Optical lens with latent glue injection mold

Abstract

The application discloses an optical lens hidden glue type injection mold, which comprises a back mold core, a cavity group is arranged on the back mold core, the cavity group comprises a cavity, a hot nozzle glue inlet and a glue inlet runner, the glue inlet runner comprises a main runner and a branch runner, a square back mold insert is inlaid at a joint of each branch runner and the cavity, the cavity comprises a large cavity part and a small cavity part, the small cavity part is arranged on the back mold insert, a tapered hidden glue inlet which gradually reduces towards the cavity is arranged on an inner side wall of the small cavity part, a connecting runner is smoothly connected to a large end of the tapered hidden glue inlet through a circular arc, and the connecting runner is smoothly connected with the branch runner. The square large glue inlet is changed into the tapered hidden glue inlet in the application, the product and the nozzle material are automatically disconnected when the product is ejected through the ejector pin device after injection molding, and the product directly falls into the lower material box, so that the process flow of the mechanical hand suction and laser cutting is saved, the production cycle is shortened, and the production efficiency is greatly improved. Meanwhile, the number of cavity holes on the mold can be increased, and the production capacity is increased by more than 40%.

Description

A type of latent injection mold for optical lenses Technical Field

[0001] This invention relates to the field of optical lens manufacturing technology, and in particular to a submerged injection mold for optical lenses. Background Technology

[0002] Optical lenses are one of the fundamental optical components in optics and optoelectronics. They are widely used in LED lighting, chip manufacturing, super-resolution science, and many other high-tech products.

[0003] Currently, the injection molding process for optical lenses involves: 1. Injection molding; 2. Using a robotic arm to transfer the molded part to a laser cutting machine; 3. Laser cutting; 4. Using a robotic arm to transfer the product into a product box and to transfer the sprue material into a sprue box. Because the existing injection molds for optical lenses have a large, square sprue between the runner and the cavity, the lens and sprue material remain connected after injection molding, preventing direct unloading. The process requires a robotic arm to transfer the part, laser cutting, and then another robotic arm to remove the sprue material. This is inefficient, time-consuming, and increases the energy consumption and maintenance costs of the robotic arm and laser cutting machine. Summary of the Invention

[0004] To address the problems of low production efficiency, long cycle time, and increased energy consumption in existing optical lens injection molding processes where material cannot be directly unloaded after injection molding and requires a robotic arm to pick up the plastic part for laser cutting and then unloading, this invention provides a submerged injection mold for optical lenses. It replaces the existing large square nozzle with a conical submerged nozzle. After injection molding, the product is automatically separated from the sprue material by an ejector pin device and falls directly into the material bin below. This eliminates the need for robotic arm pickup and laser cutting, shortens the production cycle, significantly improves production efficiency, and saves energy and maintenance costs associated with robotic arms and laser cutting machines.

[0005] To achieve the above objectives, the present invention provides a submerged injection mold for optical lenses, comprising a rear mold plate, wherein the rear mold plate has a plurality of rear mold cores evenly distributed in an array, and the rear mold cores have a cavity assembly, the cavity assembly including cavities, hot runner inlets, and injection channels. The hot runner inlet is located at the center of the rear mold core, and there are 2N cavities evenly distributed in a ring array around the hot runner inlet, where N is a natural number greater than 1. The injection channels include main channels and branch channels. The main channels are connected to the hot runner inlet, and there are N main channels evenly distributed in a circumferential array. Each main channel has two branch channels symmetrically distributed relative to the main channel at its end. The branch channels are connected to corresponding cavities, and the two cavities corresponding to the end of each main channel are symmetrically distributed. The invention is characterized in that: at the connection between each branch channel and the cavity... The mold includes a square rear mold insert and a cavity comprising a large cavity and a small cavity. The large cavity is located on the rear mold core, and the small cavity is located on the rear mold insert. The inner wall of the small cavity has a tapered submersible orifice that gradually narrows towards the cavity. The large end of the tapered submersible orifice is smoothly connected to a connecting runner via an arc. The connecting runner is smoothly connected to the branch runner. The cavity has a first ejector hole in the center and three second ejector holes evenly distributed in a circle around its perimeter. One second ejector hole is located in the center of the small cavity. A third ejector hole is located at the connection between the two branch runners and the main runner. The first, second, and third ejector holes are respectively equipped with a first ejector pin, a second ejector pin, and a third ejector pin. The first, second, and third ejector pins are all connected to an ejection device located behind the rear mold core for ejecting and unloading the optical lens after injection molding.

[0006] As a further improvement to this technology, the angle α between the central axis of the conical submersible nozzle and the vertical line is set to 42±10°, and the taper of the conical submersible nozzle is set to 20±10°.

[0007] As a further improvement to this technology, the maximum diameter of the small end of the tapered submerged nozzle is ≤0.9mm.

[0008] As a further improvement to this technology, the lower end of the rear mold insert is provided with a stepped portion extending outward and downward, and the lower end of the rear mold core is provided with a square countersunk hole corresponding to the stepped portion for engagement and attachment. The bottom surface of the stepped portion is engaged and connected with the square countersunk hole, which facilitates later maintenance and replacement.

[0009] As a further improvement to this technology, the rear mold insert is made of SKD61 hardened mold steel, which is quenched and the quenching hardness is set to HRC48-52. The conical submerged rubber inlet is polished and the surface finish reaches level 7 or above.

[0010] As a further improvement to this technology, the number of cavities in the submerged injection mold is increased by 10-30% compared to the number of cavities in existing molds under the same injection molding equipment conditions.

[0011] Compared with the prior art, the beneficial effects of this invention are as follows: 1. This invention changes the existing large square gate to a conical submerged gate. After injection molding, when the product is ejected by the ejector device, the product and the sprue material will automatically separate and fall directly into the material box below, thereby saving the process of robotic arm suction and laser cutting, shortening the production cycle, greatly improving production efficiency, and saving energy consumption and maintenance costs of robotic arms and laser cutting machines; 2. After the mold is changed to a submerged type, the number of cavities in the mold is no longer limited by robotic arms and laser cutting machines. The mold can be enlarged, and the number of cavities on the mold can be increased, so that the production capacity of an existing injection molding machine can be increased by more than 40%; 3. This invention sets the conical submerged gate on the rear mold insert. The rear mold insert is connected to the rear mold core through the stepped part, so that the rear mold insert can be replaced individually after wear, which can greatly improve the maintenance efficiency and maintenance cost of the rear mold core. Attached Figure Description

[0012] Figure 1 is a schematic diagram of the existing rear mold core structure;

[0013] Figure 2 is a schematic diagram of the rear mold core structure according to an embodiment of the present invention;

[0014] Figure 3 is a schematic diagram of the main view structure of the rear mold core according to an embodiment of the present invention.

[0015] Figure 4 is a cross-sectional view of AA in Figure 3;

[0016] Figure 5 is a schematic diagram of the rear mold insert structure according to an embodiment of the present invention.

[0017] Figure 6 is a top view of the rear mold insert structure according to an embodiment of the present invention.

[0018] Figure 7 is a cross-sectional view of BB in Figure 6.

[0019] In the diagram: 1. Rear mold core, 101. Square countersunk hole, 2. Cavity, 2-1. Large cavity, 2-2. Small cavity, 3. Hot runner inlet, 4. Main runner, 5. Sub-runner, 6. Rear mold insert, 601. Conical sub-gate, 602. Stepped section, 603. Connecting runner, 6'. Large gate, 7. First ejector pin hole, 8. Second ejector pin hole, 9. Third ejector pin hole. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] As shown in Figures 2 to 7, Embodiment 1 of the present invention includes a rear mold plate, on which 32 rear mold cores 1 are arranged in an array. Each rear mold core 1 has a cavity assembly, which includes cavities 2, hot runner inlets 3, and flow channels. The hot runner inlets 3 are located at the center of the rear mold core 1. There are 20 cavities 2 arranged in a ring array around the hot runner inlets 3. The flow channels include main channels 4 and branch channels 5. The main channels 4 are connected to the hot runner inlets 3. There are 10 main channels 4 arranged in a circumferential array, and each main channel 4 has two branch channels 5 symmetrically distributed relative to it at its end. Each branch channel 5 is connected to a corresponding cavity 2. The two cavities 2 at the end of each main channel 4 are symmetrically distributed relative to it. A square rear mold insert 6 is embedded at the connection between each branch channel 5 and the cavity 2. Each cavity 2 includes a large cavity 2-1 and a small cavity. Part 2-2, the large cavity 201 is located on the rear mold core 1, and the small cavity 2-2 is located on the rear mold insert 6. The inner wall of the small cavity 2-2 is provided with a tapered submersible vent 601 that gradually narrows towards the cavity 2. The large end of the tapered submersible vent 601 is smoothly connected to the connecting flow channel 603 by a circular arc. The connecting flow channel 603 is smoothly connected to the branch flow channel 5. The cavity 2 is provided with a first ejector hole 7 in the middle and three second ejector holes 8 evenly distributed in a circle around the periphery. One second ejector hole 8 is located in the middle of the small cavity 2-2. A third ejector hole 9 is provided at the connection between the two branch flow channels 5 and the main flow channel 4. The first ejector hole 7, the second ejector hole 8 and the third ejector hole 9 are respectively provided with a first ejector, a second ejector and a third ejector. The first ejector, the second ejector and the third ejector are all connected to the ejection device located behind the rear mold core 1, and are used to eject and unload the optical lens after injection molding.

[0023] In this embodiment of the invention, the existing square large sprue 6' (see Figure 1) is changed to a conical submerged sprue 601. After injection molding, when the product is ejected by the ejector device, the product and the sprue material will automatically separate and fall directly into the material box below. This saves the process of robotic arm picking up and laser cutting, shortens the production cycle, greatly improves production efficiency, and saves energy consumption and maintenance costs of robotic arms and laser cutting machines.

[0024] As shown in Figure 7, the angle α between the central axis of the conical submersible nozzle 601 and the vertical line is set to 42°, and the taper β of the conical submersible nozzle 601 is set to 20°.

[0025] The maximum diameter of the small end of the tapered submersible nozzle 601 is 0.86 mm.

[0026] As shown in Figures 4 and 7, the lower end of the rear mold insert 6 has a stepped portion 602 extending outward and downward. The lower end of the rear mold core 1 has a square countersunk hole 101 that engages and attaches with the stepped portion 602. The bottom surface of the stepped portion 602 and the square countersunk hole 101 are connected and attached, facilitating future maintenance and replacement. This allows the rear mold insert to be replaced individually after wear, greatly improving the maintenance efficiency and reducing the maintenance cost of the rear mold core 1.

[0027] The rear mold insert 6 is made of SKD61 hardened mold steel, which has been quenched to a hardness of HRC48-52. The tapered submerged nozzle is polished to a finish of grade 7 or higher.

[0028] In Embodiment 1 of the present invention, the rear template has 32×20=640 cavities.

[0029] In Embodiment 1 of this invention, 640 optical lenses can be injection molded in one mold. Because the robotic arm suction and laser cutting processes are eliminated, the production cycle is reduced from 50 seconds to 40 seconds. Assuming a yield rate of 90%, the daily production capacity of optical lenses is 1.24 million. Under the same injection molding equipment conditions as Embodiment 1, existing large-cavity injection molds can have a maximum of 512 cavities, allowing for the injection molding of 512 optical lenses in one mold. With a production cycle of 50 seconds and a yield rate of 90%, the daily production capacity of optical lenses is 800,000. Therefore, Embodiment 1 of this invention increases the production capacity by 55% compared to existing technologies.

[0030] The second embodiment of the present invention is basically the same as the first embodiment, except that the rear template is provided with 27 rear mold cores 1 arranged in an array, the rear mold core 1 has 16 cavities 2, the main channel has 8 channels, and the rear mold insert 6 has 16 pieces.

[0031] In Embodiment 2 of the present invention, the mold has a total of 27 × 16 = 432 cavities, allowing for the injection molding of 432 optical lenses in one mold. Because the robotic arm and laser cutting processes are eliminated, the production cycle is reduced from 50 seconds to 40 seconds. Assuming a 90% yield rate, the daily production capacity of optical lenses is 840,000. Under the same injection molding equipment conditions as Embodiment 1 of the present invention, existing injection molds can have a maximum of 384 cavities, allowing for the injection molding of 384 optical lenses in one mold. The production cycle is 50 seconds, and with a 90% yield rate, the daily production capacity of optical lenses is 600,000. Therefore, Embodiment 2 of the present invention increases the production capacity by 40% compared to existing technologies.

[0032] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several improvements and substitutions without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A submerged injection mold for an optical lens, comprising a rear mold plate, wherein the rear mold plate has a plurality of rear mold cores evenly distributed in an array, the rear mold cores having a cavity assembly, the cavity assembly including cavities, hot runner inlets and flow channels, the hot runner inlets being located at the center of the rear mold cores, the cavities having 2N cavities evenly distributed in a ring array around the hot runner inlets, wherein N is a natural number greater than 1, the flow channels including main channels and branch channels, the main channels communicating with the hot runner inlets, the main channels having N main channels evenly distributed in a circumferential array, and each main channel having two branch channels symmetrically distributed relative to the main channel at its end, the branch channels communicating with corresponding cavities, the two cavities corresponding to the end of each main channel being symmetrically distributed, characterized in that: Each of the aforementioned runners is fitted with a square rear mold insert at the connection point with the cavity. The cavity includes a large cavity and a small cavity. The large cavity is located on the rear mold core, and the small cavity is located on the rear mold insert. The inner wall of the small cavity has a tapered submersible orifice that gradually narrows towards the cavity. The large end of the tapered submersible orifice is smoothly connected to a connecting runner via an arc. The connecting runner is smoothly connected to the runner. A first ejector hole is located in the center of the cavity, and three second ejector holes are evenly distributed around its perimeter. One of the second ejector holes is located in the center of the small cavity. A second ejector hole is located at the connection point between the two runners and the main runner. The three ejector holes are respectively equipped with a first ejector pin, a second ejector pin, and a third ejector pin. The first, second, and third ejector pins are all connected to an ejection device located behind the rear mold core, used to eject and unload the optical lens after injection molding. The maximum diameter of the small end of the tapered submerged nozzle is ≤0.9mm. The lower end of the rear mold insert is provided with a stepped portion extending outward and downward. The lower end of the rear mold core and the corresponding position of the stepped portion are provided with square countersunk holes for engagement and attachment. The bottom surface of the stepped portion and the square countersunk holes are engaged and connected for easy maintenance and replacement in the future.

2. The optical lens latent injection mold according to claim 1, characterized in that: The angle α between the central axis of the conical submersible nozzle and the vertical line is set to 42±10°, and the taper of the conical submersible nozzle is set to 20±10°.

3. The optical lens latent injection mold according to claim 1, characterized in that: The rear mold insert is made of SKD61 hardened mold steel, which has been quenched to a hardness of HRC48-52. The tapered submerged nozzle is polished to a surface finish of grade 7 or higher.

4. The optical lens latent injection mold according to claim 1, characterized in that: The number of cavities in the aforementioned submerged injection mold is 10-30% higher than that in existing molds under the same injection molding equipment conditions.

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