TWI684745B - Calibration system for optical lens mold - Google Patents

Abstract

An optical lens mold correction system. The mold includes a male mold body and a female mold body. The calibration system includes a temperature detection module, a mold temperature control module, and a fuzzy controller. The fuzzy controller can obtain the real-time temperature of the male mold body and the female mold body from the temperature detection module, and calculate the real-time temperature difference, and then obtain the target settings of the male mold body and the female mold body through fuzzy control operations Temperature, and finally adjust the cooling liquid in the male mold body and the female mold body to the target set temperature through the mold temperature control module, so that the instantaneous temperature difference between the male mold body and the female mold body converges within the target temperature difference range, Therefore, the degree of thermal expansion is controlled separately so that the die eccentricity value converges within the target error, so that the problem of excessive die eccentricity can be fundamentally improved.

Description

Calibration system for optical lens mold

The invention relates to a correction system, in particular to a correction system for injection molding optical lens molds.

Injection molding through a mold to form optical lenses is a very common technique, but in the process from preheating to injection molding, the mold will undergo thermal deformation (usually thermal expansion) due to the rise and fall of its temperature, plus mutual The temperature of the combined male mold body and female mold body may not be the same due to various factors, resulting in different deformation amounts of the male mold body and the female mold body, which ultimately makes the mold core of the male mold body and the mold of the female mold body There is an eccentricity value between Yanren, which will cause the problem of insufficient precision due to the excessive eccentricity of the manufactured optical lens.

In order to maintain the yield and accuracy of products, the general injection molding process mostly improves the parameters of the injection machine through various control methods or optimization methods, so that the material injected by the injection machine can indeed conform to the shape of the mold cavity, so as to achieve Reduce or avoid uneven surfaces, internal bubbles, and uneven edge thickness, but this does not solve the situation where the eccentricity between the male and female molds is too large due to thermal expansion, so even The parameters of the injection machine are improved so that it can perfectly conform to the shape of the mold, and the eccentricity of the mold itself is too large, so that the optical lens produced still has the problem of excessive eccentricity.

Therefore, the object of the present invention is to provide a correction system that can correct the eccentricity of the mold due to thermal deformation.

Therefore, the correction system for the mold of the optical lens of the present invention is suitable for a mold, which includes a male mold body and a female mold body that can be opposed to the male mold body. The calibration system includes a temperature detection module for detecting the real-time temperature of the male mold body and the female mold body, and a mold temperature control module for controlling the temperature of the male mold body and the female mold body, And a fuzzy controller electrically connected to the temperature detection module and the mold temperature control module.

The fuzzy controller can obtain the real-time temperature of the male mold body and the female mold body from the temperature detection module, and calculate the real-time temperature difference, and then obtain the temperature adjustment of the male mold body and the female mold body through fuzzy control calculation Finally, through the mold temperature control module, the temperature of the cooling liquid in the male mold body and the female mold body is adjusted according to the temperature adjustment amount, so that the instantaneous temperature difference between the male mold body and the female mold body converges to the target temperature difference range Inside.

The effect of the present invention is that the correction system can adjust the respective temperatures of the male mold body and the female mold body through fuzzy control operations, so as to separately control the degree of thermal expansion thereof so that the mold eccentricity value converges within the target error, so It can fundamentally improve the problem of excessive eccentricity of the mold, thereby reducing the eccentricity of the manufactured optical lens, and improving its yield and accuracy.

1‧‧‧ Calibration system

11‧‧‧Temperature detection module

111‧‧‧ First sensor

112‧‧‧Second sensor

12‧‧‧ Mold temperature control module

121‧‧‧Male mold temperature machine

122‧‧‧Master mold temperature machine

13‧‧‧ fuzzy controller

2‧‧‧Mould

21‧‧‧ Male phantom

210‧‧‧Waterway

22‧‧‧Master phantom

220‧‧‧Waterway

A‧‧‧molecule eccentricity

B‧‧‧Temperature adjustment

T ₁ ‧‧‧ Instant temperature

T ₂ ‧‧‧ Instant temperature

T ₁₁ ‧‧‧ Instant temperature

T ₂₁ ‧‧‧ Instant temperature

△T‧‧‧ Instant temperature difference

Other features and functions of the present invention will be clearly presented in the embodiment with reference to the drawings, in which: FIG. 1 is a schematic diagram of an embodiment of the calibration system of the present invention; FIG. 2 is a schematic diagram of the embodiment Four of the first sensors are arranged on a male mold; Figure 3 is a relationship curve diagram illustrating the relationship between the mold eccentricity value and the instant temperature difference in this embodiment; Figures 4 to 7 are all Relationship graphs illustrating the results obtained in a first experimental example; Figures 8 to 11 are relationship graphs illustrating the results obtained in a second experimental example; and Figures 12 to 17 are relationship graphs illustrating a The results obtained in the third experimental example.

Referring to FIGS. 1 and 2, it is an embodiment of the calibration system 1 of the present invention. This embodiment is applicable to a mold 2 of an optical lens. The mold 2 includes a male mold body 21 and a mold body 21相合的母模体22。 The relative mold body 22. The male mold body 21 and the female mold body 22 are provided with water channels 210 and 220 for cooling liquid and mold cores for alignment. Since the mold cores mentioned above are common knowledge in the field of mold 2 in general, they are not Show in the diagram And not repeat them here. The calibration system 1 includes a temperature detection module 11 disposed on the mold 2, a mold temperature control module 12 connected to the mold 2, and an electrical connection between the temperature detection module 11 and the mold temperature control module Fuzzy controller 13 of group 12. The temperature detection module 11 includes four first sensors 111 embedded in the male mold body 21 and capable of sensing the real-time temperature of the male mold body 21, and four embedded in the female mold body 22 and The second sensor 112 can sense the instant temperature of the master mold body 22. In this embodiment, the first sensors 111 are arranged as shown in FIG. 2, and the second sensors 112 are also arranged in a similar manner, but of course the actual state of the mold 2 can also be used Such configuration changes are not limited to this. The mold temperature control module 12 includes a male mold temperature controller 121 communicating with the water channel 210 of the male mold body 21 for controlling the temperature of the coolant in the water channel 210, and a water channel 220 communicating with the female mold body 22. The master mold temperature controller 122 for controlling the temperature of the cooling liquid in the water channel 220.

Referring to FIG. 1, FIG. 2, and FIG. 3, the calibration method of this embodiment is then described, including a data creation step and a temperature control step. In the step of establishing the data, first perform multiple thermal analysis (simulation or experiment) on the mold 2 under different conditions to obtain a plurality of mold eccentricity values A between the male mold body 21 and the female mold body 22, In addition to obtaining a die eccentricity value A, each thermal analysis will also measure (or simulate) four real-time temperatures T ₁₁ by the first sensors 111 and the second sensors 112 measured (or simulated) four real-time temperatures T ₂₁ , the average of the two sets of real-time temperatures T ₁₁ and T ₂₁ can be obtained to obtain the real-time temperature T _{1 of} the male mold body 21 and the mother mold body The instantaneous temperature T _{2 of} 22 is obtained by subtracting the two instantaneous temperatures T ₁ and T ₂ to obtain the instantaneous temperature difference ΔT between the male mold body 21 and the female mold body 22, so each mold kernel eccentricity value A corresponds to one The instantaneous temperature difference △T can be obtained by reorganizing the die eccentricity value A (unit: μm) and the instantaneous temperature difference △T (unit: ℃) obtained in each thermal analysis to obtain the relationship diagram shown in FIG. 3. In this embodiment , The target error range of the mold core eccentricity value A is ±1, and the corresponding target temperature difference range can be seen from FIG. 3 (the average temperature T ₁ after the average of the male mold body 21 minus the average of the female mold body 22 The resulting immediate temperature T ₂ ) is -0.5°C to -1°C, and the aforementioned target temperature difference range is entered into the database of the fuzzy controller 13. In addition, in this embodiment, the limit value of the temperature AT of the overall mold 2 is set to 110°C according to the characteristics of the plastic material placed in the mold 2. The algorithm of the temperature AT of the overall mold 2 is the instantaneous temperature T of the first sensors 111 ₁₁ and the instantaneous temperatures T _{21 of the} second sensors 112 are added up and averaged.

When the temperature of the mold 2 changes due to pre-heating, injection molding or mold opening, the calibration system 1 can be activated to perform the temperature control step. In the temperature control step, the first sensors 111 and the second sensors 112 input the measured real-time temperatures T ₁₁ and T _{21 to} the fuzzy controller 13, and the fuzzy controller 13 calculates the male phantom 21 and The instant temperature difference ΔT of the master mold body 22. Then the fuzzy controller 13 will use the instantaneous temperature difference △T as the fuzzy input variable, and then use the temperature adjustment amount B of the male mold body 21 or the female mold body 22 as the output variable, after establishing the attribution function and knowledge base, proceed first Fuzzy inference method (Min-Min-Max), and then use the maximum center method (COM) to defuzzify, so as to obtain the output control value (temperature adjustment amount B).

Next, when the real-time overall mold 2 temperature AT is greater than the limit value of 110°C, if the instantaneous temperature difference ΔT is greater than the upper limit of the target temperature difference range -0.5°C, the male mold temperature controller 121 is used to decrease the temperature according to the temperature adjustment amount B If the instantaneous temperature difference △T is less than the lower limit value of the target temperature difference range of -1°C, the cooling temperature of the male mold body 21 is reduced by the master mold temperature machine 122 according to the temperature adjustment amount B液温度。 Liquid temperature. Conversely, when the real-time overall mold 2 temperature AT is less than the limit value of 110°C, if the instantaneous temperature difference ΔT is greater than the upper limit of the target temperature difference range of -0.5°C, the master mold temperature machine 122 is used to raise the master according to the temperature adjustment If the instantaneous temperature difference ΔT is less than the lower limit of the target temperature difference range of -1°C, the temperature of the cooling body of the mold body 22 is increased by the temperature adjustment amount B of the male mold body 121 through the male mold temperature machine 121 The temperature of the male mold body 21 and the female mold body 22 itself can be adjusted by lowering or increasing the coolant temperature, so that the instantaneous temperature difference ΔT between the male mold body 21 and the female mold body 22 converges to the target temperature difference range In addition, the eccentricity value A of the mold core between the male mold body 21 and the female mold body 22 is converged within the target error ±1.

The fuzzy controller 13 can directly perform thermal compensation on the male mold body 21 and the female mold body 22 through the cooling liquid to separately control the thermal expansion amounts of the male mold body 21 and the female mold body 22, and then control the The eccentricity of the mold core between the male mold body 21 and the female mold body 22 converges within the target error, which can greatly improve the accuracy and quality of the manufactured optical lens.

The following further explains the calibration system 1 and the calibration method through experiments The effectiveness of the method is based on the thermal analysis and simulation of the ANSYS software, and the target error range of the eccentricity value A of the model is ±1, and the target temperature difference range is -0.5℃~ At -1°C, the limit value of the temperature AT of the entire mold 2 is 110°C, and the temperature of the cooling liquid of the male mold body 21 and the female mold body 22 is both 110°C.

Experimental example one

Referring to FIGS. 2 and 4 to 7, in this experimental example, the temperature control step is performed after the mold 2 is preheated for 1 hour, and the temperature of the first sensors 111 and the second sensors 112 are captured. The cycle is 30 seconds/time, and the ambient temperature is 25°C. The final results are shown in FIGS. 4 to 7. FIG. 4 is the temperature of the public mold after the fuzzy controller 13 calculates the temperature adjustment amount B. 121 and the female mold temperature controller 122 control the male mold body 21 and the female mold body 22 to obtain a trend diagram of the coolant temperature. FIG. 5 is the first sensors 111 and the first The trend graphs of the instantaneous temperatures T ₁ and T ₂ measured by the two sensors 112. FIG. 6 is the trend graph of the instantaneous temperature difference ΔT between the male mold body 21 and the female mold body 22, due to the preheating period. The mold structure of the male mold body 21 and the female mold body 22 is different, so that the instantaneous temperatures T ₁ and T ₂ between the male mold body 21 and the female mold body 22 are slightly different, thereby forming an instant temperature difference ΔT However, under the control of the correction system 1, after the sixth correction, the instantaneous temperature difference ΔT gradually converges to the target temperature difference range, and it can also be clearly seen from the trend graph of the mold eccentricity value A in FIG. When the calibration is performed, the mold eccentricity value A of the mold 2 gradually converges to the target error range, so the calibration system 1 and the correction method can indeed play a role in reducing the mold core eccentricity value A for the preheated mold 2 .

Experiment 2

Referring to FIG. 2 and FIGS. 8 to 11, in this experimental example, injection molding is performed after the mold 2 is preheated for 1 hour, and then the temperature control step is performed. The preheating parameters of the mold 2 are the same as in Experimental Example 1. The parameters of the mold 2 during injection molding are: the temperature of the vertical sprue is set at 271°C, the temperature of the runner is set at 273°C, the temperature of the product is set at 275°C, the injection time is 0.2 seconds, and the mold opening and closing time (air heat transfer Time) 5 seconds, the time point of temperature acquisition is 25 seconds after the start of the cycle. FIG. 8 is also a trend diagram of the coolant temperature of the male mold body 21 and the female mold body 22 during the experiment, and FIG. 9 is measured by the first sensors 111 and the second sensors 112 The trend graphs of the real-time temperatures T ₁ and T _{2 are obtained} . FIG. 10 is the trend graph of the instantaneous temperature difference ΔT between the male mold body 21 and the female mold body 22, which can be clearly seen from FIG. The temperature difference △T is large, but through the thermal compensation of the correction system 1, the instantaneous temperature difference ΔT gradually converges to the target temperature difference range, and the trend graph of the mold eccentricity value A of FIG. 11 can also be clearly seen. Progress, the mold eccentricity value A of the mold 2 gradually converges to the target error range, so the calibration system 1 and the correction method can indeed reduce the mold core eccentricity value A for the mold 2 after preheating and injection molding Corrective effect.

Experiment 3

Referring to FIGS. 2 and 12 to 17, the experimental example is roughly the same as the experimental example 2, but after the injection molding is stable, the mold 2 is opened and the mold surface is dissipated for 5 minutes as the interference value. The aforementioned procedure was conducted on an experimental group and a control group, which were provided with the calibration system 1 of the present invention. The experimental group and the control group both used the optimal coolant temperature obtained in Experimental Example 2 (Figure 8 The 17th calculation value in) is used as the initial value, that is, the cooling liquid temperature of the male mold body 21 is 102.8°C, and the cooling liquid temperature of the female mold body 22 is 107.4°C. The difference is that the control group is not set The correction system 1. The experimental results are shown in Figs. 12 to 17, and Fig. 12 shows that the coolant temperature of the control group is maintained at 102.8°C and 107.4°C, respectively, and Fig. 13 shows the male mold body 21 and the female mold body 22 of the control group. Real-time temperature T ₁ and T ₂ trend graphs. FIG. 14 is the cooling fluid temperature trend graph of the male mold body 21 and the female mold body 22 of the experimental group during the experiment. When the instantaneous temperature difference △T converges to the target error range When the temperature is within, the coolant temperature will be adjusted back to the initial value (that is, the 17th calculated value in FIG. 8). If the instantaneous temperature difference ΔT exceeds the target error range, the correction system 1 will be activated to adjust, as shown in FIG. 15 The trend graphs of the instantaneous temperatures T ₁ and T ₂ of the male mold body 21 and the female mold body 22 of the experimental group. Fig. 16 is a graph comparing the trend of the instant temperature difference ΔT between the experimental group and the control group. It can be seen from Fig. 16 that although both the experimental group and the control group finally converged within the target error range, the experimental group was After calculation and control, the instantaneous temperature difference ΔT converges to the target error range, and the control group does not converge the instantaneous temperature difference ΔT to the target error range until the 9th molding. Figure 17 shows the experimental group and the The trend graph of the mold eccentricity value A of the control group can be calculated from Figure 17, the average eccentricity error value of the experimental group is 0.18 μm, and the average eccentricity error value of the control group is 0.3 μm. 1 and the correction method not only returns the speed of the best real-time temperature difference faster, but also the overall eccentricity error performance is better than the control group without this correction system 1.

In summary, the calibration system 1 of the present invention can thermally compensate the mold 2 through the calibration method, so that the thermal expansion of the male mold body 21 and the female mold body 22 can be controlled by adjusting the coolant temperature, and then the mold can be controlled The mold eccentricity value of 2 effectively reduces the error of the manufactured optical lens and improves its accuracy, so it can indeed achieve the purpose of cost invention.

However, the above are only examples of the present invention, and should not be used to limit the scope of the present invention. Any simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the patent specification are still classified as This invention covers the patent.

1‧‧‧ Calibration system

11‧‧‧Temperature detection module

111‧‧‧ First sensor

112‧‧‧Second sensor

12‧‧‧ Mold temperature control module

121‧‧‧Male mold temperature machine

122‧‧‧Master mold temperature machine

13‧‧‧ fuzzy controller

2‧‧‧Mould

21‧‧‧ Male phantom

210‧‧‧Waterway

22‧‧‧Master phantom

220‧‧‧Waterway

Claims (3)

A correction system for a mold of an optical lens is suitable for a mold. The mold includes a male mold body and a female mold body corresponding to the male mold body. The correction system includes: a temperature detection module. For detecting the real-time temperature of the male mold body and the female mold body; a mold temperature control module for controlling the temperature of the male mold body and the female mold body; and a fuzzy controller electrically connected to the temperature detection Module and the mold temperature control module, the fuzzy controller can obtain the real-time temperature of the male mold body and the female mold body from the temperature detection module, and calculate the real-time temperature difference, and then obtain the public temperature through the fuzzy control operation The temperature adjustment amount of the mold body and the female mold body, and finally adjusting the temperature of the cooling liquid in the male mold body and the female mold body through the mold temperature control module according to the temperature adjustment amount, so that the male mold body and the female mold The instant temperature difference between the bodies converges within the target temperature difference range. The correction system for a mold of an optical lens according to claim 1, wherein the temperature detection module includes a plurality of first sensors provided on the male mold body, and a plurality of second sensors provided on the female mold body Sensor. The correction system for a mold of an optical lens according to claim 1, wherein the mold temperature control module includes a male mold temperature machine connected to the male mold body and used to control the temperature of the cooling liquid in the male mold body, and a continuous The master mold temperature machine that communicates with the master mold body and is used to control the temperature of the cooling liquid in the master mold body.

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