A method for intelligent locking force pressure relief of a two-plate injection molding machine

Abstract

The present application relates to a kind of two-plate injection molding machine intelligent locking force pressure relief method, it is related to the field of injection molding machine, it includes step 1: detection and record the storage time of multiple injection molding processes, and the storage time average T is calculated according to the storage time of multiple injection molding processes;Step 2: obtain cooling time T1, compare cooling time and storage time average T;Step 30: when storage time average T is less than or equal to cooling time T1, according to cooling time T1 with preset proportion pressure relief valve opening algorithm is calculated and exports locking force;Step 31: when storage time average T is greater than cooling time T1, then through the difference T2 of storage time average T and cooling time T1 is substituted into preset proportion pressure relief valve opening algorithm and exports locking force;Step 4: when locking force reaches preset target pressure relief value, open mold is carried out.This application has the effect that locking force is orderly pressure relief in optimal node and optimal time range.

Description

Technical Field

[0001] This invention relates to the field of injection molding machines, and in particular to an intelligent method for relieving clamping force in a two-platen injection molding machine. Background Technology

[0002] In injection molding machine production, clamping force is the maximum clamping force applied to the mold by the mold clamping mechanism. Its purpose is to counteract the mold expansion force generated when the molten material is injected into the mold cavity during the injection stage. After the mold clamping system completes the mold clamping, the moving mold and the fixed mold plate tightly press the mold together. Clamping force is the core basic force to ensure product molding.

[0003] The main operating procedures of a two-platen injection molding machine include injection, material storage and cooling, followed by pressure release, mold opening, and gate opening. In the current production process, the subsequent mold opening and gate opening can only be performed after the material storage and cooling time has elapsed. The cooling and material storage actions are generally performed in parallel.

[0004] Regarding the aforementioned technologies, adjusting the cycle time of the injection molding machine through conventional adjustment actions has limited adjustment range and results in poor stability of the injection molding machine and the injection molded products, which still needs improvement. Summary of the Invention

[0005] To ensure orderly pressure relief of clamping force within optimal nodes and time ranges, this invention provides an intelligent clamping force relief method for a two-platen injection molding machine. The technical solution is as follows: A method for intelligent clamping force relief in a two-platen injection molding machine includes: Step 1: Detect and record the material storage time of multiple injection molding processes, and calculate the average material storage time T based on the material storage time of multiple injection molding processes; Step 2: Obtain the cooling time T1, and compare the average value T of the cooling time and the storage time; Step 30: When the average storage time T is less than or equal to the cooling time T1, calculate and output the clamping force according to the cooling time T1 using the preset proportional pressure relief valve opening algorithm; Step 31: When the average storage time T is greater than the cooling time T1, the difference T2 between the average storage time T and the cooling time T1 is substituted into the preset proportional pressure relief valve opening algorithm for calculation and output of clamping force. Step 4: Open the mold when the clamping force reaches the preset target pressure relief value.

[0006] By adopting the above technical solution, and by obtaining the average value through multi-mode detection, the random error of the single material storage time is eliminated, ensuring the accuracy of the parameters and ensuring that the clamping force is released in an orderly manner within the optimal node and optimal time range.

[0007] Optionally, the formula for calculating the opening of the proportional pressure relief valve is: ; Where p is the real-time pressure, τ is the time the pressure relief valve has been open, t is the total pressure relief time, a is the target pressure relief value, v0 is the minimum operating voltage, and K p and K d Here, t-τ is the control parameter, and t-τ is the remaining time.

[0008] By adopting the above technical solution, the algorithm integrates proportional control and derivative control to ensure the stability and accuracy of pressure relief; the derivative term is pre-adjusted according to the pressure change rate, while ensuring that the output voltage is greater than the minimum working voltage, so as to ensure that the pressure relief valve is always in working condition.

[0009] Optionally, when the average storage time T is greater than the cooling time T1, it includes: Step 310: Obtain real-time pressure, processing time, difference T2, average storage time T, and minimum operating voltage; Step 311: Based on the real-time pressure, processing time, difference T2, average storage time T, minimum working voltage, and preset control parameters, the output voltage v of the corrected proportional valve is obtained using the proportional relief valve opening algorithm. Step 312: Control the proportional pressure relief valve to output the clamping force at the corrected output voltage v to relieve pressure.

[0010] By adopting the above technical solution, the time difference between material storage and cooling is substituted into the algorithm calculation, so that the output voltage of the proportional pressure relief valve can be adapted to the material storage time requirement; the output voltage is corrected in real time by the algorithm to realize the dynamic adjustment of the opening degree of the pressure relief valve.

[0011] Optionally, before controlling the proportional pressure relief valve to output the clamping force at the output voltage v, the following is included: Step 3120: Determine the pressure relief end time according to the preset pressure relief time; Step 3121: Determine the end time of material storage based on the average storage time T; Step 3122: Compare the pressure relief end time with the material storage end time and obtain the end difference value. The end difference value is less than the preset interval time.

[0012] By adopting the above technical solution, a time matching verification between pressure relief and material storage is added before the pressure relief is executed, ensuring the accuracy and timeliness of the pressure relief process and the material storage process.

[0013] Optionally, when the average storage time T is less than or equal to the cooling time T1, it includes: Step 300: Obtain the real-time pressure, processing time, cooling time, average storage time, and minimum operating voltage; Step 301: Generate a linear curve using a proportional pressure relief valve opening algorithm based on real-time pressure, processing time, cooling time, average storage time, minimum operating voltage, preset control parameters, and preset pressure relief time. Step 302: Obtain the corrected output voltage v from the linear curve graph; Step 303: Use the cooling time T1 as the pressure relief valve's pressure relief end time, and determine the pressure relief start time based on the cooling time T1 and the preset pressure relief time; Step 304: Control the output voltage v of the proportional pressure relief valve to be output at the pressure relief start time.

[0014] By adopting the above technical solution, the output change trend can be visualized by generating a linear curve of output voltage and pressure relief time, making the output results simpler and more accurate. At the same time, the cooling time is used as the pressure relief end time to ensure that pressure relief is started and completed at the optimal node of the injection molding process.

[0015] In summary, this application includes at least one of the following beneficial technical effects: By detecting the material storage time in multiple injection molding cycles and taking the arithmetic average, the random error of the material storage time in a single cycle is eliminated; Based on the numerical relationship between the average storage time and the cooling time, two pressure relief control conditions are defined and corresponding algorithms are applied to calculate the pressure relief, making it suitable for various molds and materials. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of an intelligent clamping force relief method for a two-platen injection molding machine. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0018] This application discloses an intelligent clamping force relief method for a two-platen injection molding machine.

[0019] Reference Figure 1 A method for intelligent clamping force relief in a two-platen injection molding machine, comprising: Step 1: Detect and record the material storage time of multiple injection molding processes, and calculate the average material storage time T based on the material storage time of multiple injection molding processes.

[0020] Material storage time refers to the actual material storage time of a two-platen injection molding machine.

[0021] The average storage time T refers to the average value obtained by calculating the storage time after multiple recordings of the material storage time after injection molding. In this embodiment, the number of recordings is 3.

[0022] The material storage time for each of the three injection molding processes is obtained by the sensing device on the injection molding machine, and the average material storage time for the three molds is calculated.

[0023] Step 2: Obtain the cooling time T1 and compare the average value T of the cooling time and the storage time.

[0024] Cooling time refers to the actual time required for the product to cool down after injection molding.

[0025] The cooling time varies for different products. The cooling time is determined by prior experiments. By comparing the average cooling time and storage time, two scenarios are identified: the first is that the cooling time is less than the average storage time, and the second is that the cooling time is greater than the average storage time.

[0026] Step 30: When the average storage time T is less than or equal to the cooling time T1, calculate and output the clamping force according to the preset proportional pressure relief valve opening algorithm based on the cooling time T1.

[0027] When the cooling time is less than the average storage time, it falls under the first case. In this case, the cooling time is substituted into the formula of the proportional pressure relief valve opening algorithm to calculate and output the clamping force.

[0028] Step 31: When the average storage time T is greater than the cooling time T1, the difference T2 between the average storage time T and the cooling time T1 is substituted into the preset proportional pressure relief valve opening algorithm for calculation and output of clamping force.

[0029] When the average storage time T is greater than the cooling time T1, it falls under the second case. It is necessary to first calculate the difference T2 between the average storage time and the cooling time, substitute the difference T2 into the proportional pressure relief valve opening algorithm, and then output the clamping force.

[0030] Step 4: Open the mold when the clamping force reaches the preset target pressure relief value.

[0031] The target pressure relief value refers to the force required to press the mold tightly together by the moving mold and the fixed mold plate after the mold closing system has completed the mold closing process.

[0032] When the clamping force reaches the target pressure relief value, the proportional pressure relief valve is controlled to open the mold.

[0033] The formula for calculating the opening of a proportional pressure relief valve is: ; Where v is the output voltage, p is the real-time pressure, τ is the time the pressure relief valve has been open, t is the total pressure relief time, a is the target pressure relief value, v0 is the minimum operating voltage, and K p and K d Here, t-τ is the control parameter, and t-τ is the remaining time.

[0034] Referring to the formula, based on the real-time pressure p, the time τ, the total pressure relief time t, the target pressure relief value a, the minimum operating voltage v0, and the control parameter K... p and K d The output voltage v can be derived.

[0035] When the average storage time T is greater than the cooling time T1, including: Step 310: Obtain real-time pressure, processing time, difference T2, average storage time T, and minimum operating voltage.

[0036] Real-time pressure refers to the pressure inside the injection molding machine that is recorded in real time by a pressure sensor installed in the proportional pressure relief valve.

[0037] The execution time refers to the difference between the time when the proportional pressure relief valve starts to operate and the current time.

[0038] Minimum operating voltage refers to the lowest voltage value required for the proportional pressure relief valve to operate.

[0039] It acquires real-time data such as pressure, processing time, difference T2, and average storage time T.

[0040] Step 311: Based on the real-time pressure, processing time, difference T2, average storage time T, minimum working voltage, and preset control parameters, the output voltage v of the corrected proportional valve is obtained using the proportional relief valve opening algorithm.

[0041] The preset control parameters refer to the proportional coefficients Kp and Kd required for the proportional relief valve opening algorithm. These parameters are variables that can be manually adjusted.

[0042] In the second case, the difference T 2代入 The total pressure relief time t in the formula is used to calculate and obtain the corrected output voltage v of the proportional valve.

[0043] Step 312: Control the proportional pressure relief valve to output the clamping force at the corrected output voltage v to relieve pressure.

[0044] The control proportional pressure relief valve will output voltage and clamping force to relieve pressure based on the calculated voltage value.

[0045] Before controlling the proportional pressure relief valve to output clamping force at output voltage v, the following is included: Step 3120: Determine the pressure relief end time according to the preset pressure relief time.

[0046] The pressure relief time refers to the time period required for the proportional pressure relief valve to perform its pressure relief action.

[0047] The pressure relief end time refers to the time it takes for the proportional pressure relief valve to finish its pressure relief action.

[0048] The last moment of the pressure relief time period can be taken as the end time of the pressure relief action.

[0049] Step 3121: Determine the end time of material storage based on the average storage time T.

[0050] The material storage end time refers to the time period required for the injection molding machine to perform the material storage action.

[0051] The material storage end time refers to the time when the injection molding machine finishes the material storage action.

[0052] The last moment of the storage time period can be used as the end time of the storage operation.

[0053] Step 3122: Compare the pressure relief end time with the material storage end time and obtain the end difference value. The end difference value is less than the preset interval time.

[0054] The end difference refers to the time difference between the end time of material storage and the end time of pressure relief, where the end time of material storage is longer than the end time of pressure relief.

[0055] The interval time refers to the preset time value between the pressure relief end time and the material storage end time, which is used to determine the pressure relief start time.

[0056] The pressure relief end time is compared with the material storage end time, and the difference between the two is the end difference value. The end difference value is less than the preset interval time. If the interval time is 3 seconds, the proportional pressure relief valve is controlled to complete the pressure relief action 3 seconds before the material storage end time.

[0057] When the average storage time T is less than or equal to the cooling time T1, including: Step 300: Obtain the real-time pressure, processing time, cooling time, average storage time, and minimum operating voltage.

[0058] It acquires real-time data such as pressure, processing time, difference T2, and average storage time T.

[0059] Step 301: Generate a linear curve using a proportional pressure relief valve opening algorithm based on real-time pressure, processing time, cooling time, average storage time, minimum operating voltage, preset control parameters, and preset pressure relief time.

[0060] The pressure relief time refers to the time it takes for the proportional pressure relief valve to perform its pressure relief action.

[0061] A linear curve graph is a graph showing the linear trend of output voltage over time.

[0062] In the first scenario, the cooling time and depressurization time are substituted into the total depressurization time t in the formula to calculate and obtain the corrected proportional valve output voltage v and its linear curve. For example, assuming a storage time of 20 seconds, a cooling time of 15 seconds, and a depressurization time of 2 seconds, the normal three-action cycle would take 20 + 2 = 22 seconds. With this solution, depressurization will initiate after cooling and complete before the end of storage. That is, it will initiate after 15 seconds and complete before 20 seconds, using flexible proportional depressurization. Depressurization is completed before storage, and the three-action cycle takes 20 seconds. This saves time and, through linear depressurization, improves product yield.

[0063] Step 302: Obtain the corrected output voltage v from the linear curve graph.

[0064] Adjust the output voltage that matches the time in the linear curve graph, and execute the output based on the output voltage.

[0065] Step 303: Use the cooling time T1 as the pressure relief valve's pressure relief end time, and determine the pressure relief start time based on the cooling time T1 and the preset pressure relief time.

[0066] The proportional pressure relief valve is controlled by taking the end time of the cooling time as the pressure relief end time, and by working backward from the cooling time and pressure relief time to determine the pressure relief start time.

[0067] Step 304: Control the output voltage v of the proportional pressure relief valve to be output at the pressure relief start time.

[0068] The final control proportional pressure relief valve outputs voltage v at the pressure relief start time.

[0069] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for intelligent clamping force relief in a two-platen injection molding machine, characterized in that, include: Step 1: Detect and record the material storage time of multiple injection molding processes, and calculate the average material storage time T based on the material storage time of multiple injection molding processes; Step 2: Obtain the cooling time T1, and compare the average value T of the cooling time and the storage time; Step 30: When the average storage time T is less than or equal to the cooling time T1, calculate and output the clamping force according to the cooling time T1 using the preset proportional pressure relief valve opening algorithm; Step 31: When the average storage time T is greater than the cooling time T1, the difference T2 between the average storage time T and the cooling time T1 is substituted into the preset proportional pressure relief valve opening algorithm for calculation and output of clamping force. Step 4: Open the mold when the clamping force reaches the preset target pressure relief value.

2. The method for intelligent clamping force relief in a two-platen injection molding machine according to claim 1, characterized in that, The formula for calculating the opening of a proportional pressure relief valve is: ； Where p is the real-time pressure, τ is the time the pressure relief valve has been open, t is the total pressure relief time, a is the target pressure relief value, v0 is the minimum operating voltage, and K p and K d Here, t-τ is the control parameter, and t-τ is the remaining time.

3. The method for intelligent clamping force relief in a two-platen injection molding machine according to claim 2, characterized in that, When the average storage time T is greater than the cooling time T1, including: Step 310: Obtain real-time pressure, processing time, difference T2, average storage time T, and minimum operating voltage; Step 311: Based on the real-time pressure, processing time, difference T2, average storage time T, minimum working voltage, and preset control parameters, the output voltage v of the corrected proportional valve is obtained using the proportional relief valve opening algorithm. Step 312: Control the proportional pressure relief valve to output the clamping force at the corrected output voltage v to relieve pressure.

4. The method for intelligent clamping force relief in a two-platen injection molding machine according to claim 3, characterized in that, Before controlling the proportional pressure relief valve to output clamping force at output voltage v, the following is included: Step 3120: Determine the pressure relief end time according to the preset pressure relief time; Step 3121: Determine the end time of material storage based on the average storage time T; Step 3122: Compare the pressure relief end time with the material storage end time and obtain the end difference value. The end difference value is less than the preset interval time.

5. The method for intelligent clamping force relief in a two-platen injection molding machine according to claim 2, characterized in that, When the average storage time T is less than or equal to the cooling time T1, including: Step 300: Obtain the real-time pressure, processing time, cooling time, average storage time, and minimum operating voltage; Step 301: Generate a linear curve using a proportional pressure relief valve opening algorithm based on real-time pressure, processing time, cooling time, average storage time, minimum operating voltage, preset control parameters, and preset pressure relief time. Step 302: Obtain the corrected output voltage v from the linear curve graph; Step 303: Use the cooling time T1 as the pressure relief valve's pressure relief end time, and determine the pressure relief start time based on the cooling time T1 and the preset pressure relief time; Step 304: Control the output voltage v of the proportional pressure relief valve to be output at the pressure relief start time.

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