CN114603891A

CN114603891A - Manufacturing method of thick-wall lens and injection mold

Info

Publication number: CN114603891A
Application number: CN202210162872.2A
Authority: CN
Inventors: 朱金云
Original assignee: Taizhou Huangyan Jingjiang Molding Co ltd
Current assignee: Taizhou Huangyan Jingjiang Molding Co ltd
Priority date: 2022-02-22
Filing date: 2022-02-22
Publication date: 2022-06-10

Abstract

The invention belongs to the technical field of lens processing, and particularly relates to a manufacturing method and an injection mold of a thick-walled lens, wherein the thick-walled lens is layered according to the thickness direction of the thick-walled lens, divided into a pre-molding layer and a post-molding layer, and subjected to graded injection molding; the end face of the pre-molding layer is an arc-shaped face protruding outwards, the end face of the rear molding layer is a plane, the layered face of the thick-wall lens is a concave-convex undulating face, and the area ratio of the cross section of the pre-molding layer to the cross section of the rear molding layer is 0.6-0.7. The method effectively shortens the molding cycle of the thick-wall lens, reduces the wall thickness of the post-molding layer by increasing the wall thickness of the pre-molding layer, greatly shortens the cooling cycle difference between the primary molding and the secondary molding, and further avoids the material from degrading.

Description

Manufacturing method of thick-wall lens and injection mold

Technical Field

The invention belongs to the technical field of lens processing, and particularly relates to a manufacturing method of a thick-wall lens and an injection mold.

Background

The lens is an optical element which is made of transparent substances and the surface of which is a part of a spherical surface, and because of the limitation of optical design, the wall thickness of a plastic element for manufacturing the lens is usually between 10mm and 30mm, so if the requirement of high precision is to be met, the lens can only be produced by injection molding, and the production cycle is long. Due to the design and integration of the functions of the complex and precise optical elements, the lens as a whole often has a large wall thickness difference.

For thicker injection molded regions, the solidification rate can be significantly slower than for thinner regions, premature solidification can affect the pressure transfer of the melt, thereby affecting the accuracy of the injection molding production, and production efficiency tends to be low because thick-walled lenses tend to have longer cooling times, typically requiring 5 to 30 minutes. Because the production of high-efficient high accuracy's lens can't be realized to monolayer injection moulding processing, consequently, the thick wall lens adopts multilayer injection moulding technology production mostly at present, through having reduced the individual layer shrinkage to improve the shaping precision, promoted the economic efficiency of this type of lens component production then.

The existing processing method for the lens adopts the layered injection molding as shown in fig. 1, which is composed of two spherical matching surfaces, namely a pre-molding layer A1 at the lower layer and a post-molding layer A2 at the upper layer, when in injection molding, because the plastic has lower heat transfer efficiency compared with the mold steel, the cooling time of the pre-molding layer A1 is short, and the cooling time of the post-molding layer A2 is long, on one hand, the molding period of the whole lens is long, on the other hand, the glue in the barrel can stay for a long time, and the relatively long stay time can cause the risk of material degradation, thereby failing to meet the requirement of optical high precision.

Disclosure of Invention

The invention aims to solve the technical problems, and provides a manufacturing method of a thick-wall lens and an injection mold.

In view of the above, the present invention provides a method for manufacturing a thick-walled lens, which comprises the steps of layering a thick-walled lens in a thickness direction thereof, dividing the thick-walled lens into a pre-molding layer and a post-molding layer, and performing step injection molding; the end face of the pre-molding layer is an arc-shaped face protruding outwards, the end face of the rear molding layer is a plane, the layered face of the thick-wall lens is a concave-convex undulating face, and the area ratio of the cross section of the pre-molding layer to the cross section of the rear molding layer is 0.6-0.7.

In the above technical solution, further, the rear molding layer has a symmetrical structure and is sequentially divided into a first portion, a second portion, a third portion and a fourth portion from the middle portion to the side end; the maximum thickness of the thick-walled lens is H, the thickness of the first part is H1, the thickness of the second part is H2, the thickness of the third part is H3, and the thickness of the fourth part is H4;

wherein H1, H is 0.25-0.35; h2, H is 0.5-0.6; h3, H is 0.25-0.35; h4, H is 0.1-0.2.

In any of the above solutions, further, the thick-walled lens has a diameter of L, the first portion has a length of L1, the second portion has a length of L2, the third portion has a length of L3, and the fourth portion has a length of L4;

wherein, L1, L is 0.01; l2, L is 0.05; l3, L is 0.07; l4: l is 0.15; the first part and the second part, the second part and the third part and the fourth part are connected by inclined planes.

An injection mould for the thick-wall lens manufacturing method comprises a first injection moulding station for forming a preformed layer; and a second injection molding station for molding the post-mold layer; after the preformed layer is cooled and formed, the preformed layer on the first injection molding station is rotated to the second injection molding station by the rotating device to be subjected to secondary molding.

In any of the above technical solutions, further, the injection mold further includes:

the fixed die base plate is provided with a main flow channel which penetrates through the fixed die base plate, the main flow channel is provided with a positioning ring for positioning the injection gun, and the two main flow channels are symmetrically arranged on the fixed die base plate;

and a movable mold base plate;

the first injection molding station sequentially comprises a first fixed template, a first core, a first cavity, a first movable template and a first side plate from top to bottom; the first fixed die plate is arranged below the fixed die base plate, the first core is arranged at the lower end of the first fixed die plate, the upper end of the first fixed die plate is communicated with one main runner, the lower end of the first fixed die plate is communicated with a first branch runner of the first core, the first cavity is arranged on the first movable die plate and is over against the first core, after die assembly is carried out, a cavity for forming a pre-forming layer is formed in a space between the first core and the first cavity, the lower end of the first side plate is arranged on the movable die base plate, and the upper end of the first side plate is connected with the first movable die plate;

the second injection molding station sequentially comprises a second fixed mold plate, a second mold core, a second cavity, a second movable mold plate and a second side plate from top to bottom; the second fixed die plate is arranged below the fixed die base plate, the second core is arranged at the lower end of the second fixed die plate, the upper end of the second fixed die plate is communicated with the other main runner, the lower end of the second fixed die plate is communicated with a second branch runner of the second core, the second cavity is arranged on the second movable die plate and is right opposite to the second core, after die assembly is carried out, a cavity of a molded layer is formed in the space between the second core and the second cavity, the lower end of the second side plate is arranged on the movable die base plate, and the upper end of the second side plate is connected with the second movable die plate;

wherein, after the preforming layer cooling shaping, carry out the die sinking, make first die cavity break away from first core, the second die cavity breaks away from the second core, is rotatory 180 by rotary device drive movable mould bedplate afterwards, makes first die cavity subtend second core, second die cavity subtend first core.

In any of the above technical solutions, further, there are two first side plates respectively disposed on two sides of the lower end of the first movable mold plate, and two second side plates respectively disposed on two sides of the lower end of the second movable mold plate.

In any of the above technical solutions, further, the first movable die plate and the second movable die plate are provided with guide cylinders which are arranged upwards, and the bottoms of the first fixed die plate and the second fixed die plate are provided with guide rods which are respectively opposite to the guide cylinders.

The invention has the beneficial effects that: the invention improves the pre-molding layer and the post-molding layer, and the contact surface between the pre-molding layer and the post-molding layer is set to be wavy, so that the cooling period difference of the pre-molding layer and the post-molding layer can be effectively reduced, the problem of uneven cooling of the pre-molding layer and the post-molding layer is solved, and the molding precision of the thick-wall lens is effectively improved.

Drawings

FIG. 1 is a prior art pre-mold layer and post-mold layer configuration;

FIG. 2 is a pre-mold layer and post-mold layer configuration of the present invention;

FIG. 3 is a pre-mold layer and post-mold layer configuration of the present invention;

FIG. 4 is a graph of experimental data for cooling formation of pre-formed and post-formed layers in the prior art;

FIG. 5 is a graph of experimental data for cooling formation of a pre-formed layer and a post-formed layer of the present invention;

FIG. 6 is a schematic view of an injection mold of the present invention;

FIG. 7 is a schematic view of the internal structure of the injection mold of the present invention;

FIG. 8 is an enlarged view at A in FIG. 7;

the reference numbers in the figures are: a1, preforming layer; a2, a rear molding layer; b1, preforming layer; b2, rear molding layer; 1. a first portion; 2. a second portion; 3. a third portion; 4. a fourth part; 10. a fixed die base plate; 11. a main flow channel; 20. a movable mould seat plate; 100. a first fixed template; 110. a first core; 120. a first cavity; 130. a first movable template; 140. a first side plate; 150. a first shunt passage; 200. a second fixed template; 210. a second core; 220. a second cavity; 230. a second movable template; 240. a second side plate; 250. a second branch flow channel; 300. a guide cylinder; 400. a guide bar; 500. a first injection molding channel; 600. a second injection molding channel; 700. a regulator; 710. a valve body; 711. a first chamber; 712. a second chamber; 720. an adjustment head; 730. a connecting plate; 740. connecting ribs; 750. adjusting a rod; 760. a first electromagnet; 770. a second electromagnet; 780. a buffer spring.

Detailed Description

The technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments that can be derived by one of ordinary skill in the art from the embodiments given herein are intended to be within the scope of the present disclosure.

In the description of the present application, it is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present application. For convenience of description, the dimensions of the various features shown in the drawings are not necessarily drawn to scale. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be discussed further in subsequent figures.

It should be noted that the terms "first," "second," and the like in the description and in the claims of the present application are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that embodiments of the application may be practiced in sequences other than those illustrated or described herein, and that the terms "first," "second," and the like are generally used herein in a generic sense and do not limit the number of terms, e.g., the first term can be one or more than one. In addition, "and/or" in the specification and claims means at least one of connected objects, a character "/" generally means that a preceding and succeeding related objects are in an "or" relationship.

It should be noted that in the description of the present application, the orientation or positional relationship indicated by the terms such as "front, back, up, down, left, right", "lateral, vertical, horizontal" and "top, bottom" and the like are generally based on the orientation or positional relationship shown in the drawings for convenience of description and simplicity of description only, and in the case of not making a reverse description, these orientation terms do not indicate and imply that the device or element being referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be construed as limiting the scope of the present application; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

It should be noted that, in the present application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element. Further, it should be noted that the scope of the methods and apparatus of the embodiments of the present application is not limited to performing the functions in the order illustrated or discussed, but may include performing the functions in a substantially simultaneous manner or in a reverse order based on the functions involved, e.g., the methods described may be performed in an order different than that described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

Example 1:

as shown in fig. 2-3, the present embodiment provides a method for manufacturing a thick-walled lens, in which a thick-walled lens is layered in the thickness direction, divided into a pre-molding layer and a post-molding layer, and subjected to step injection molding; the end face of the pre-molding layer is an arc-shaped face protruding outwards, the end face of the rear molding layer is a plane, the layered face of the thick-wall lens is a concave-convex undulating face, and the area ratio of the cross section of the pre-molding layer to the cross section of the rear molding layer is 0.6-0.7.

In this embodiment, the conventional injection molding method of the thick-walled lens is as shown in fig. 1, and is divided into a pre-molding layer a1 and a post-molding layer a2, because the pre-molding layer a1 is made of mold steel on both upper and lower end surfaces thereof during cooling molding, so that the thick-walled lens can be rapidly cooled and molded, and then the post-molding layer a2 is injection molded on the basis of the pre-molding layer a1, so that the upper end surface of the post-molding layer a2 is made of mold steel and the lower end surface is made of plastic pre-molding layer, so that the cooling time of the post-molding layer a2 is much longer than that of the pre-molding layer a1, and the cooling cycle of the two layers is longer, therefore, the glue in the barrel of the injection molding machine is easily degraded, so that the optical accuracy of the thick-walled lens is poor, therefore, the pre-molding layer a1 and the post-molding layer a2 are improved and become a pre-molding layer B1 and a post-molding layer B2 respectively, and the contact surface between the two layers is set in a wave shape, not only can the cooling cycle difference of preforming layer B1 and postforming layer B2 be effectual reduced, but also can make preforming layer B1 and postforming layer B2 be difficult for appearing cooling inhomogeneous problem, the effectual shaping precision that improves the thick wall lens.

As shown in fig. 2-3, in the present embodiment, specifically, the rear molding layer has a symmetrical structure and is sequentially divided into a first portion 1, a second portion 2, a third portion 3, and a fourth portion 4 from the middle portion to the side end; setting the maximum thickness of the thick-walled lens to be H, the thickness of the first part 1 to be H1, the thickness of the second part 2 to be H2, the thickness of the third part 3 to be H3 and the thickness of the fourth part 4 to be H4;

wherein H1, H is 0.25-0.35; h2, H is 0.5-0.6; h3, H is 0.25-0.35; h4, H is 0.1-0.2. Specifically, H1, H is 0.29; h2, H is 0.53; h3, H is 0.29; h4, H is 0.12.

Setting the diameter of the thick-walled lens to be L, the length of the first part 1 to be L1, the length of the second part 2 to be L2, the length of the third part 3 to be L3 and the length of the fourth part 4 to be L4;

wherein, L1, L is 0.01; l2, L is 0.05; l3, L is 0.07; l4: l is 0.15; the first part 1 and the second part 2, the second part 2 and the third part 3 and the fourth part 4 are connected by inclined planes, wherein the inclined planes between the first part 1 and the second part 2 and the inclined planes between the second part 2 and the third part 3 form an included angle of 65 degrees with the horizontal plane, and the inclined planes between the third part 3 and the fourth part 4 form an included angle of 55 degrees with the horizontal plane.

After a number of trials, the time for the pre-form layer a1 to reach the ejection temperature was 428.3s and the time for the post-form layer a2 to reach the ejection temperature was 1205.5s, for comparison, as shown in fig. 4 and 5; the time for the pre-molding layer B1 to reach the ejection temperature is 890.7s, the time for the post-molding layer B2 to reach the ejection temperature is 871.3s, and the molding period of the post-molding layer is shortened by 5.25min compared with that of the former, so that the processing efficiency of the thick-wall lens is effectively improved, and the processing cost is saved.

As shown in fig. 6 and 7, the present embodiment also provides an injection mold for processing a thick-walled lens, wherein a first injection station is included for molding a preform layer; and a second injection molding station for molding the post-mold layer; after the preformed layer is cooled and formed, the preformed layer on the first injection molding station is rotated to the second injection molding station by the rotating device to be subjected to secondary molding.

The injection mold further includes:

the fixed die base plate 10 is provided with a main flow channel 11 which penetrates through the fixed die base plate, a positioning ring for positioning an injection gun is arranged on the main flow channel 11, and two main flow channels 11 are symmetrically arranged on the fixed die base plate 10;

and a movable die base plate 20;

the first injection molding station comprises a first fixed mold plate 100, a first mold core 110, a first cavity 120, a first movable mold plate 130 and a first side plate 140 from top to bottom in sequence; the first fixed die plate 100 is arranged below the fixed die base plate 10, the first core 110 is arranged at the lower end of the first fixed die plate 100, the first fixed die plate 100 is further provided with a main runner 11 of which the upper end is communicated with the main runner, the lower end of the first divided runner 150 is communicated with the first core 110, the first cavity 120 is arranged on the first movable die plate 130 and is opposite to the first core 110, after die assembly, a cavity for forming a pre-forming layer is formed in a space between the first core 110 and the first cavity 120, the lower end of the first side plate 140 is arranged on the movable die base plate 20, and the upper end of the first side plate is connected with the first movable die plate 130;

the second injection molding station comprises a second fixed mold plate 200, a second mold core 210, a second mold cavity 220, a second movable mold plate 230 and a second side plate 240 from top to bottom in sequence; the second fixed die plate 200 is arranged below the fixed die base plate 10, the second core 210 is arranged at the lower end of the second fixed die plate 200, the second fixed die plate 200 is further provided with a second branch runner 250, the upper end of the second branch runner is communicated with the other main runner 11, the lower end of the second branch runner is communicated with the second core 210, the second cavity 220 is arranged on the second movable die plate 230 and is opposite to the second core 210, after die assembly, a cavity of a molded layer is formed in a space between the second core 210 and the second cavity 220, the lower end of the second side plate 240 is arranged on the movable die base plate 20, and the upper end of the second side plate is connected with the second movable die plate 230;

after the preform layer is cooled and formed, the mold is opened to separate the first cavity 120 from the first core 110 and the second cavity 220 from the second core 210, and then the movable mold base plate 20 is rotated by 180 ° by the rotating means to make the first cavity 120 face the second core 210 and the second cavity 220 face the first core 110.

The injection mold has the following working conditions:

primary injection molding: feeding the rubber compound into a main runner 11 above a first injection molding station by an injection molding machine, then flowing the rubber compound into a branch runner on a first fixed mold plate 100 in the main runner 11, finally flowing the rubber compound into a cavity between a first mold core 110 and a first mold cavity 120, after cooling and forming a preformed layer B1, opening the mold to ensure that the first mold cavity 120 is separated from the first mold core 110 and the second mold cavity 220 is separated from the second mold core 210, then driving a movable mold base plate 20 to rotate 180 degrees by a rotating device to ensure that the first mold cavity 120 faces the second mold core 210 and the second mold cavity 220 faces the first mold core 110, wherein the preformed layer B1 is positioned in the first mold cavity 120;

secondary injection molding: the injection molding machine is used for feeding rubber material into the main runner 11 above the second injection molding station, then the rubber material flows into the sub-runners on the second fixed mold plate 200 in the main runner 11, and finally flows into the cavity between the second mold core 210 and the first mold cavity 120, meanwhile, the injection molding machine also feeds the rubber material into the main runner 11 above the first injection molding station, and the rubber material is enabled to fill the cavity between the first mold core 110 and the second mold cavity 220, so that the pre-molding layer B1 is processed in the first injection molding station, and the post-molding layer B2 is processed in the second injection molding station, and therefore the injection molding efficiency of the thick-wall lens is effectively shortened.

In the present embodiment, preferably, the first side plate 140 has two pieces and is disposed on two sides of the lower end of the first movable mold plate 130, and the second side plate 240 has two pieces and is disposed on two sides of the lower end of the second movable mold plate 20, so as to improve the stability of the first movable mold plate 130 and the second movable mold plate 230.

In this embodiment, it is preferable that the first movable platen 130 and the second movable platen 230 have guide cylinders 300 provided upward, the guide bars 400 respectively facing the guide cylinders 300 are provided at the bottoms of the first fixed platen 100 and the second fixed platen 200, and the guide cylinders 300 and the guide bars 400 are provided to improve the accuracy of clamping the injection mold.

In this embodiment, the first core 110, the first cavity 120, the second core 210, and the second cavity 220 all have a plurality of sets, and the injection mold further includes two hot runner plates respectively disposed between the fixed mold base plate 10 and the first fixed mold plate 100 and between the fixed mold base plate 10 and the second fixed mold plate 200, for uniformly and balancedly distributing the glue in the main runner 11 to the first runners 150 and the second runners 250.

Based on the volume that the preforming layer B1 is greater than the volume of back molding layer B2, therefore, when moulding plastics, the sizing material that flows to first injection molding station is more than the sizing material that flows to the second injection molding station, traditional mode of moulding plastics adopts two injection molding machines to carry out the pay-off respectively to two sprue 11, the cost has not only been increased, and because preforming layer B1, back molding layer B2 are not by the shaping of the sizing material in the same barrel, consequently, after the complete molding of thick wall lens, can influence its precision, consequently, at present adopt an injection molding machine mostly, carry out the pay-off through the mode of reposition of redundant personnel.

As shown in fig. 7 to 8, in the present embodiment, to achieve the diversion, a first injection channel 500 and a second injection channel 600 are respectively provided on the upper ports of the two main flow channels 11, and a regulator 700 for regulating the flow guide areas of the first injection channel 500 and the second injection channel 600 is provided in the first injection channel 500 and the second injection channel 600, wherein the regulator 700 includes:

a hollow valve body 710 having an inner cavity divided into a first cylindrical chamber 711 and a second cylindrical chamber 712, wherein an inner diameter of an inner port of the second chamber 712 is smaller than an inner diameter of an outer port thereof;

the adjusting head 720 is in a circular truncated cone shape and movably arranged in the second chamber 712 along the length direction of the valve body 710, and a gap between the adjusting head 720 and the second chamber 712 is used for allowing the rubber to flow from the first chamber 711 to the second chamber 712 and finally to flow to the main runner 11; when the adjusting head 720 moves towards the first cavity 711, the gap between the second cavity 712 and the adjusting head 720 is gradually reduced, and finally the outer wall of the adjusting head 720 abuts against the inner wall of the first cavity 711, so that the second cavity 712 is not communicated with the first cavity 711; as adjustment head 720 moves toward the outer port of second chamber 712, the gap between second chamber 712 and adjustment head 720 gradually increases, thereby increasing the outlet of first injection channel 500 or second injection channel 600.

In this embodiment, specifically, a connection plate 730 is disposed in an outer port of the second chamber 712, the connection plate 730 is fixed in the second chamber 712 through circumferentially distributed connection ribs 740, the connection plate 730 is provided with an adjustment rod 750 disposed along the direction of the first chamber 711, the adjustment head 720 is slidably disposed on the adjustment rod 750, the connection plate 730 is provided with a first electromagnet 760, the adjustment plug is further provided with a second electromagnet 770 opposite to the first electromagnet 760, the adjustment rod 750 is further provided with a buffer spring 780, one end of the buffer spring 780 abuts against the connection plate 730, the other end abuts against the adjustment head 720, and the adjuster 700 further includes a controller for adjusting the magnitude and direction of current passing through the first electromagnet 760 and the second electromagnet 770.

When the rubber compound is conveyed to the main channel 11, the controller controls the first electromagnet 760 and the second electromagnet 770 to generate attractive magnetic force, so that the adjusting head 720 approaches to the port of the second chamber 712 to communicate the first chamber 711 with the second chamber 712, the rubber compound required by the molding layer B1 is larger than the rubber compound required by the rear molding layer B2, in order to improve the feeding efficiency, the outlet of the first injection molding channel 500 and the outlet of the second injection molding channel 600 are proportionally adjusted to be larger or smaller, the feeding time of the first injection molding channel 500 and the feeding time of the second injection molding channel 600 are synchronized, namely, the first injection molding channel 500 and the second injection molding channel 600 are synchronously opened and closed, and after the feeding is finished, the controller controls the first electromagnet 760 and the second electromagnet 770 to generate repulsive magnetic force, so that the adjusting head 720 moves to the first chamber 711 and the second chamber 712 are gradually disconnected.

When the screw conveyor sends the molten rubber material to the injection gun, the flow rate of the rubber material entering the first injection molding channel 500 and the second injection molding channel 600 changes along with certain fluctuation, so that the fluctuation of the flow rate of the rubber material entering the main flow channel 11 also occurs, and after the regulator 700 is additionally arranged, the fluctuation can be counteracted under the action of the buffer spring 780. Specifically, when the pressure in the second injection molding channel 600 fluctuates upwards, the extrusion force applied to the buffer spring 780 is increased, so that the second injection molding channel is compressed, the adjusting head 720 moves towards the connecting plate 730, and when the second injection molding channel moves, the gap between the adjusting head 720 and the second cavity is increased, so that the rubber material flows to the main channel 11 smoothly; when fluctuating downwards, the pressure in the second injection molding channel 600 is reduced, and the extrusion force received by the buffer spring 780 is reduced, so that the adjusting head 720 is pushed, the adjusting head 720 moves towards the first cavity, and when moving, the gap between the adjusting head 720 and the second cavity is reduced, so that the rubber material flows to the main channel 11 stably.

Therefore, in this embodiment, the buffer spring 780 not only serves to buffer the adjusting head 720, but also can adjust the speed of the rubber material entering the main channel 11, so that the rubber material flowing through the main channel 11 can smoothly flow to the sub-channels.

While the embodiments of the present application have been described in connection with the drawings, the embodiments and features of the embodiments of the present application can be combined with each other without conflict, and the present application is not limited to the above-mentioned embodiments, which are only illustrative and not restrictive, and those skilled in the art can make many forms without departing from the spirit and scope of the present application and the claims.

Claims

1. A method for manufacturing a thick-walled lens comprises the steps of layering a thick-walled lens in the thickness direction thereof into a pre-molding layer (B1) and a post-molding layer (B2), and performing step injection molding; the end face of the pre-molded layer (B1) is an arc-shaped face protruding outwards, the end face of the rear molded layer (B2) is a plane, the layering face of the thick-wall lens is a concave-convex undulating face, and the area ratio of the cross section of the pre-molded layer (B1) to the area ratio of the cross section of the rear molded layer is 0.6-0.7.

2. A method for manufacturing a thick-walled lens as claimed in claim 1, wherein the rear molding layer (B2) has a symmetrical structure and is divided into a first portion (1), a second portion (2), a third portion (3) and a fourth portion (4) in sequence from the middle to the side end; the thick-walled lens has a maximum thickness of H, a thickness of H1 in the first portion (1), a thickness of H2 in the second portion (2), a thickness of H3 in the third portion (3), and a thickness of H4 in the fourth portion (4);

3. A method of making a thick-walled lens as claimed in claim 2, wherein the diameter of the thick-walled lens is L, the length of the first portion (1) is L1, the length of the second portion (2) is L2, the length of the third portion (3) is L3, and the length of the fourth portion (4) is L4;

wherein, L1, L is 0.01; l2, L is 0.05; l3, L is 0.07; l4: l is 0.15; the first part (1) is connected with the second part (2), the second part (2) is connected with the third part (3), and the third part (3) is connected with the fourth part (4) by inclined planes.

4. An injection mold for use in the method of manufacturing a thick-walled lens as claimed in any one of claims 1 to 3, comprising a first injection station for forming the pre-form layer (B1); and a second injection molding station for molding the post-molding layer (B2); after the pre-formed layer (B1) is cooled and formed, the pre-formed layer (B1) on the first injection molding station is rotated to the second injection molding station by a rotating device for secondary forming.

5. An injection mould according to claim 4, characterized in that it further comprises:

the injection gun fixing structure comprises a fixed mold base plate (10), wherein a main flow channel (11) penetrates through the fixed mold base plate (10), a positioning ring for positioning an injection gun is arranged on the main flow channel (11), and two main flow channels (11) are symmetrically arranged on the fixed mold base plate (10);

and a movable mold base plate (20);

the first injection molding station sequentially comprises a first fixed mold plate (100), a first mold core (110), a first cavity (120), a first movable mold plate (130) and a first side plate (140) from top to bottom; the first fixed die plate (100) is arranged below the fixed die base plate (10), the first core (110) is arranged at the lower end of the first fixed die plate (100), the first fixed die plate (100) is further provided with a first branch runner (150) of which the upper end is communicated with one of the main runners (11) and the lower end is communicated with the first core (110), the first cavity (120) is arranged on the first movable die plate (130) and is opposite to the first core (110), after die assembly, a cavity for forming a pre-forming layer (B1) is formed in a space between the first core (110) and the first cavity (120), the lower end of the first side plate (140) is arranged on the movable die base plate (20), and the upper end of the first side plate is connected with the first movable die plate (130);

the second injection molding station sequentially comprises a second fixed mold plate (200), a second mold core (210), a second mold cavity (220), a second movable mold plate (230) and a second side plate (240) from top to bottom; the second fixed die plate (200) is arranged below the fixed die base plate (10), the second core (210) is arranged at the lower end of the second fixed die plate (200), the second fixed die plate (200) is also provided with a second branch runner (250) of which the upper end is communicated with the other main runner (11) and the lower end is communicated with the second core (210), the second cavity (220) is arranged on the second movable die plate (230) and is opposite to the second core (210), after die assembly, a cavity of a molded layer (B2) is formed in a space between the second core (210) and the second cavity (220), the lower end of the second side plate (240) is arranged on the movable die base plate (20), and the upper end of the second side plate is connected with the second movable die plate (230);

after the pre-molded layer (B1) is cooled and molded, opening the mold is performed, the first cavity (120) is separated from the first core (110), the second cavity (220) is separated from the second core (210), then the movable mold base plate (20) is driven by a rotating device to rotate 180 degrees, the first cavity (120) is opposite to the second core (210), and the second cavity (220) is opposite to the first core (110).

6. An injection mold according to claim 5, wherein said first side plate (140) has two pieces and is disposed on both sides of a lower end of said first movable mold plate (130), respectively, and said second side plate (240) has two pieces and is disposed on both sides of a lower end of said second movable mold base plate (20), respectively.

7. An injection mold according to claim 5, wherein the first movable mold plate (130) and the second movable mold plate (230) are provided with guide cylinders (300) which are arranged upwards, and the bottoms of the first fixed mold plate (100) and the second fixed mold plate (200) are provided with guide rods (400) which are respectively opposite to the guide grooves (300).