A mold for two-color injection molding of an optical lens and an injection molding method thereof

Abstract

The present application relates to a kind of two-color injection molding optical lens mold and its injection molding method, belong to injection molding technical field, comprising: movable mould, fixed mould, rotary compensation component, rotary compensation component is connected to the end of fixed mould away from movable mould, the end of rotary compensation component away from fixed mould is connected with the rotary table of two-color injection molding machine;Laser displacement sensor, is connected to the side of movable mould;Mirror, is connected to the side of rotary compensation component towards laser displacement sensor;When rotary table rotates, laser displacement sensor receives the light signal reflected by mirror, rotary compensation component is compensated rotation according to the deviation of light signal reception;It can solve the technical problems that reverse gap and gap after wear exist in the transmission mode of gear rack in the prior art, when reciprocating rotation is carried out, it will lead to that positioning accuracy is difficult to meet the two-color injection molding of optical lens.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of injection molding, and particularly relates to a mold for double-color injection molding of an optical lens and an injection molding method thereof. BACKGROUND

[0002] The double-color injection mold is often used in combination with a double-color injection molding machine. The mold is opened and closed and material is fed by a movable mold connected with a hot melt assembly. A rotating disc on the injection molding machine completes 180-degree rotation of a fixed mold to meet the injection of two different materials into a cavity. Because the injection of two different materials is performed twice, the double-color injection molding of the optical lens requires high positioning accuracy of the fixed mold.

[0003] The existing patent with the publication number CN219095727U discloses a positioning mechanism for a mold mounting disc of a double-color injection molding machine. The injection mold is mounted on the mounting disc by bolts. The mounting disc is connected with a connecting rod A through a bearing. The connecting rod A is mounted on a connecting plate B. A rack is mounted on the mounting disc. The rack is engaged with a gear A. The gear A is engaged with a gear B. The gear B is connected with a motor. A positioning rod is mounted on the mounting disc. The positioning rod is clamped in a positioning groove in the connecting plate B. A buffer mechanism is mounted in the positioning groove.

[0004] The existing technology has the following problems:

[0005] The transmission mode of the rack and pinion gear has reverse clearance and clearance after wear. When reciprocating rotation is performed, the positioning accuracy is difficult to meet the double-color injection molding of the optical lens. SUMMARY

[0006] The application provides a mold for double-color injection molding of an optical lens and an injection molding method thereof, which can solve the technical problem that the transmission mode of the rack and pinion gear has reverse clearance and clearance after wear. When reciprocating rotation is performed, the positioning accuracy is difficult to meet the double-color injection molding of the optical lens.

[0007] To achieve the above-mentioned purpose, the application realizes the following technical scheme:

[0008] The application provides a mold for double-color injection molding of an optical lens, which comprises a movable mold and a fixed mold and further comprises:

[0009] A rotation compensation assembly is connected to one end of the fixed mold away from the movable mold. One end of the rotation compensation assembly away from the fixed mold is connected with a rotating table of a double-color injection molding machine.

[0010] A laser displacement sensor is connected to the side surface of the movable mold.

[0011] A mirror is connected to one side of the rotation compensation assembly facing the laser displacement sensor.

[0012] When the rotary table rotates, the laser displacement sensor receives the light signal reflected by the mirror, and the rotation compensation assembly compensates for the rotation according to the deviation of the light signal received.

[0013] By the above technical solution, the laser displacement sensor and the rotation compensation assembly are used to directly compensate for the rotation repeatability positioning deviation of the rotary table of the two-color injection molding machine, reduce the influence of the reverse clearance and wear of the mechanical transmission components on the repeatability positioning accuracy, and make the positioning accuracy of the two-color injection mold meet the two-color injection molding demand of the optical lens.

[0014] In the present application, the above-mentioned mold further comprises:

[0015] A semiconductor refrigeration sheet has a cold face and a hot face, the cold face faces the laser displacement sensor, and the hot face abuts against the moving die.

[0016] By the above technical solution, the semiconductor refrigeration sheet is used to reduce the interference of the heat generated during mold injection on the laser displacement sensor, and improve the measurement accuracy.

[0017] In the present application, the above-mentioned rotation compensation assembly comprises:

[0018] A mounting seat is used to connect the rotary table;

[0019] A rotating seat is rotationally connected with the mounting seat, and the rotating seat is connected with the fixed die;

[0020] A servo motor is connected in the mounting seat, the servo motor directly drives the rotating seat to rotate, and the servo motor is communicatively connected with the laser displacement sensor.

[0021] By the above technical solution, the rotating seat in the rotation compensation assembly is directly driven by the servo motor, further reducing the existence of mechanical transmission, improving the motion accuracy, and being more convenient for realizing fine adjustment of the rotation angle.

[0022] In the present application, the above-mentioned rotation compensation assembly comprises:

[0023] A telescopic cylinder is connected in the mounting seat;

[0024] A friction block is connected to one end of the telescopic cylinder away from the mounting seat;

[0025] A friction plate is connected to one side of the rotating seat facing the mounting seat, and when the telescopic cylinder is elongated, the friction block abuts against the friction plate.

[0026] By the technical scheme, the telescopic cylinder is used to realize the active brake, and the positioning capability of the rotating seat is enhanced.

[0027] In the application, the rotating compensation assembly comprises:

[0028] An electronic level is connected to the horizontal plane of the rotating seat, and the electronic level is in communication connection with the servo motor.

[0029] By the technical scheme, the electronic level is further used to obtain the rotation angle deviation of the rotating seat, and the laser displacement sensor is used for double verification, so that the positioning precision of the repeated positioning is further improved.

[0030] The application provides another injection molding method of the bicolored injection molded optical lens, which uses the mold of the bicolored injection molded optical lens and further comprises the following steps:

[0031] Step S10: install the mold to the bicolored injection molding machine, and complete the first injection of the first cavity;

[0032] Step S20: separate the movable mold from the fixed mold, and rotate the rotating table of the bicolored injection molding machine by 180 degrees;

[0033] Step S30: the laser displacement sensor obtains the offset amount of the reflected laser signal, and the servo motor is started to drive the rotating seat to rotate until the reflected laser signal obtained by the laser displacement sensor has no offset amount;

[0034] Step S40: the movable mold is combined with the fixed mold, and the second injection of the first cavity and the first injection of the second cavity are completed.

[0035] By the technical scheme, the offset amount is compensated before the mold is combined, so that the positional offset between the first injection and the second injection is avoided, and the yield is improved.

[0036] In the application, the first injection of the first cavity completed in the step S10 is the structure part of the optical lens, and the second injection of the first cavity completed in the step S40 is the optical part of the optical lens.

[0037] By the technical scheme, the structure part is first injected, and then the optical part is injected, so that the influence of the second injection on the first injection is reduced, and the injection quality of the optical part is improved.

[0038] The application has the following beneficial effects:

[0039] 1. The laser displacement sensor and the rotating compensation assembly are used to directly compensate the rotation repeated positioning deviation of the rotating table of the bicolored injection molding machine, the influence of the reverse gap and wear of the mechanical transmission component on the repeated positioning precision is reduced, the positioning precision of the bicolored injection mold meets the bicolored injection molding demand of the optical lens, and the yield is improved.

[0040] 2, offset compensation is carried out before mold closing, position offset between primary injection and secondary injection is avoided, and the yield is improved. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0042] Figure 1 An isometric view of a mold for a two-color injection-molded optical lens is provided for the embodiments of the present application.

[0043] Figure 2 An isometric view of a mold for a two-color injection-molded optical lens is provided for the embodiments of the present application, removing the moving mold and the fixed mold.

[0044] Figure 3 An isometric view of a mold for a two-color injection-molded optical lens is provided for the embodiments of the present application, removing the moving mold and the fixed mold.

[0045] Figure 4 An isometric view of a mold for a two-color injection-molded optical lens is provided for the embodiments of the present application, removing the moving mold and the fixed mold. Figure 3 An isometric view of a mold for a two-color injection-molded optical lens is provided for the embodiments of the present application, removing the moving mold and the fixed mold.

[0046] Figure 5 An isometric view of a mold for a two-color injection-molded optical lens is provided for the embodiments of the present application, removing the moving mold and the fixed mold. Figure 3 An isometric view of a mold for a two-color injection-molded optical lens is provided for the embodiments of the present application, removing the moving mold and the fixed mold.

[0047] Figure 6 An isometric view of a mold for a two-color injection-molded optical lens is provided for the embodiments of the present application, removing the moving mold and the fixed mold.

[0048] Figure legend: 1-rotation compensation assembly; 101-mounting seat; 1011-threading groove; 1012-quick positioning pin hole; 102-rotation seat; 1022-stiffener; 1023-mounting boss; 103-servo motor; 104-telescopic cylinder; 105-friction block; 106-friction plate; 107-electronic level; 2-fixed mold; 3-moving mold; 401-laser displacement sensor; 402-reflector; 403-semiconductor refrigeration piece; 404-bracket. DETAILED DESCRIPTION

[0049] The embodiments of the present application will be described in detail below with reference to the drawings.

[0050] In the description of the present application, it needs to be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0051] The terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0052] In the description of the present application, it needs to be explained that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be welding, or bolted connection, or riveting; it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0053] Embodiment:

[0054] Please refer to Figures 1 to 6 , Figures 1 to 6 The figure shows an embodiment of the present application.

[0055] The embodiment provides a mold for double-color injection molding optical lens, comprising a movable mold 3 and a fixed mold 2, further comprising:

[0056] A rotation compensation assembly 1 is connected to one end of the fixed mold 2 away from the movable mold 3, and the end of the rotation compensation assembly 1 away from the fixed mold 2 is connected to the rotating table of a double-color injection molding machine (exemplarily adopting Haitian IA-II series multi-component injection molding machine);

[0057] A laser displacement sensor 401 is connected to the side of the movable mold 3;

[0058] A mirror 402 is connected to one side of the rotation compensation assembly 1 facing the laser displacement sensor 401;

[0059] When the rotating table rotates and the laser displacement sensor 401 receives the light signal reflected by the mirror 402, the rotation compensation assembly 1 compensates for the rotation according to the deviation amount of the light signal received.

[0060] In use, the laser emitter: select the wavelength of 650nm semiconductor laser (exemplary selected ROITHNER LDA series), output power 5-10mW to balance the accuracy and safety, need to configure collimating lens to control the divergence angle within 0.5mrad, to ensure the stability of the spot on the receiver.

[0061] The receiver design: using a one-dimensional linear CCD sensor or position sensitive detector.

[0062] Scale calibration: in the receiver surface integration high-precision scale, through the optical magnification system will be converted into a spot displacement grating fringe movement, combined with moire fringe counting method can realize nanometer resolution.

[0063] Need to explain, the moving die 3 and the fixed die 2 are the prior art according to the conventional setting of specific products, and the specific structure does not belong to the protection scope of the application.

[0064] Through the above technical scheme, the laser displacement sensor 401 and the rotation compensation assembly 1 are adopted to directly compensate the rotation repeat positioning deviation of the rotating table of the double-color injection molding machine, the influence of the reverse gap and wear of the mechanical transmission component on the repeat positioning accuracy is reduced, the positioning accuracy of the double-color injection mold meets the double-color injection molding demand of the optical lens.

[0065] As a better implementation, the above mold further comprises:

[0066] The semiconductor refrigeration sheet 403 has a cold face and a hot face, and the cold face faces the laser displacement sensor 401. Figure 2 As shown in the figures, the cold face is in abutment with the bracket 404, and the bracket 404 is used to connect the semiconductor refrigeration sheet 403. Figure 6 The hot face is in abutment with the moving die 3 under the pressing of the bracket 404.

[0067] It should be noted that the temperature of the cold face of the semiconductor refrigeration sheet 403 is not less than 0 degrees Celsius, so as to avoid the influence of low temperature on the normal work of the laser displacement sensor 401, and the hot face is selected to be in abutment with the outside of the heating runner, and the heat is dissipated through the medium in the runner, so as to fully utilize the preheating to preheat and keep warm the cavity.

[0068] Through the above technical scheme, the semiconductor refrigeration sheet 403 is adopted to reduce the interference of the heat generated during the injection molding of the mold on the laser displacement sensor 401, and the measurement accuracy is improved.

[0069] As a better implementation, the above rotation compensation assembly 1 comprises:

[0070] The mounting seat 101 is used to connect the rotating table. Figure 3 As shown in the figures, the mounting seat 101 is used to connect the rotating table. Figure 6As shown, the mounting seat 101 is provided with four waist-shaped holes for fastening screws and connecting the rotating table of the injection molding machine, and two quick positioning pin holes 1012 for quick positioning on the rotating table;

[0071] The rotating seat 102 is rotationally connected with the mounting seat 101, the rotating seat 102 is connected with the fixed mold 2, and the side of the rotating seat 102 facing the mounting seat 101 is hollowed out and provided with a reinforcing rib 1022;

[0072] The servo motor 103 (for example, a Delta MST series servo motor, model MST-SR617FXB0D, which has a relatively flat body and a relatively large load capacity) is connected in the mounting seat 101, the servo motor 103 directly drives the rotating seat 102 to rotate, the servo motor 103 is in communication connection with the laser displacement sensor 401, and a STM32F4 series single-chip microcomputer with a hardware PID is used, and the 16-bit PWM channel can directly drive the servo motor 103, such as Figure 2 and Figure 3 As shown, the rotating shaft of the servo motor 103 is directly connected with the rotating seat 102 by five screws.

[0073] It should be noted that the specific hardware and software settings of the photoelectric signal to the control signal can be set by textbooks, technical manuals and technical dictionaries by those skilled in the art, and the specific setting does not belong to the protection scope of the present application, any setting that can meet the related control ability can be used, therefore, it is not further explained and specifically limited here.

[0074] Through the above technical scheme, the rotating seat 102 in the rotating compensation assembly 1 is directly driven by the servo motor 103, further reducing the existence of mechanical transmission, improving the motion accuracy, and being more convenient to realize the fine adjustment of the rotation angle.

[0075] As a relatively optimal implementation manner, the rotating compensation assembly 1 comprises:

[0076] The telescopic cylinder 104 is connected in the mounting seat 101, the telescopic cylinder 104 is specifically driven by hydraulic pressure, and is controlled and driven by an external hydraulic circuit and a hydraulic source, and the hydraulic circuit and the circuit of the servo motor 103 are wired through the wire slot 1011 formed on the back of the mounting seat 101;

[0077] The friction block 105 is connected to one end of the telescopic cylinder 104 away from the mounting seat 101;

[0078] The friction plate 106 is connected to one side of the rotating seat 102 facing the mounting seat 101, and specifically as Figure 5 As shown, the rotating seat 102 is provided with a mounting boss 1023 for mounting the friction plate 106, and when the telescopic cylinder 104 is elongated, the friction block 105 abuts against the friction plate 106.

[0079] It should be noted that the hydraulic control circuit, hydraulic source and the like are conventional basic matching settings for injection molding, which are not within the protection scope of the present application. The circuit, power source, air circuit, liquid circuit and the like in the present application are directly input through pipelines by using the existing power source of the factory.

[0080] Through the above technical solution, the telescopic cylinder 104 is used to realize the active brake, and the positioning ability of the rotating seat 102 is enhanced.

[0081] As a more preferred embodiment, the above rotating compensation assembly 1 comprises:

[0082] The electronic level 107 is connected to the horizontal plane of the rotating seat 102, and the electronic level 107 is in communication connection with the servo motor 103.

[0083] Through the above technical solution, the electronic level 107 is further used to obtain the rotation angle deviation of the rotating seat 102, and the laser displacement sensor 401 is used for double verification, so that the positioning accuracy is further improved.

[0084] The embodiment also provides an injection molding method of the bicolored injection molded optical lens, which uses the mold of the bicolored injection molded optical lens and further comprises the following steps:

[0085] Step S10: installing the mold to the bicolored injection molding machine and completing the first injection of the first cavity;

[0086] Step S20: separating the movable mold 3 from the fixed mold 2, and rotating the rotating table of the bicolored injection molding machine by 180 degrees;

[0087] Step S30: the laser displacement sensor 401 obtains the offset amount of the reflected laser signal through the reflector 402, and the servo motor 103 is started to drive the rotating seat 102 to rotate until the laser displacement sensor 401 obtains no offset amount of the reflected laser signal;

[0088] Step S40: the movable mold 3 is combined with the fixed mold 2, and the second injection of the first cavity and the first injection of the second cavity are completed.

[0089] Through the above technical solution, the offset amount is compensated before the mold is combined, so that the position offset between the first injection and the second injection is avoided, and the yield is improved.

[0090] As a more preferred embodiment, the first injection of the first cavity completed in the step S10 is the structure part of the optical lens, wherein the structure part is made of PC material, the second injection of the first cavity completed in the step S40 is the optical part of the optical lens, wherein the optical part is made of PMMA material, and the melting point of the PMMA material is lower than that of the PC material. Therefore, the PC material is not easy to melt during the second injection.

[0091] By the technical scheme, the structure part is first injected, and then the optical part is injected, so that the influence of the secondary injection on the primary injection is reduced, and the injection quality of the optical part is improved.

[0092] The above merely provides a specific implementation of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical scope of the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A mold for two-color injection molding an optical lens comprising a movable mold (3) and a fixed mold (2) characterized in that, Also comprising: a rotation compensation assembly (1) connected to one end of the fixed mold (2) away from the movable mold (3), one end of the rotation compensation assembly (1) away from the fixed mold (2) is connected to the rotating table of the two-color injection molding machine; a laser displacement sensor (401) connected to the side of the movable mold (3); a mirror (402) connected to one side of the rotation compensation assembly (1) facing the laser displacement sensor (401); When the rotating table rotates, the laser displacement sensor (401) receives the light signal reflected by the mirror (402), and the rotation compensation assembly (1) compensates for the rotation according to the deviation of the light signal received; The rotation compensation assembly (1) comprises: a mounting seat (101) for connecting the rotating table; a rotating seat (102) rotationally connected to the mounting seat (101), the rotating seat (102) is connected to the fixed mold (2); a servo motor (103) connected in the mounting seat (101), the servo motor (103) directly drives the rotating seat (102) to rotate, and the servo motor (103) is in communication connection with the laser displacement sensor (401).

2. The mold for a two-color injection-molded optical lens according to claim 1, characterized by, Also comprising: a semiconductor refrigeration sheet (403) having a cold face and a hot face, the cold face facing the laser displacement sensor (401), and the hot face abutting against the movable mold (3).

3. The mold for two-color injection molding of an optical lens according to claim 2, characterized in that, The rotation compensation assembly (1) comprises: a telescopic cylinder (104) connected in the mounting seat (101); a friction block (105) connected to one end of the telescopic cylinder (104) away from the mounting seat (101); a friction plate (106) connected to one side of the rotating seat (102) facing the mounting seat (101), when the telescopic cylinder (104) is elongated, the friction block (105) abuts against the friction plate (106).

4. The mold for two-color injection molding of an optical lens according to claim 3, characterized by The rotation compensation assembly (1) comprises: an electronic level (107) connected to the horizontal surface of the rotating seat (102), the electronic level (107) is in communication connection with the servo motor (103).

5. An injection molding method of a two-color injection-molded optical lens, characterized by, The mold for two-color injection molding optical lens of claim 4 further comprises the following steps: Step S10: install the mold to the two-color injection molding machine, and complete the first injection of the first cavity; Step S20: separate the movable mold (3) from the fixed mold (2), and rotate the rotating table of the two-color injection molding machine by 180 degrees; Step S30: the laser displacement sensor (401) acquires the offset amount of the laser signal reflected by the mirror (402), starts the servo motor (103) to drive the rotating seat (102) to rotate, until the laser displacement sensor (401) acquires no offset amount of the reflected laser signal; Step S40: the movable mold (3) and the fixed mold (2) are closed, and the second injection of the first cavity and the first injection of the second cavity are completed.

6. The method of claim 5, wherein The first injection of the first cavity completed by the step S10 is the structure part of the optical lens, and the second injection of the first cavity completed by the step S40 is the optical part of the optical lens.

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