push the trimming cutter 26 to slide along the horizontal cavity 262 to the direction of the injection gate 131, so that the trimming cutter 26 gradually cuts into the center area of the gate connecting part, and pre-cuts the gate, and forms a smooth cutting seam on the connecting cross section, and then the ejector pin platform 252 continues to move downward, and the connecting force between the lens and the gate is concentrated on the cutting seam, and the directional fracture is realized along the cutting seam, so as to completely avoid irregular tearing during natural fracture.

[0077] After the ejection action is completed (the lens is completely separated from the shaping mold plate 12), the ejector cylinder 253 drives the ejector pin platform 252 to reset upward along the ejection cavity 251, at this time the wedge block 263 on the side of the ejector pin platform 252 is gradually away from the end of the trimming cutter 26 and is not in contact, at this time the pressure between the two disappears, and the reset spring pulls the trimming cutter 26 to slide reversely along the horizontal cavity 262 under the action of its own elastic force, until the trimming cutter 26 is completely withdrawn into the horizontal cavity 262 (to avoid the cutter contacting the molten resin during the injection molding stage), and the trimming cutter assembly is reset, ready for the next injection molding.

[0078] Further, through the above-mentioned ejection-trimming-reset linkage process, the gate is broken along the pre-set cutting seam, the fracture surface is more smooth and accurate, the difficulty of the subsequent trimming process is greatly reduced, the demolding and trimming are simultaneously completed, no additional trimming station and power source are needed, the integrated efficiency of lens molding is further improved, and the trimming cutter always acts on the non-optical area, completely avoiding the influence on the core optical performance of the lens, thereby greatly improving the use effect of the injection mold.

[0079] Embodiment 3:

[0080] Based on the injection mold of the progressive multi-focal lens of the above embodiment, an injection molding process of the progressive multi-focal lens is specially disclosed, specifically, as shown in Figure 7 The process comprises the following steps:

[0081] Step 1, injection preparation, preheating the temperature control assembly of the deformable template 231 to adjust the initial temperature of the first, second and third deformation curved sections, so that the deformable curved surface 2311 is initially adapted to the initial accuracy of the lens progressive light curve, and the molten lens resin is prepared for use;

[0082] Step 2, mold closing operation and forming cavity 23 exhaust, start the cylinder 41 of the push mechanism, make the output end of the cylinder 41 contract and drive the movable mold 1 to move downward and close to the fixed mold 2, in this process, the anti-overflow plug is not completely compressed, and the outlet end of the micro slit nozzle 2415 is in the on state, the guide slide rod 422 moves downward along the containing cavity of the guide column 421 with the movable mold table 11, synchronously pushes the piston push plate 2412 to move downward along the air cylinder 2411 through the connecting rod, so that the volume of the air storage area 2413 increases to form negative pressure, and the negative pressure extracts the excess gas in the forming cavity 23 through the micro slit nozzle 2415 to avoid air bubbles in the subsequent injection molding, as the movable mold 1 continues to close to the fixed mold 2, the shaping template 12 gradually extends into the forming cavity 23, as the shaping template 12 gradually extrudes, the anti-overflow plug is compressed and completely closed under pressure, until the movable mold 1 and the fixed mold 2 are completely closed, at this time the shaping template 12 and the deformable template 231 are closed to form the injection mold cavity 3;

[0083] Step 3, injection molding, the molten lens resin is delivered to the injection sprue 131 of the shaping template 12 through the injection runner 13 of the movable mold 1, and uniformly flows into the injection mold cavity 3 through the injection sprue 131 until it is filled, in the injection process, the temperature control assembly is controlled to pass through the heat conduction pipeline to respectively pass into the temperature control medium in the heat conduction cavity, so as to adjust the curvature radius of the deformable curved surface 2311 through the temperature step change, so as to make it adapt to the curved surface accuracy of the lens progressive light curve in real time;

[0084] Step 4, pressure holding and curing, maintaining the initial pressure of the movable mold 1 and the fixed mold 2 to keep pressure, to compensate for the shrinkage of the resin during cooling, while maintaining the temperature stability of the temperature control assembly, to avoid the unintended curvature change of the deformable curved surface caused by temperature fluctuation, and uniformly conducting heat through the heat conduction micro holes 2313 of the heat conduction plate 2312, so that the resin in the injection mold cavity 3 slowly cools to the curing temperature along the shape of the deformable curved surface 2311, to ensure that the resin always adheres to the deformable curved surface 2311 during the curing process, to avoid the optical accuracy deviation of the lens caused by the deformation of the curved surface, until the resin is completely cured;

[0085] Step 5, mold opening and air flow purging, the air cylinder 41 of the pushing mechanism is started again to drive the movable mold 1 to move upward to gradually move away from the fixed mold 2 to perform the mold opening action, at this time, the guide slide rod 422 in the guide column 421 moves upward and drives the piston push plate 2412 to compress the gas storage area 2413 and gradually form high pressure gas flow into the pipeline, and then open the anti-overflow plug through the high pressure gas flow, so that the high pressure gas in the gas storage area 2413 continuously purges the outer optical surface of the lens through the micro-gap nozzle 2415 to remove the surface debris;

[0086] Step 6, ejection and taking out, the ejection oil cylinder 253 of the ejection mechanism 25 is started to drive the ejector base 252 to move downward along the ejection cavity 251, the ejector base 252 passes through the shaping mold plate 12 to eject the lens, after the lens is taken out, the ejector base 252 is controlled to reset, and the single injection molding work is completed.

[0087] It should be understood that, compared with the prior art, the traditional injection molding process uses a fixed curved mold plate, which cannot compensate for the shrinkage and deformation of the resin, and the exhaust groove can only passively exhaust gas;

[0088] The injection molding process of the scheme is deeply coordinated with the matched injection mold structure. In the injection preparation, the initial temperature of the first to third deformation curved surface sections is adjusted by the preheating temperature control assembly, the deformable curved surface 2311 is initially adapted to the progressive light ray curved surface of the lens in advance, laying a foundation for subsequent forming precision, and avoiding the increase of subsequent adjustment difficulty caused by initial curved surface deviation. In the mold closing operation and the forming cavity 23 exhaust stage, the mold 1 is driven to move downward by the push mechanism cylinder 41, the guide slide rod 422 and the connecting rod drive piston push plate 2412 are synchronously linked to move downward to form negative pressure, the excess gas in the forming cavity 23 is extracted through the micro slit nozzle 2415, the lens bubble problem caused by incomplete exhaust of the independent exhaust groove in the prior art is solved from the root, and at the same time, the anti-glue overflow plug is gradually compressed and closed by the moving mold 1, effectively blocking the molten resin from overflowing from the nozzle during injection molding, and the subsequent glue overflow trimming process is omitted. In the injection molding stage, the temperature control assembly is used to respectively introduce temperature control medium into the heat conduction cavities of each deformation curved surface section to realize temperature step change, and the curvature radius of the deformable curved surface 2311 is adjusted in real time to accurately adapt to the dynamic fitting demand of the lens progressive light ray curved surface in the resin flow process, and the optical distortion problem caused by the fixed curved surface unable to adjust with the resin state is solved. In the pressure maintaining and curing stage, the temperature of the temperature control assembly is kept stable to avoid unexpected deformation of the deformable curved surface 2311, and the three-dimensional intercommunication type micro hole array of the heat conduction plate 2312 uniformly conducts heat to ensure that the resin is slowly cooled and cured along the adapted curved surface, which not only compensates for the resin shrinkage, but also avoids the curved surface fitting deviation caused by uneven cooling, and guarantees the optical precision of the lens. In the mold opening and air flow blowing stage, the guide slide rod 422 and the piston push plate 2412 are compressed to form high pressure gas flow in the gas storage area 2413 by the upward movement of the mold 1, the anti-glue overflow plug is opened by the high pressure gas, and the lens surface is blown through the micro slit nozzle 2415, without the need for additional cleaning device, the resin debris can be efficiently removed, the risk of scratching the optical surface by manual cleaning is avoided, and the production efficiency is improved. In the ejection and taking stage, the ejector cylinder 253 drives the ejector pin table 252 to move downward along the ejection cavity 251 and act on the non-optical area of the lens, and cooperates with the sealing design of the ejector pin table 252 and the ejection cavity 251 to ensure the stability of the ejection and avoid the deformation and indentation of the lens, and prevent the resin from penetrating into the mechanism to affect the subsequent action, finally realizing the cooperation of high precision, high efficiency and high yield in single injection molding process, and solving the problems of the existing process in precision control, efficiency improvement and defect avoidance.

[0089] That is, the injection molding process of the embodiment realizes dynamic control of the progressive multifocal lens curved surface forming precision, solves the curvature deviation problem caused by fixed structure, improves the gas exhaust efficiency and surface cleanliness through the linkage design of mold closing and mold opening cleaning, and effectively suppresses the influence of temperature fluctuation on curved surface precision through the cooperation of regional temperature control and heat conduction structure, ensuring that the optical performance of the lens meets the design requirements.

[0090] It is to be noted that the structures, proportions, sizes, etc. shown in the drawings attached to the present specification are schematic diagrams, which only serve to cooperate with the content disclosed in the specification for understanding and reading by those skilled in the art, and are not used to define the limiting conditions for the implementation of the present application, and therefore do not have technical substantive significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that can be produced and the purposes that can be achieved by the present application, should still fall within the scope of the technical content disclosed by the present application.

[0091] At the same time, the terms related to the direction position such as "upper", "lower", "left", "right", "middle" and the like cited in the present specification are only for the convenience of clear description, and are not used to limit the scope of the implementation of the present application. The change or adjustment of the relative relationship, without substantially changing the technical content, is also considered as the implementation range of the present application.

Claims

1. An injection mold for a progressive addition lens, comprising a movable mold (1) and a fixed mold (2) arranged opposite each other from top to bottom, characterized in that, The top of the fixed mold (2) is provided with a fixed mold cavity (21), a forming table (22) is arranged below the inside of the fixed mold cavity (21), the top of the forming table (22) is provided with a forming cavity (23), the bottom of the movable mold (1) is provided with a movable mold table (11) extending into the fixed mold cavity (21), the bottom of the movable mold table (11) is provided with a fixed forming plate (12) matched with the forming cavity (23), and the injection mold cavity (3) for lens forming is formed by the fixed forming plate (12) and the forming cavity (23) after the movable mold (1) and the fixed mold (2) are closed to each other; A deformable mold plate (231) corresponding to the progressive light ray surface of the lens is arranged at the bottom of the forming cavity (23), the inside of the deformable mold plate (231) is provided with a temperature control assembly, and the temperature change is controlled by the temperature control assembly to realize the accurate adjustment of the curvature of the deformable mold plate (231); A pushing mechanism is further arranged between the movable mold (1) and the fixed mold (2), the pushing mechanism is used for pushing the movable mold (1) to reciprocate on the fixed mold (2) to realize the opening and closing of the mold, and the pushing mechanism comprises a gas cylinder (41) and a guide assembly (42); An airflow cleaning mechanism is further arranged in the fixed mold cavity (21), the airflow cleaning mechanism blows the outer optical surface of the lens during the opening of the movable mold (1), and the mold is opened and closed under the accurate guidance of the guide assembly (42), the linkage airflow cleaning mechanism is driven to blow and clean the injection-molded lens product accurately and synchronously during the opening of the mold, and the excess gas in the forming cavity (23) can be sucked and discharged during the closing of the mold; An injection flow channel (13) is arranged through the inside of the movable mold (1), the bottom of the injection flow channel (13) is communicated with an injection gate (131) on the fixed forming plate (12), the injection gate (131) is symmetrically arranged at the bottom of the fixed forming plate (12) and is arranged in a direction away from each other, and the inner diameter of the injection gate (131) gradually decreases along the flow direction of the pouring medium; The top of the deformable mold plate (231) is inwardly recessed and forms a deformable curved surface (2311) matched with the progressive light ray surface of the lens, and the deformable curved surface (2311) comprises a first deformation curved surface section, a second deformation curved surface section and a third deformation curved surface section with gradually decreasing and smoothly transitioned curvature radii: The temperature control assembly is respectively embedded at the bottom of the first deformation curved surface section, the second deformation curved surface section and the third deformation curved surface section, and the temperature step change of each deformation curved surface section is adjusted by the temperature control assembly, so that the curvature radii of the first deformation curved surface section, the second deformation curved surface section and the third deformation curved surface section are adjusted to be matched with the progressive light ray surface of the lens; The temperature control assembly comprises a heat conduction cavity, the heat conduction cavity is communicated with the outside through a heat conduction pipeline, a heat conduction plate (2312) is arranged in the inside of the heat conduction cavity, a heat conduction micro-hole (2313) is arranged in the heat conduction plate (2312), the heat conduction micro-hole (2313) is a three-dimensional intercommunication type through hole array and forms a grid structure with space intersection. The air flow cleaning mechanism comprises a gas storage cylinder (2411) arranged in the containing cavity of the guide column (421), a piston push plate (2412) is slidingly arranged in the gas storage cylinder (2411) and sealingly matched with the gas storage cylinder (2411), a gas storage area (2413) is formed between the upper portion of the piston push plate (2412) and the gas storage cylinder (2411), the upper portion of the piston push plate (2412) is provided with a connecting rod penetrating to the outside of the gas storage cylinder (2411), the connecting rod is slidingly sealed with the gas storage cylinder (2411) and the top end of the connecting rod is connected with the bottom end of the guide sliding rod (422), and a micro slit nozzle (2415) is further arranged at the position corresponding to the lens progressive light ray surface on the side of the forming cavity (23), the micro slit nozzle (2415) is connected with the gas storage area (2413) through the air flow pipeline (2414). The ejector mechanism (25) is further arranged on the movable die (1), the ejector mechanism (25) comprises an ejector cavity (251) symmetrically arranged in the movable die table (11) and close to the position of the injection gate (131), the bottom of the ejector cavity (251) penetrates the shaping die plate (12), and an ejector pin table (252) is slidingly matched in the ejector cavity (251), the ejector pin table (252) is sealingly matched with the bottom opening of the ejector cavity (251), and an ejector oil cylinder (253) is further connected to the upper portion of the ejector pin table (252). The ejector mechanism (25) is further arranged on the movable die (1), the ejector mechanism (25) comprises an ejector cavity (251) symmetrically arranged in the movable die table (11) and close to the position of the injection gate (131), the bottom of the ejector cavity (251) penetrates the shaping die plate (12), and an ejector pin table (252) is slidingly matched in the ejector cavity (251), the ejector pin table (252) is sealingly matched with the bottom opening of the ejector cavity (251), and an ejector oil cylinder (253) is further connected to the upper portion of the ejector pin table (252), a flat cutter (26) is arranged on the side of the ejector mechanism (25), and a wedge linkage structure is arranged between the flat cutter (26) and the ejector pin table (252), so that when the ejector pin table (252) is ejected, the linear motion of the ejector pin table (252) moving downward along the ejector cavity (251) can be guided and converted into the transverse motion of the flat cutter (26) through the wedge linkage structure on the side of the flat cutter (26), so that the flat cutter (26) transversely penetrates into the injection gate (131) to perform flat cutting on the water gap connection part.

2. An injection mold for a progressive addition lens according to claim 1, wherein The gas cylinder (41) is symmetrically arranged on both sides of the fixed die (2) table, and the output end thereof is vertically upward and connected with the movable die table (11), and the guide assembly (42) is symmetrically arranged on both sides of the inside of the fixed die cavity (21), and the guide assembly (42) comprises a guide column (421) with a top end recessed inward to form a containing cavity, and a guide sliding rod (422) slidingly arranged in the containing cavity of the guide column (421) and extending to the outside of the containing cavity and connected with the movable die table (11).

3. The injection mold for a progressive addition lens according to claim 1, wherein The outlet end of the micro-gap nozzle (2415) is also provided with an anti-overflow plug made of high-temperature-resistant silicone rubber.

4. Injection molding process of an addition multifocal lens, based on an injection molding mold of an addition multifocal lens according to any one of claims 1 to 3, characterized in that, The process comprises the following steps: Injection preparation, preheating the temperature control assembly of the deformable template (231) to adjust the initial temperature of the first, second and third deformation curved sections, so that the deformable curved surface (2311) maintains initial fitting accuracy with the progressive light ray curved surface of the lens, and the molten lens resin is prepared for use; The mold closing operation and the venting of the molding cavity, starting the cylinder (41) of the push mechanism, causing the output end of the cylinder (41) to contract and drive the movable mold (1) to move downward and approach the fixed mold (2), during which the anti-overflow plug is not fully compressed, and the outlet end of the micro-gap nozzle (2415) is in a conductive state, the guide slide rod (422) moves downward along the containing cavity of the guide column (421) with the movable mold table (11), and the connecting rod synchronously pushes the piston push plate (2412) to move downward along the gas reservoir (2411), so that the volume of the gas storage area (2413) increases to form negative pressure, and the negative pressure extracts the excess gas in the molding cavity (23) through the micro-gap nozzle (2415), avoiding air bubbles in the subsequent injection molding, as the movable mold (1) continues to approach the fixed mold (2), the shaping template (12) gradually extends into the molding cavity (23), and as the shaping template (12) gradually extrudes, the anti-overflow plug is compressed and completely closed under pressure until the movable mold (1) and the fixed mold (2) are completely closed, at which point the shaping template (12) and the deformable template (231) form an injection mold cavity (3); Step 3, injection molding, the molten lens resin is delivered to the injection gate (131) of the shaping template (12) through the injection runner (13) of the movable mold (1), and uniformly flows into the injection mold cavity (3) through the injection gate (131) until it is filled, during the injection molding process, the temperature control assembly is controlled to pass through the heat conduction pipeline to introduce temperature control medium into the heat conduction cavity, so as to adjust the radius of curvature of the deformable curved surface (2311) through temperature step change, so as to adapt the curved surface accuracy of the lens progressive light ray curved surface in real time; Pressure holding and curing, maintaining the initial pressure of the movable mold (1) and the fixed mold (2) to compensate for the shrinkage of the resin during cooling, while maintaining the temperature stability of the temperature control assembly to avoid unintended curvature changes of the deformable curved surface due to temperature fluctuations, and uniformly conducting heat through the heat conduction micro-holes (2313) of the heat conduction plate (2312) to slowly cool the resin in the injection mold cavity (3) along the shape of the deformable curved surface (2311) to the required temperature for solidification, ensuring that the resin always adheres to the deformable curved surface (2311) during the solidification process, avoiding optical precision deviation of the lens caused by curved surface deformation, until the resin is completely solidified; The mold is opened and the air flow is purged. The air cylinder (41) of the pushing mechanism is started again to drive the movable mold (1) to move upward to gradually move away from the fixed mold (2) to perform the mold opening action. At this time, the guide slide rod (422) in the guide column (421) moves upward and drives the piston push plate (2412) to compress the gas storage area (2413) and gradually form a high-pressure gas flow into the pipeline. Then, the high-pressure gas flow opens the anti-overflow plug to continuously blow the outer optical surface of the lens through the micro-gap nozzle (2415) to remove the surface debris. The ejection mechanism (25) is started to drive the ejection oil cylinder (253) to drive the ejector table (252) to move downward along the ejection cavity (251). The ejector table (252) passes through the shaping mold plate (12) to eject the lens. After the lens is taken out, the ejector table (252) is controlled to reset to complete the single injection molding work.

Images