Injection control method and system of injection molding machine, storage medium and injection molding machine

Abstract

The application relates to an injection molding control method and system of an injection molding machine, a storage medium and the injection molding machine, relates to the technical field of injection molding, and the method comprises the following steps: according to related information of a plastic product, an injection molding strategy corresponding to the related information is acquired, the related information comprises material, structure and size of the plastic product; in the process that the injection molding machine works according to the injection molding strategy, an actual injection molding pressure of the injection molding machine is acquired; according to the actual injection molding pressure and an injection molding stage corresponding to the actual injection molding pressure, the injection molding strategy is updated and executed, and the injection molding stage comprises a filling stage, a pressure maintaining stage and a cooling stage. The application has the effects of optimizing the injection molding strategy of the injection molding machine and improving the quality of the plastic product.

Description

Technical Field

[0001] This application relates to the field of injection molding technology, and in particular to an injection molding machine injection control method, system, storage medium, and injection molding machine. Background Technology

[0002] An injection molding machine is a device that heats and melts plastic granules, injects them into a mold, and then cools and solidifies them to form the desired shape. It is used to produce various plastic products, such as parts, packaging containers, and toys.

[0003] In injection molding, the process involves first adding plastic granules to the barrel and then melting them under the action of a heater to form molten plastic. This molten plastic is then injected into the mold. After injection, the injection molding machine cools the molten plastic in the mold, and once it has solidified, the mold is opened to remove the plastic product.

[0004] Regarding the aforementioned technologies, the inventors believe that during the injection molding process, parameters such as injection pressure and injection temperature can affect the quality of finished plastic products, and these parameters need to be adjusted according to the actual working conditions of the injection molding machine. Summary of the Invention

[0005] In order to optimize the injection strategy of injection molding machines and improve the quality of plastic products, this application provides an injection control method, system, storage medium, and injection molding machine for injection molding machines.

[0006] Firstly, this application provides an injection control method for an injection molding machine, employing the following technical solution:

[0007] An injection control method for an injection molding machine, comprising:

[0008] Based on relevant information about the plastic product, obtain the corresponding injection molding strategy. The relevant information includes the material, structure, and dimensions of the plastic product.

[0009] During the process of the injection molding machine working according to the injection molding strategy, the actual injection pressure of the injection molding machine is obtained;

[0010] The injection strategy is updated and executed based on the actual injection pressure and the corresponding injection stage, which includes the filling stage, holding pressure stage, and cooling stage.

[0011] By adopting the above technical solution, the injection strategy is updated and executed based on the actual injection pressure of the injection molding machine and the corresponding injection stage. This method allows the injection strategy to be adjusted according to the requirements of different injection stages, ensuring that the injection strategy always meets the needs and effectively improving the quality of plastic products.

[0012] Optionally, obtain the timestamp information corresponding to the actual injection pressure;

[0013] Based on the timestamp information, find the expected injection pressure corresponding to the timestamp information in the injection strategy;

[0014] Determine whether the actual injection pressure matches the expected injection pressure;

[0015] If so, then keep the injection molding strategy unchanged and execute the injection molding strategy;

[0016] If not, determine the injection stage based on the timestamp information; update the injection strategy based on the actual injection pressure and injection stage, and execute the updated injection strategy.

[0017] By adopting the above technical solution, the injection strategy is determined by judging whether the actual injection pressure is consistent with the expected injection pressure, so that the injection strategy can always meet the needs of different injection stages.

[0018] Optionally, if the injection stage is the filling stage and the actual injection pressure is greater than the expected injection pressure, the injection pressure in the filling stage of the injection strategy is updated according to the difference between the actual injection pressure and the expected injection pressure.

[0019] If the actual injection pressure is less than the expected injection pressure, determine whether the actual injection pressure has reached the upper limit of the injection molding machine's pressure supply. If not, update the injection pressure of the filling stage in the injection strategy based on the difference between the expected and actual injection pressure. If yes, determine whether the plastic product material is a temperature-sensitive material.

[0020] If so, obtain the material flow curve of the plastic product. The flow curve is used to represent the mapping relationship between the flow of plastic and temperature. Based on the actual injection pressure and the expected injection duration of the injection stage in the injection strategy, obtain the target flow. Find the target injection temperature corresponding to the target flow in the flow curve. Update the injection temperature of the filling stage in the injection strategy according to the target injection temperature.

[0021] If not, the duration of the filling stage in the injection molding strategy is extended according to the first preset ratio.

[0022] By adopting the above technical solution, during the filling stage, the injection molding machine can determine which parameters in the injection strategy should be updated based on data such as the material of the plastic product, the expected injection pressure and the actual injection pressure, so as to optimize the injection strategy and improve the quality of the plastic product.

[0023] Optionally, based on the injection molding strategy, the first cooling rate of the injection molding machine during the holding pressure stage can be obtained;

[0024] Determine the holding temperature of the plastic material based on the material of the plastic product;

[0025] Determine whether the temperature difference between the target injection temperature and the holding pressure temperature is greater than a preset difference;

[0026] If not, the duration of the holding pressure phase in the injection molding strategy remains unchanged;

[0027] If so, calculate the ratio of the temperature difference to the first cooling rate to obtain the holding time; extend the holding time of the holding stage in the injection molding strategy according to the holding time; reduce the injection pressure of the holding stage in the injection molding strategy according to the second preset ratio.

[0028] By adopting the above technical solution, the duration and injection pressure of the holding pressure stage are adjusted so that the injection processing in the holding pressure stage can compensate for the impact of the optimization of the injection strategy in the filling stage, and the injection strategy meets the requirements of the holding pressure stage.

[0029] Optionally, based on the injection molding strategy, a second cooling rate of the injection molding machine during the cooling phase can be obtained;

[0030] Based on relevant information, obtain the maximum cooling rate of the plastic product during the cooling stage, as well as the critical cooling temperature of the plastic product. The maximum cooling rate is greater than the second cooling rate.

[0031] Based on the second cooling rate, the maximum cooling rate, and the critical cooling temperature, the cooling stage in the injection molding strategy is updated so that the plastic product is cooled at the second cooling rate at the beginning of the cooling stage, and cooled at the maximum cooling rate when the temperature of the plastic product reaches the critical cooling temperature.

[0032] By adopting the above technical solution, the cooling rate in the cooling stage is adjusted so that the injection molding process in the cooling stage can compensate for the impact of the optimization of the injection molding strategy in the filling stage, and the injection molding strategy can meet the requirements of the cooling stage.

[0033] Optionally, if the injection stage is the holding pressure stage, calculate the injection pressure difference between the actual injection pressure and the desired injection pressure.

[0034] Count the number of injection pressure differences that exceed the preset pressure difference value;

[0035] Determine if the number of differences is greater than the preset number;

[0036] If so, then determine the third preset ratio based on the difference; increase the injection pressure in the holding stage of the injection molding strategy according to the third preset ratio;

[0037] If not, the injection molding strategy will remain unchanged.

[0038] By adopting the above technical solution, when the injection molding stage is the holding pressure stage, the injection pressure in the holding pressure stage will be increased when the difference exceeds the preset amount, so as to ensure that various parameters in the holding pressure stage meet the requirements and improve the quality of plastic products.

[0039] Optionally, obtain the temperature distribution of the plastic product;

[0040] Calculate the average temperature of the plastic product based on the temperature distribution;

[0041] The low-temperature region is obtained by identifying areas on a plastic product where the temperature is lower than the average temperature.

[0042] For low-temperature regions, reduce the cooling rate during the holding pressure stage in the injection molding strategy.

[0043] By adopting the above technical solution, the cooling rate of the low-temperature region is changed during the pressure holding stage, so that the low-temperature region can cool at a slower rate. This can make the overall temperature of the plastic product more balanced, solve the problem of uneven pressure distribution caused by uneven temperature distribution, and improve the quality of the plastic product.

[0044] Secondly, this application provides an injection control system for an injection molding machine, which adopts the following technical solution:

[0045] An injection control system for an injection molding machine, comprising:

[0046] The acquisition module is used to acquire relevant information, actual injection pressure, timestamp information, pressure power supply limit, flow curve, first preset ratio, second preset ratio, first cooling rate, second cooling rate, preset quantity, and temperature distribution.

[0047] A memory for storing the program of the injection control method for any of the above-mentioned injection molding machines;

[0048] A processor, a program in memory that can be loaded and executed by the processor and implement any of the above-mentioned injection molding machine injection control methods.

[0049] By adopting the above technical solution, the injection strategy is updated and executed based on the actual injection pressure of the injection molding machine and the corresponding injection stage. This method allows the injection strategy to be adjusted according to the requirements of different injection stages, ensuring that the injection strategy always meets the needs and effectively improving the quality of plastic products.

[0050] Thirdly, this application provides an injection molding machine, which adopts the following technical solution:

[0051] An injection molding machine includes a memory and a processor, wherein the memory stores a computer program that can be loaded by the processor and executed according to any of the methods described above.

[0052] By adopting the above technical solution, the injection strategy is updated and executed based on the actual injection pressure of the injection molding machine and the corresponding injection stage. This method allows the injection strategy to be adjusted according to the requirements of different injection stages, ensuring that the injection strategy always meets the needs and effectively improving the quality of plastic products.

[0053] Fourthly, this application provides a computer storage medium capable of storing corresponding programs, which facilitates the implementation of injection molding strategies for optimizing injection molding machines and improving the quality of plastic products. The technical solution adopted is as follows:

[0054] A computer-readable storage medium storing a computer program that can be loaded by a processor and executed for any of the above-described injection molding machine injection control methods.

[0055] By adopting the above technical solution, the injection strategy is updated and executed based on the actual injection pressure of the injection molding machine and the corresponding injection stage. This method allows the injection strategy to be adjusted according to the requirements of different injection stages, ensuring that the injection strategy always meets the needs and effectively improving the quality of plastic products.

[0056] In summary, this application includes at least one of the following beneficial technical effects:

[0057] 1. Update and execute the injection strategy based on the actual injection pressure of the injection molding machine and the corresponding injection stage. This method allows the injection strategy to be adjusted according to the requirements of different injection stages, ensuring that the injection strategy always meets the needs and effectively improving the quality of plastic products.

[0058] 2. During the filling stage, the injection molding machine determines which parameters in the injection strategy should be updated based on data such as the material of the plastic product, the expected injection pressure, and the actual injection pressure. This optimizes the injection strategy and improves the quality of the plastic product. 3. When the injection stage is the holding pressure stage, the injection pressure during the holding pressure stage will be increased if the difference exceeds a preset amount. This ensures that various parameters during the holding pressure stage meet the requirements and improves the quality of the plastic product. Attached Figure Description

[0059] Figure 1 This is a schematic flowchart of an injection control method for an injection molding machine disclosed in an embodiment of this application.

[0060] Figure 2 This is a schematic flowchart of an injection control method for an injection molding machine disclosed in an embodiment of this application.

[0061] Figure 3 This is a schematic flowchart of an injection control method for an injection molding machine disclosed in an embodiment of this application.

[0062] Figure 4 This is a schematic flowchart of an injection control method for an injection molding machine disclosed in an embodiment of this application.

[0063] Figure 5 This is a schematic flowchart of an injection control method for an injection molding machine disclosed in an embodiment of this application.

[0064] Figure 6 This is a schematic flowchart of an injection control method for an injection molding machine disclosed in an embodiment of this application.

[0065] Figure 7 This is a schematic flowchart of an injection control method for an injection molding machine disclosed in an embodiment of this application.

[0066] Figure 8 This is a schematic diagram of an injection control system for an injection molding machine disclosed in an embodiment of this application. Detailed Implementation

[0067] To make the purpose, technical solution, and advantages of this application clearer, the following description is provided in conjunction with the appendix. Figure 1-8 The present application will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the application.

[0068] This application discloses an injection control method for an injection molding machine. (Refer to...) Figure 1 The method includes:

[0069] Step S11: Based on the relevant information of the plastic product, obtain the injection molding strategy corresponding to the relevant information, including the material, structure and size of the plastic product.

[0070] Injection molding strategy refers to the control method of injection molding machines when manufacturing plastic products. These parameters include injection pressure, injection temperature, injection time, and cooling rate. Injection pressure refers to the pressure of the molten plastic extruded by the injection molding machine; injection temperature refers to the temperature of the molten plastic extruded from the nozzle; and injection time refers to the relative time of a single injection cycle. For example, with an injection time of 5 seconds, the injection molding machine needs to provide an injection pressure of 50 MPa and control the injection temperature of the molten plastic at 180°C.

[0071] For example, the injection molding machine's memory stores the correspondence between relevant information and preset injection strategies; the injection strategy corresponding to the relevant information is found based on the correspondence.

[0072] For example, the injection molding machine searches for the injection strategy in the historical operation record based on relevant information.

[0073] Step S12: During the process of the injection molding machine working according to the injection molding strategy, obtain the actual injection pressure of the injection molding machine.

[0074] Actual injection pressure refers to the pressure of molten plastic extruded from the nozzle of the injection molding machine during actual operation. In some embodiments, a pressure sensor is installed on the nozzle of the injection molding machine to detect the actual injection pressure.

[0075] Step S13: Update and execute the injection strategy based on the actual injection pressure and the corresponding injection stage. The injection stages include the filling stage, the holding pressure stage, and the cooling stage.

[0076] The filling stage refers to the process of injecting plastic into a mold, where higher injection pressure is required to ensure that the molten plastic completely fills all the details of the mold.

[0077] The holding pressure stage refers to maintaining the injection pressure at a high level after filling is completed, in order to compensate for the shrinkage of the plastic during cooling and ensure product dimensional stability.

[0078] The cooling stage refers to the gradual reduction of injection pressure after the plastic has cooled and solidified, until the injection process is completed.

[0079] In this embodiment, the injection molding strategy is divided according to the injection molding stage. For example, in the filling stage, the injection molding machine fills the mold with molten plastic at an injection pressure of 50 MPa, and the temperature of the molten plastic is 170°C; in the holding stage, the injection molding machine maintains the injection pressure at 40 MPa; in the cooling stage, the injection molding machine reduces the injection pressure over time, and releases the plastic product after it has solidified.

[0080] In summary, the injection strategy is updated and executed based on the actual injection pressure of the injection molding machine and the corresponding injection stage. This method allows the injection strategy to be adjusted according to the requirements of different injection stages, ensuring that the injection strategy always meets the needs and effectively improving the quality of plastic products.

[0081] In the following embodiments, for Figure 1 In step S13 of the illustrated embodiment, this embodiment determines whether the injection strategy needs to be changed by judging whether the actual injection pressure is consistent with the expected injection pressure. This application discloses an injection control method for an injection molding machine. (Refer to...) Figure 2 The method includes:

[0082] Step S201: Obtain the timestamp information corresponding to the actual injection pressure.

[0083] The timestamp information indicates the time when the actual injection pressure was read. Furthermore, the timestamp information is divided according to a single injection process. For example, if each injection takes 35 seconds, the timestamp information will record which second within those 35 seconds the actual injection pressure was read.

[0084] Step S202: Based on the timestamp information, find the expected injection pressure corresponding to the timestamp information in the injection strategy.

[0085] Expected injection pressure refers to the injection pressure recorded in the injection strategy.

[0086] Optionally, the injection strategy records the injection pressure and injection time, so the expected injection pressure corresponding to the timestamp information can be determined by the injection time.

[0087] Step S203: Determine whether the actual injection pressure is consistent with the expected injection pressure.

[0088] If the actual injection pressure matches the expected injection pressure, then proceed to step S204.

[0089] If the actual injection pressure is inconsistent with the expected injection pressure, then proceed to step S205.

[0090] Step S204: If yes, then keep the injection molding strategy unchanged and execute the injection molding strategy.

[0091] If the actual injection pressure matches the expected injection pressure, it indicates that the injection molding machine is executing the preset injection strategy, the machine is operating normally, and there is no need to update the injection strategy.

[0092] Step S205: If not, determine the injection molding stage based on the timestamp information.

[0093] If the actual injection pressure is inconsistent with the expected injection pressure, it indicates that the injection molding machine is not executing the preset injection strategy and the machine's working status is abnormal. The injection strategy of the injection molding machine needs to be updated to ensure the quality of the plastic products.

[0094] Furthermore, since the injection molding strategy is divided according to the injection molding stage, the injection molding stage corresponding to the timestamp information can be determined through the injection molding strategy.

[0095] Step S206: Update the injection strategy based on the actual injection pressure and injection stage, and execute the updated injection strategy.

[0096] In this application, different methods need to be adopted to update the injection molding strategy according to different stages of injection molding in order to ensure the quality of plastic products and to shorten the processing time of each plastic product as much as possible. Specific implementation methods can be found in the following embodiments, which will not be elaborated here.

[0097] In other aspects of this embodiment, for different injection molding stages, a current long vector is generated based on various parameters of the current injection molding stage. This current long vector includes injection molding parameters, environmental parameters of the injection molding machine's environment, and the current injection molding strategy of the injection molding machine. Injection molding parameters include, but are not limited to, at least one of injection pressure, injection temperature, and plastic flow rate. Environmental parameters include, but are not limited to, at least one of ambient temperature, ambient humidity, and time. Based on the historical records of the injection molding machine under different scenarios, several historical long vectors are statistically generated, each corresponding to a scenario. Based on the scenario corresponding to the current long vector, its corresponding historical long vector is determined, and the similarity between the current long vector and the historical long vector is calculated. Using the similarity as feedback, the working state of the injection molding machine is adjusted to make the current long vector closely approximate the aforementioned historical long vector.

[0098] In summary, by determining whether the actual injection pressure matches the expected injection pressure, the injection strategy can be determined so that the injection strategy can always meet the needs of different injection stages.

[0099] In the following embodiments, where the injection stage is a filling stage, more consideration needs to be given to how to fully fill the mold with molten plastic, ensuring it completely occupies all the details of the mold. Therefore, this application discloses an injection control method for an injection molding machine. (Refer to...) Figure 3 The method includes:

[0100] Step S301: If the actual injection pressure is greater than the expected injection pressure when the injection stage is the filling stage, then update the injection pressure of the filling stage in the injection strategy according to the difference between the actual injection pressure and the expected injection pressure.

[0101] For example, when the actual injection pressure is greater than the expected injection pressure, the injection pressure in the filling stage of the injection strategy can be reduced directly based on the difference between the actual and expected injection pressure. Furthermore, after the injection molding machine executes the updated injection strategy, the actual injection pressure can be detected, and it can be determined again whether the actual injection pressure is the same as the expected injection pressure. If they are the same, the process of this embodiment ends; if they are different, injection is paused, and an error signal is sent to the user terminal. This error signal indicates a problem with the injection pressure control system of the injection molding machine.

[0102] Step S302: If the actual injection pressure is less than the expected injection pressure, determine whether the actual injection pressure has reached the upper limit of the injection molding machine's pressure supply.

[0103] If the actual injection pressure reaches the upper limit of the injection molding machine's pressure supply, then proceed to steps S304 to S309.

[0104] If the actual injection pressure reaches the upper limit of the injection molding machine's pressure supply, then proceed to step S303.

[0105] The pressure function limit refers to the maximum injection pressure that the injection molding machine can provide during actual operation.

[0106] When the actual injection pressure exceeds the expected injection pressure, it is also necessary to consider whether the actual injection pressure has reached the upper limit of the pressure function that the injection molding machine can provide. In actual production scenarios, due to various reasons such as aging and wear of the injection molding machine and damage to parts, the output power of the injection molding machine will be reduced, causing the upper limit of the pressure supply capacity of the injection molding machine to decrease. Therefore, it is necessary to first determine whether the actual injection pressure has reached the upper limit of the pressure supply capacity of the injection molding machine to determine whether the actual injection pressure of the injection molding machine can be further increased.

[0107] Step S303: If not, update the injection pressure of the filling stage in the injection strategy based on the difference between the expected injection pressure and the actual injection pressure.

[0108] For example, the difference between the desired injection pressure and the actual injection pressure is increased, and the injection pressure in the filling stage of the injection molding strategy is updated. This step requires that the desired injection pressure be less than the upper limit of the injection molding machine's pressure supply.

[0109] In another scenario, the desired injection pressure is greater than the upper limit of the injection molding machine's pressure supply. However, the injection molding machine still cannot provide sufficient injection pressure. In this case, step S304 will be executed.

[0110] Step S304: If yes, determine whether the material of the plastic product is a temperature-sensitive material.

[0111] If the plastic product is made of a temperature-sensitive material, proceed to steps S305 to S308.

[0112] If the material of the plastic product is not a temperature-sensitive material, proceed to step S309.

[0113] Temperature-sensitive materials refer to plastic materials whose fluidity changes more than a preset value under a unit temperature change. Examples of temperature-sensitive materials include polyethylene (PE), polypropylene (PP), polycarbonate (PC), polyamide (PA), polyoxymethylene (POM), and polyphenylene sulfide (PPS).

[0114] Step S305: If yes, then obtain the material flow curve of the plastic product. The flow curve is used to represent the mapping relationship between the flowability of the plastic and temperature.

[0115] Optionally, flowability can be represented by melt flow rate (MFR) or melt flow index (MFI). Taking MFR as an example, the flowability curve is a curve with temperature on the x-axis and MFR value on the y-axis.

[0116] Alternatively, fluidity can also be expressed using viscosity. In this case, the fluidity curve is a curve with temperature on the x-axis and viscosity value on the y-axis.

[0117] Step S306: Obtain the target flowability based on the actual injection pressure and the expected injection duration of the injection stage in the injection strategy.

[0118] Expected injection time refers to the time required to fill the mold in an injection strategy. Alternatively, expected injection time can also refer to the total time of the filling phase.

[0119] For example, taking MFI as an example of flowability, the remaining injection time is obtained based on the difference between the expected injection time and the actual injection time; the injection speed is calculated based on the actual injection pressure; the volume of plastic in the mold is calculated based on the injection speed and the actual injection time; the remaining volume of the mold is obtained by calculating the difference between the total volume of the mold and the volume of plastic; and the target flowability is obtained based on the ratio of the remaining volume to the remaining injection time.

[0120] Step S307: Find the target injection temperature corresponding to the target flowability in the flowability curve.

[0121] Since the plastic product uses temperature-sensitive materials, this embodiment modifies the flowability of the molten plastic by changing the injection temperature to compensate for insufficient injection pressure provided by the injection molding machine. This allows the mold to be filled with molten plastic without extending the filling stage.

[0122] Step S308: Update the injection temperature of the filling stage in the injection strategy according to the target injection temperature.

[0123] For example, the injection temperature in the filling stage of the injection molding strategy is updated to the target injection temperature. For instance, the nozzle of the injection molding machine is equipped with a heating device, and the injection temperature of the molten plastic extruded from the nozzle is changed by changing the temperature of the heating device.

[0124] Step S309: If not, extend the duration of the filling stage in the injection molding strategy according to the first preset ratio.

[0125] If the plastic product is not made of a temperature-sensitive material, the injection molding machine can compensate for the insufficient injection pressure by extending the filling stage, so that the molten plastic can fill the mold.

[0126] The first preset ratio is a constant. For example, if the first preset ratio is 20%, then if the filling stage in the original injection molding strategy is 20 seconds, then after extending it according to the first preset ratio, the filling stage duration becomes 24 seconds.

[0127] In other aspects of this embodiment, a preset conversion formula is invoked to process the mold temperature data to obtain the ideal injection pressure; the difference between the actual injection pressure and the ideal injection pressure is compared to see if it is less than a preset difference threshold; if not, the injection pressure of the injection molding machine in the next filling stage is adjusted according to the difference between the actual injection pressure and the ideal injection pressure.

[0128] The preset conversion formula is:

[0129]

[0130] F represents the ideal injection pressure, α is the preset conversion factor, and T... k Let L be the mold temperature at point k on the injection mold. k Let S be the distance from the k-th point on the injection mold to the injection port, and let S be the surface area of ​​the injection mold.

[0131] In summary, during the filling stage, the injection molding machine determines which parameters in the injection strategy should be updated based on data such as the material of the plastic product, the expected injection pressure, and the actual injection pressure. This optimizes the injection strategy and improves the quality of the plastic product.

[0132] In the following embodiments, if in Figure 3 In the illustrated embodiment, increasing the temperature is used to address the insufficient injection pressure provided by the injection molding machine. However, this leads to an excessively high temperature in the molten plastic, causing volume expansion and affecting compensation for plastic shrinkage during the holding pressure stage. To solve the aforementioned problem, this application discloses an injection control method for an injection molding machine. (Refer to...) Figure 4 The method includes:

[0133] Step S401: According to the injection molding strategy, obtain the first cooling rate of the injection molding machine during the holding pressure stage.

[0134] The first cooling rate refers to the temperature drop per second of the plastic during the holding pressure phase in an injection molding strategy.

[0135] Step S402: Determine the holding temperature of the plastic material based on the material of the plastic product.

[0136] Holding pressure temperature refers to the temperature required for the plastic to transition from the holding pressure stage to the cooling stage in an injection molding machine. Furthermore, the holding pressure temperature is related to the curing temperature of the plastic, and it is higher than the curing temperature. For example, if the difference between the holding pressure temperature and the curing temperature is constant, then if the curing temperature is 120°C, the holding pressure temperature could be 130°C. For instance, by scaling up the curing temperature by a preset ratio, the holding pressure temperature can be obtained. If the curing temperature is 120°C, then scaling it up by 10% yields a holding pressure temperature of 132°C.

[0137] Step S403: Determine whether the temperature difference between the target injection temperature and the holding pressure temperature is greater than the preset difference.

[0138] If the temperature difference between the target injection temperature and the holding pressure temperature is greater than the preset difference, then proceed to steps S405 to S407.

[0139] If the temperature difference between the target injection temperature and the holding pressure temperature is not greater than the preset difference, then proceed to step S404.

[0140] The preset difference is a constant; for example, the preset difference is 20°C.

[0141] Step S404: If not, then maintain the duration of the holding pressure stage in the injection molding strategy unchanged.

[0142] If the temperature difference between the target injection temperature and the holding pressure temperature is not greater than the preset difference, it means that the time required to cool down the target injection temperature to the holding pressure temperature is within the tolerable error range, and there is no need to change the duration of the holding pressure stage in the injection strategy.

[0143] Step S405: If so, calculate the ratio of the temperature difference to the first cooling rate to obtain the pressure holding time.

[0144] If the temperature difference between the target injection temperature and the holding pressure temperature is greater than a preset difference, it indicates that the time required to cool from the target injection temperature to the holding pressure temperature has exceeded the error range, thus extending the duration of the holding pressure stage in the injection molding strategy. In this embodiment, the molten plastic is heated to the target injection temperature and then extruded into the mold. If the holding pressure stage duration is not changed, the temperature of the plastic entering the cooling stage will be higher than the holding pressure temperature. Due to the thermal expansion and contraction characteristics of plastic, the plastic will further shrink after cooling to the holding pressure temperature, resulting in the size of the produced plastic product being smaller than the standard size, affecting the quality of the plastic product. Therefore, this embodiment avoids the above situation by increasing the duration of the holding pressure stage.

[0145] Step S406: Extend the duration of the holding pressure stage in the injection molding strategy according to the holding pressure duration.

[0146] For example, the duration of the holding pressure phase in the injection molding strategy can be extended to the aforementioned holding pressure duration.

[0147] Step S407: Reduce the injection pressure during the holding stage of the injection molding strategy according to the second preset ratio.

[0148] Because plastic products are made of temperature-sensitive materials, and plastic has a relatively high temperature, molten plastic has good fluidity and can be injected into the mold with lower injection pressure to fill the details in the mold.

[0149] In actual production scenarios, the injection pressure during the holding stage is usually lower than the injection pressure during the filling stage. Therefore, injection molding machines can usually generate the injection pressure required for the holding stage.

[0150] Furthermore, if the injection pressure in the holding stage of the injection molding strategy is increased by the second preset ratio and the injection pressure is less than the upper limit of the pressure supply of the injection molding machine, then the injection pressure in the holding stage of the injection molding strategy is set as the upper limit of the pressure supply, and the duration of the holding stage in the injection molding strategy is extended again based on the difference between the increased injection pressure and the upper limit of the pressure supply.

[0151] For example, if the difference between the increased injection pressure and the upper limit of the pressure supply is 1 MPa, then the duration of the holding pressure stage in the extended injection strategy is further extended by t = kp, where p is the aforementioned difference in MPa, and k is a constant, for example, k = 1.5.

[0152] The second preset ratio is a constant. For example, if the second preset ratio is 20%, then if the injection pressure in the holding stage of the original injection molding strategy is 40MPa, then after reducing it according to the second preset ratio, the injection pressure in the holding stage becomes 32MPa.

[0153] In summary, by adjusting the duration and injection pressure of the holding pressure stage, the injection process during the holding pressure stage can compensate for the impact of the optimization of the injection strategy during the filling stage, and the injection strategy meets the requirements of the holding pressure stage.

[0154] In the following embodiments, in Figure 4 In the illustrated embodiment, by extending the duration of the holding pressure phase in the injection molding strategy, the duration of the cooling phase can be shortened to ensure that the total duration of the injection molding phase is within the error range. Therefore, this application discloses an injection molding control method for an injection molding machine. (Refer to...) Figure 5 The method includes:

[0155] Step S501: According to the injection molding strategy, obtain the second cooling rate of the injection molding machine during the cooling stage.

[0156] The second cooling rate refers to the temperature drop per second of the plastic during the cooling phase of the injection molding strategy.

[0157] Optionally, the injection strategy records the injection stage and cooling rate, so a second cooling rate of the injection molding machine during the cooling stage can be obtained through the injection strategy.

[0158] Step S502: Based on relevant information, obtain the maximum cooling rate of the plastic product during the cooling stage and the critical cooling temperature of the plastic product. The maximum cooling rate is greater than the second cooling rate.

[0159] The maximum cooling rate refers to the maximum acceptable rate at which a plastic product can be cooled. When the cooling rate exceeds the maximum cooling rate, stress and warping will occur within the plastic product, leading to dimensional inaccuracies or structural damage. For example, the maximum cooling rate is an empirical value.

[0160] The structural strength of a plastic product at a temporary cooling temperature is greater than a predetermined strength. Because the plastic in the mold changes from a molten state to a solid state, the structural strength of the plastic product increases as the temperature decreases. This structural strength includes at least one of the following: tensile strength, compressive strength, flexural strength, shear strength, fatigue strength, stiffness, and toughness.

[0161] Step S503: Update the cooling stage in the injection molding strategy according to the second cooling rate, the maximum cooling rate and the critical cooling temperature, so that the plastic product is cooled at the second cooling rate at the beginning of the cooling stage, and cooled at the maximum cooling rate when the temperature of the plastic product reaches the critical cooling temperature.

[0162] In this step, the cooling process is divided into two stages: the first stage involves cooling the plastic to the critical cooling temperature using a second cooling rate, and the second stage involves cooling the plastic at the maximum cooling rate. In the first stage, cooling the plastic at the second cooling rate ensures that the plastic product will not crack or be damaged, thus guaranteeing its quality. In the second stage, cooling the plastic at the maximum cooling rate shortens the cooling time, and because the plastic itself already possesses a certain structural strength in the second stage, using the maximum cooling rate has minimal impact on the structure and dimensions of the plastic product.

[0163] In some other embodiments, when the temperature of the plastic product has not reached the critical cooling temperature, the temperature distribution of the plastic product is obtained; when the temperature distribution does not meet the preset temperature distribution, an abnormal temperature region in the plastic product is obtained; the abnormal temperature region is heated; when the temperature of the abnormal temperature region reaches the preset temperature, the plastic product in the abnormal temperature region is recycled into the nozzle of the injection molding machine; the injection molding strategy is updated according to the location and temperature distribution of the abnormal temperature region. For example, when the temperature in the abnormal temperature region is too low, the cooling rate of the cooling stage can be reduced and the duration of the holding pressure stage can be extended; when the temperature in the abnormal temperature region is too high, the cooling rate of the cooling stage can be increased and the duration of the holding pressure stage can be extended.

[0164] In some other embodiments, during the cooling phase, the ambient temperature of the injection molding machine is acquired; it is determined whether the ambient temperature is less than a preset temperature threshold; if not, the injection molding strategy remains unchanged; if so, the cooling rate of the cooling phase in the injection molding strategy is reduced based on the difference between the ambient temperature and the preset temperature threshold; the extension time of the cooling phase in the injection molding strategy is calculated based on the updated cooling rate; and the duration of the holding pressure phase in the injection molding strategy is shortened based on the extension time.

[0165] In some other embodiments, during the cooling phase, the ambient temperature of the injection molding machine is acquired; it is determined whether the ambient temperature is less than a preset temperature threshold; if not, the injection molding strategy remains unchanged; if so, the cooling rate of the cooling phase in the injection molding strategy is reduced based on the difference between the ambient temperature and the preset temperature threshold; the extension time of the cooling phase in the injection molding strategy is calculated based on the updated cooling rate; and the duration of the holding pressure phase in the injection molding strategy is shortened based on the extension time.

[0166] In summary, adjusting the cooling rate during the cooling stage allows the injection molding process during the cooling stage to compensate for the impact of optimizing the injection molding strategy during the filling stage, thus ensuring that the injection molding strategy meets the requirements of the cooling stage.

[0167] In the following embodiments, when the injection molding stage is the holding pressure stage, it is necessary to consider that the plastic will shrink during cooling. Therefore, it is necessary to maintain a relatively high injection pressure to ensure the structural and dimensional stability of the plastic product. Thus, how to maintain stable injection pressure during the holding pressure stage is the main issue considered in this embodiment. Therefore, this application discloses an injection molding control method for an injection molding machine. (Refer to...) Figure 6 The method includes:

[0168] Step S601: When the injection stage is the holding pressure stage, calculate the injection pressure difference between the actual injection pressure and the expected injection pressure.

[0169] In this embodiment, the desired injection pressure refers to the injection pressure during the holding phase of the injection strategy.

[0170] Optionally, the mold consists of multiple sub-molds, each equipped with at least one pressure sensor. For example, the mold can produce 10 plastic products at once, with 10 sub-molds, each used to produce one plastic product.

[0171] Optionally, multiple pressure sensors are installed on the mold to obtain the actual injection pressure.

[0172] Step S602: Count the number of injection pressure differences that are greater than the preset pressure difference value.

[0173] The preset pressure difference value is a preset constant, for example, the preset pressure difference value is 1.2 MPa.

[0174] Step S603: Determine whether the number of differences is greater than the preset number.

[0175] If the number of differences is greater than the preset number, then proceed to steps S604 to S605.

[0176] If the number of differences is not greater than the preset number, then proceed to step S606.

[0177] The preset quantity is a preset constant, for example, the preset quantity is 5.

[0178] Step S604: If so, determine the third preset ratio based on the number of differences.

[0179] If the difference is greater than the preset number, it means that the injection molding strategy actually used by the injection molding machine has deviated significantly from the preset injection molding strategy, and therefore the executed injection molding strategy needs to be updated.

[0180] For example, the injection molding machine's memory stores a correspondence between the difference quantity and a third preset ratio. The injection molding machine can directly look up the third preset ratio in the correspondence based on the difference quantity. For instance, when the difference quantity is 6, the third preset ratio is 10%; when the difference quantity is 7, the third preset ratio is 12.

[0181] Step S605: Increase the injection pressure during the holding stage of the injection molding strategy according to the third preset ratio.

[0182] During the holding pressure stage, if there are multiple instances where the actual injection pressure differs from the expected injection pressure, it indicates pressure fluctuations in the injection molding machine during this stage. In such cases, it is necessary to increase the injection pressure to ensure stability. Conversely, reducing the injection pressure may lead to insufficient holding pressure, thereby affecting the quality of the plastic product.

[0183] It should be noted that this step will increase the injection pressure to the maximum holding pressure. The maximum holding pressure refers to the maximum pressure that the mold and plastic material can withstand during the holding pressure stage; this maximum holding pressure is an empirical value.

[0184] Step S606: If not, maintain the injection molding strategy unchanged.

[0185] If the difference is not greater than the preset number, it means that the injection strategy actually used by the injection molding machine has not deviated significantly from the preset injection strategy, so there is no need to update the executed injection strategy.

[0186] In summary, when the injection molding stage is the holding pressure stage, the injection pressure during the holding pressure stage will be increased if the difference exceeds the preset amount. This ensures that various parameters during the holding pressure stage meet the requirements, thereby improving the quality of plastic products.

[0187] In the following embodiments, in Figure 6 In the illustrated embodiment, when fluctuations in injection pressure occur during the holding pressure stage of the injection molding machine, the flow of the plastic can be promoted by changing the temperature distribution of the plastic within the mold, thereby mitigating the impact of pressure fluctuations. Therefore, this application discloses an injection control method for an injection molding machine. (Refer to...) Figure 7 The method includes:

[0188] Step S701: Obtain the temperature distribution of the plastic product.

[0189] Temperature distribution is used to represent the temperature at different locations on a plastic product within a mold.

[0190] Optionally, the mold consists of multiple sub-molds, each equipped with at least one temperature sensor, and can produce multiple plastic products in a single injection molding process. For example, the mold can produce 10 plastic products at once, with 10 sub-molds, each used to produce one plastic product.

[0191] Step S702: Calculate the average temperature of the plastic product based on the temperature distribution.

[0192] For example, the sum of temperatures at each location is calculated based on the temperature distribution; the ratio of the sum of temperatures to the number of temperatures is then calculated to obtain the average temperature.

[0193] Step S703: Obtain the area on the plastic product where the temperature is lower than the average temperature to obtain the low-temperature area.

[0194] The fluidity of plastics is worse in low-temperature regions than in other regions. Therefore, this step requires first determining the location of the low-temperature region, and then treating the low-temperature region separately.

[0195] Step S704: For the low-temperature region, reduce the cooling rate of the holding pressure stage in the injection molding strategy.

[0196] This step reduces the cooling rate in the low-temperature zone, making the plastic temperature more uniform throughout the mold and resolving uneven pressure distribution caused by uneven temperature distribution. Furthermore, cooling the low-temperature zone at a slower rate allows the plastic to maintain a relatively high temperature for a certain period, promoting plastic flow within that zone.

[0197] For example, the injection molding machine can individually control the cooling rate of each sub-mold in the mold. For example, if sub-mold A is a low-temperature region, the cooling rate of sub-mold A can be indirectly changed by altering the rate / temperature of the coolant flowing into sub-mold A.

[0198] In summary, altering the cooling rate of the low-temperature region during the pressure holding stage, allowing it to cool at a slower rate, can help balance the overall temperature of the plastic product, resolve uneven pressure distribution caused by uneven temperature distribution, and improve the quality of the plastic product.

[0199] Based on the same inventive concept, embodiments of this application provide an injection control system for an injection molding machine, including:

[0200] The acquisition module 801 is used to acquire relevant information, actual injection pressure, timestamp information, pressure power supply limit, flow curve, first preset ratio, second preset ratio, first cooling rate, second cooling rate, preset quantity and temperature distribution; the memory 802 is used to store the program of the injection control method of the injection molding machine for any of the above.

[0201] The processor 803 is a program in memory that can be loaded and executed by the processor to implement any of the above-mentioned injection molding machine injection control methods.

[0202] In summary, the injection strategy is updated and executed based on the actual injection pressure of the injection molding machine and the corresponding injection stage. This method allows the injection strategy to be adjusted according to the requirements of different injection stages, ensuring that the injection strategy always meets the needs and effectively improving the quality of plastic products.

[0203] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0204] This application provides a computer-readable storage medium storing a computer program that can be loaded by a processor and executed as an injection control method for an injection molding machine.

[0205] Computer storage media include, for example, USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and other media that can store program code.

[0206] Based on the same inventive concept, embodiments of this application provide a smart terminal, including a memory and a processor, wherein the memory stores a computer program that can be loaded by the processor and executed to control the injection molding of an injection molding machine.

[0207] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0208] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Any feature disclosed in this specification (including the abstract and drawings) may be replaced by other equivalent or similar features unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is only one example of a series of equivalent or similar features.

Claims

1. A method for controlling injection molding in an injection molding machine, characterized in that, The method includes: Based on relevant information about the plastic product, obtain the injection molding strategy corresponding to the relevant information, including the material, structure, and dimensions of the plastic product; During the process of the injection molding machine working according to the injection strategy, the actual injection pressure of the injection molding machine is obtained; Based on the actual injection pressure and the corresponding injection stage, the injection strategy is updated and executed, wherein the injection stage includes a filling stage, a holding stage, and a cooling stage. The step of updating and executing the injection strategy based on the actual injection pressure and the corresponding injection stage includes: obtaining timestamp information corresponding to the actual injection pressure; searching for the expected injection pressure corresponding to the timestamp information in the injection strategy based on the timestamp information; determining whether the actual injection pressure and the expected injection pressure are consistent; if yes, keeping the injection strategy unchanged and executing the injection strategy; if no, determining the injection stage based on the timestamp information; updating the injection strategy based on the actual injection pressure and the injection stage, and executing the updated injection strategy. The step of updating the injection strategy based on the injection stage and the actual injection pressure includes: when the injection stage is a filling stage, if the actual injection pressure is greater than the expected injection pressure, then updating the injection pressure of the filling stage in the injection strategy according to the difference between the actual injection pressure and the expected injection pressure; if the actual injection pressure is less than the expected injection pressure, then determining whether the actual injection pressure has reached the pressure power limit of the injection molding machine; if not, then updating the injection pressure of the filling stage in the injection strategy according to the difference between the expected injection pressure and the actual injection pressure. Pressure; if yes, determine whether the material of the plastic product is a temperature-sensitive material; if yes, obtain the flowability curve of the plastic product material, the flowability curve being used to represent the mapping relationship between the flowability of the plastic and temperature; obtain the target flowability based on the actual injection pressure and the expected injection duration of the injection stage in the injection strategy; find the target injection temperature corresponding to the target flowability in the flowability curve; update the injection temperature of the filling stage in the injection strategy according to the target injection temperature; if not, extend the duration of the filling stage in the injection strategy according to a first preset ratio; After updating the injection temperature in the injection strategy according to the target injection temperature, the method further includes: obtaining a first cooling rate of the injection molding machine during the holding pressure stage according to the injection strategy; determining the holding pressure temperature of the plastic material according to the material of the plastic product; determining whether the temperature difference between the target injection temperature and the holding pressure temperature is greater than a preset difference; if not, maintaining the holding pressure stage duration in the injection strategy unchanged; if yes, calculating the ratio of the temperature difference to the first cooling rate to obtain the holding pressure duration; extending the holding pressure stage duration in the injection strategy according to the holding pressure duration; and reducing the injection pressure during the holding pressure stage in the injection strategy according to a second preset ratio.

2. The injection control method for an injection molding machine according to claim 1, characterized in that, After reducing the injection pressure during the holding stage of the injection molding strategy according to the second preset ratio, the method further includes: According to the injection molding strategy, the second cooling rate of the injection molding machine during the cooling stage is obtained; Based on the relevant information, the maximum cooling rate of the plastic product during the cooling stage and the critical cooling temperature of the plastic product are obtained, wherein the maximum cooling rate is greater than the second cooling rate. The cooling phase in the injection molding strategy is updated based on the second cooling rate, the maximum cooling rate, and the critical cooling temperature, so that the plastic product is cooled at the second cooling rate at the beginning of the cooling phase, and cooled at the maximum cooling rate when the temperature of the plastic product reaches the critical cooling temperature.

3. The injection control method for an injection molding machine according to claim 2, characterized in that, The method further includes: The temperature distribution of the plastic product is obtained when the temperature of the plastic product has not reached the critical cooling temperature. When the temperature distribution does not meet the preset temperature distribution, the temperature anomaly area in the plastic product is obtained; The temperature anomaly area is then heated. If the temperature in the abnormal temperature zone reaches a preset temperature, the plastic product in the abnormal temperature zone is recycled back into the nozzle of the injection molding machine. The injection molding strategy is updated based on the location of the temperature anomaly area and the temperature distribution.

4. The injection control method for an injection molding machine according to claim 1, characterized in that, The method further includes: The preset conversion formula is called to process the mold temperature data and obtain the ideal injection pressure; Compare whether the difference between the actual injection pressure and the ideal injection pressure is less than a preset difference threshold. If not, then adjust the injection pressure of the injection molding machine in the next filling stage according to the difference between the actual injection pressure and the ideal injection pressure; The preset conversion formula is as follows: ； F represents the ideal injection pressure, and α is a preset conversion coefficient. Let K be the mold temperature at point k on the injection mold. Let S be the distance from the k-th point on the injection mold to the injection port, and let S be the surface area of ​​the injection mold.

5. An injection control system for an injection molding machine, characterized in that, The system includes: The acquisition module is used to acquire relevant information, actual injection pressure, timestamp information, pressure power supply limit, flow curve, first preset ratio, second preset ratio, first cooling rate and ambient temperature; A memory for storing the program of the injection control method for the injection molding machine as described in claim 1; The processor and the program in the memory can be loaded and executed by the processor to implement the injection control method of the injection molding machine as described in claim 1.

6. An injection molding machine, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program that can be loaded by the processor and executed according to any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that, The computer program is stored that can be loaded by a processor and executed according to any one of claims 1 to 4.

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