A method for controlling pressure on thin edges of automotive interior injection molded parts

Abstract

The present invention relates to the field of automobile interiors and discloses a pressure control method for thin edges of automobile interior injection-molded parts. The method comprises area division, data acquisition, data recording and preprocessing, feature extraction, pressure loss analysis, pressure loss calibration and adjustment execution. The method divides the thin edges of plastic parts into several sub-areas according to wall thickness distribution, and preprocesses the process parameters of the injection molding process of the thin edges of the plastic parts in each target sub-area for monitoring and acquisition. The preprocessed parameters are subjected to feature extraction and parallel analysis, and then a comprehensive analysis is performed to calculate a comprehensive pressure loss evaluation index of the thin edges and a pressure calibration coefficient, thereby realizing an evaluation of the overall pressure loss of the thin edges of the plastic parts and pressure loss calibration. The method is conducive to solving the problem of inaccurate pressure monitoring of the thin edges during the injection molding process, and takes into account the influence of changes in wall thickness on melt flow and pressure distribution, thereby realizing more refined pressure control and reducing quality defects caused by improper pressure control during the trial mold.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile interior decoration, and more particularly to a method for controlling the pressure of thin edges of automobile interior decoration injection molding parts. Background Art

[0002] With the rapid development of the automobile industry, people have higher and higher requirements for the quality and appearance of automobile interiors. As an important part of automobile interiors, the quality of injection molded parts directly affects the overall quality of the car. However, during the injection molding process, problems such as insufficient pressure and incomplete filling are prone to occur in thin-edge parts, which not only affect the appearance quality of the injection molded parts, but may also lead to performance degradation. The traditional pressure control method is mainly achieved by adjusting the pressure and speed of the injection molding machine, but this method is not ideal for pressure control of thin-edge parts. With the continuous development of computer technology and sensor technology, a pressure control method for thin edges of automobile interior injection molded parts has emerged. It uses pressure control based on machine vision and pressure control based on neural networks, monitors the pressure changes during the injection molding process in real time, and automatically adjusts the pressure and speed of the injection molding machine according to the monitoring results, thereby achieving effective control of thin-edge pressure.

[0003] However, the above process still has the following disadvantages:

[0004] First, existing pressure control methods for the thin edges of automotive interior injection molded parts are not accurate enough in monitoring the pressure of the thin edges during the injection molding process. They fail to consider the injection defects caused by uneven pressure distribution on the thin edges of the plastic parts, and are unable to accurately control the pressure at different locations on the thin edges of the plastic parts.

[0005] Secondly, there is a lack of pressure control at different locations according to the distribution of wall thickness changes, and a lack of accurate pressure adjustment from the perspective of uneven pressure distribution. This will lead to quality defects due to improper pressure control during the mold trial and the inability to stabilize product quality. Summary of the Invention

[0006] In order to overcome the above-mentioned defects of the prior art, the present invention provides a method for controlling the thin edge pressure of an automobile interior injection molded part to solve the problems existing in the above-mentioned background technology.

[0007] The present invention provides the following technical solution: a method for controlling the thin edge pressure of an automobile interior injection molded part, comprising:

[0008] S1: Divide the thin edge of the plastic part into several sub-areas according to the wall thickness distribution and number them 1, 2, 3, ... m. By installing sensors on the injection molding machine, the injection molding process parameters of the thin edge of the plastic part in each target sub-area are monitored and collected in real time. The collected injection molding process parameters of the thin edge of the plastic part in each target sub-area are transmitted to S2;

[0009] S2: Using a built-in recorder of the injection molding machine, the process parameters of the thin-edge injection molding process of the plastic parts in each target sub-region are recorded respectively, and then the process parameters of the thin-edge injection molding process of the plastic parts in each target sub-region are pre-processed in parallel, and the pre-processed process parameters of the thin-edge injection molding process of the plastic parts in each target sub-region are transmitted to S3;

[0010] S3: By extracting data features of the process parameters of the thin edge injection molding process of the plastic part in each target sub-region, the temperature fluctuation value, melt pressure loss and acceleration pressure loss in each target sub-region are obtained respectively, and the extracted temperature fluctuation value, melt pressure loss and acceleration pressure loss in each target sub-region are transmitted to S4;

[0011] S4: Parallel analysis is performed on the extracted temperature fluctuation values, melt pressure loss, and acceleration pressure loss in each target sub-region, and the injection pressure loss value of the sub-region is calculated, and the injection pressure loss value of the sub-region is transmitted to S5;

[0012] S5: The injection pressure loss values ​​of the sub-regions analyzed in each target sub-region are comprehensively analyzed and a thin edge comprehensive pressure loss evaluation index is calculated. The thin edge comprehensive pressure loss evaluation index evaluates the overall loss of injection pressure at the thin edge of the plastic part, and the thin edge comprehensive pressure loss evaluation index is transmitted to S6;

[0013] S6: Calculate the pressure calibration coefficient based on the thin edge comprehensive pressure loss evaluation index, calibrate the thin edge injection pressure loss through the pressure calibration coefficient, control the injection pressure to make the thin edge fill uniformly, and transmit the pressure control adjustment execution instruction to S7;

[0014] S7: Execute the pressure control adjustment execution instruction, adjust the injection molding process parameters, and generate a pressure adjustment stop execution instruction.

[0015] Preferably, the area division method of S1 is:

[0016] According to the distribution of wall thickness variation of the thin edge of the plastic part, it is divided into different gradient areas from thin to thick, and the wall thickness of each area is numbered in sequence from thin to thick;

[0017] The data collection method of S1 is:

[0018] According to the number of areas divided by the thin-edge wall thickness distribution of the plastic part, a corresponding number of types of sensors are arranged on the injection molding machine to cover each target sub-area, and the process parameters of the thin-edge injection molding process of the plastic part in each target sub-area are measured and collected, including temperature, pressure, holding time and speed. The types of sensors include pressure sensors, temperature sensors and speed sensors.

[0019] Preferably, the S2 automatically records the process parameters of the thin-edge injection molding process of plastic parts in each target sub-area in chronological order by setting the data recording time of each area in the built-in recorder, and then stores them in the database according to the divided areas. The specific operation of the parallel preprocessing of the process parameters of the thin-edge injection molding process of plastic parts in each target sub-area is: simultaneously performing data cleaning, filtering and removing abnormal values ​​on the process parameters of the thin-edge injection molding process of plastic parts in multiple target sub-areas.

[0020] Preferably, the step S3 extracts the characteristics of the pre-processed thin edge injection molding process parameters of each target sub-region, obtains characteristic parameters that affect the injection molding pressure change of the thin edge of the plastic part, and calculates them;

[0021] The temperature fluctuation value is obtained by periodically recording the actual value of the mold temperature T from the beginning of injection molding. a1 , T a2 ,Λ,T an , actual value of melt temperature T b1 , T b2 ,Λ,T bn And the actual value of the ambient temperature T c1 , T c2 ,Λ,T cn , the calculation formula for temperature fluctuation value is T ai Indicates recording the actual value of the mold temperature for the i-th time, T bi Indicates recording the actual value of the melt temperature for the i-th time, T ci Indicates recording the actual value of the i-th ambient temperature, Indicates the average value of the mold temperature recorded n times, Indicates the average value of the melt temperature recorded n times, Indicates the average value of the ambient temperature recorded n times;

[0022] The melt pressure loss is used to monitor the pressure loss during melt friction during the injection molding process and record the actual value of the melt temperature T for the i-th time. bi , the calculation formula for melt pressure loss is L represents the length of the melt flow channel, represents the average flow rate of the melt during injection molding, D represents the flow channel diameter, u0 represents the viscosity of the melt at the reference temperature T0, t0 represents the reference temperature of the melt, α represents the temperature index, and 0.3≤α≤0.6. The specific value is adjusted according to experimental data;

[0023] The acceleration pressure loss is used to monitor the pressure loss caused by the acceleration and deceleration of the melt in the flow channel during the injection molding process. The melt inlet velocity v1 and outlet velocity v2 are recorded respectively. The calculation formula for the acceleration pressure loss is: ρ represents the density of the melt.

[0024] Preferably, the S4 simultaneously analyzes the sub-region injection pressure loss values ​​in multiple target sub-regions through the temperature fluctuation value ΔT, melt pressure loss ΔP1 and acceleration pressure loss ΔP2 in each target sub-region. The calculation formula of the sub-region injection pressure loss value is Δp j =(ΔP1+ΔP2+P′) ΔT , P′ represents the local pressure loss, and the sub-region injection pressure loss value calculated for each target sub-region is transmitted to S5.

[0025] Preferably, the S5 monitors and evaluates the overall loss state of injection pressure through the thin edge comprehensive pressure loss evaluation index. The formula for calculating the thin edge comprehensive pressure loss evaluation index is: Δp1, Δp2, Δp3, Λ, Δp m Indicates the injection pressure loss value of the 1st, 2nd, 3rd...mth target sub-region, Δp j represents the injection pressure loss value of the jth sub-region, It represents the average value of the injection pressure loss values ​​of m sub-areas.

[0026] Preferably, the S6 compares the thin edge comprehensive pressure loss evaluation index with a preset pressure loss threshold to calculate the pressure calibration coefficient: S represents the thin edge comprehensive pressure loss evaluation index, s′ represents the preset pressure loss threshold. When the pressure calibration coefficient u is in the range of (0,1), it means that the pressure loss in the current injection molding process is within the controllable range, the quality of the injection molded parts meets the design requirements, and there is no need to control and adjust the pressure. When the pressure calibration coefficient u is in the range of [1, +∞), it means that the pressure loss in the injection molding process exceeds the controllable range. At this time, the pressure loss will have an adverse effect on the quality of the injection molded parts. The injection molding process needs to be controlled and adjusted, and the pressure control adjustment execution instruction is immediately generated and transmitted to S7.

[0027] Preferably, the S7 is used to receive and execute the pressure control adjustment execution instruction, adjust the injection molding process parameters, and monitor the pressure changes during the adjustment process in real time. When the pressure loss is detected to be within the controllable range, the pressure adjustment stop execution instruction is immediately triggered, and a pressure adjustment stop execution instruction is sent to S6, and the execution behavior is stopped.

[0028] Technical effects and advantages of the present invention:

[0029] The present invention divides the thin edge of the plastic part into several sub-areas according to the wall thickness distribution, and installs sensors on the injection molding machine to monitor and collect the injection molding process parameters of the thin edge of the plastic part in each target sub-area in real time, and records the injection molding process parameters of the thin edge of the plastic part in each target sub-area through the built-in recorder of the injection molding machine. Then, the injection molding process parameters of the thin edge of the plastic part in each target sub-area are pre-processed in parallel, which is conducive to solving the problem of inaccurate pressure monitoring of the thin edge during the injection molding process, takes into account the influence of the change of wall thickness on the melt flow and pressure distribution, thereby achieving more refined pressure control, reducing injection defects caused by uneven pressure distribution, and extracting and analyzing the characteristics of the thin edge of the plastic part in each target sub-area. After analysis, the process parameters of the thin-edge injection molding process of the target sub-area plastic part are comprehensively analyzed to obtain the thin-edge comprehensive pressure loss evaluation index to evaluate the overall loss of injection pressure at the thin edge of the plastic part. The thin-edge injection molding pressure loss and pressure control adjustment execution operations are calibrated through the calculated pressure calibration coefficient. By calculating the pressure loss value in each area, the pressure demand of each area can be more accurately predicted and adjusted, the injection pressure can be automatically controlled, and a more uniform and stable pressure distribution adjustment can be achieved, which is conducive to reducing quality defects caused by improper pressure control during the trial mold process, reducing the number of trial molds and production costs, thereby improving production efficiency and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A diagram showing the steps of the method of the present invention.

[0031] Figure 2 This is a system structure diagram of the present invention. DETAILED DESCRIPTION

[0032] The technical solutions of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. In addition, the forms of the various structures described in the following embodiments are merely examples. The thin edge pressure control method of an automobile interior injection molded part involved in the present invention is not limited to the various structures described in the following embodiments. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] The present invention provides a method for controlling the thin edge pressure of an automobile interior injection molded part, comprising:

[0034] S1: Divide the thin edge of the plastic part into several sub-areas according to the wall thickness distribution and number them as 1, 2, 3...m. By installing sensors on the injection molding machine, the injection molding process parameters of the thin edge of the plastic part in each target sub-area are monitored and collected in real time, and the collected injection molding process parameters of the thin edge of the plastic part in each target sub-area are transmitted to S2.

[0035] In this embodiment, the area division method of S1 is:

[0036] According to the distribution of wall thickness variation of the thin edge of the plastic part, it is divided into different gradient areas from thin to thick, and the wall thickness of each area is numbered in sequence from thin to thick;

[0037] The data collection method of S1 is:

[0038] According to the number of areas divided by the thin-edge wall thickness distribution of the plastic part, a corresponding number of types of sensors are arranged on the injection molding machine to cover each target sub-area, and the process parameters of the thin-edge injection molding process of the plastic part in each target sub-area are measured and collected, including temperature, pressure, holding time and speed. The types of sensors include pressure sensors, temperature sensors and speed sensors.

[0039] It should be noted that the specific operation process of S1 area division is: use 3D scanning equipment to obtain the precise wall thickness data of the thin edge of the plastic part, use CAD software to process the wall thickness data, identify the wall thickness change law, and then divide the thin edge of the plastic part into multiple gradient areas from thin to thick according to the wall thickness change law. The wall thickness change in each area should be relatively uniform. Number each area, starting from the area with the thinnest wall thickness, and number them in sequence as 1, 2, 3...m. By installing sensors at representative positions in each gradient area, the injection molding process parameters of the area can be covered.

[0040] S2: The thin-edge injection molding process parameters of the plastic parts in each target sub-area are recorded separately through the built-in recorder of the injection molding machine, and then the thin-edge injection molding process parameters of the plastic parts in each target sub-area are preprocessed in parallel, and the preprocessed thin-edge injection molding process parameters of the plastic parts in each target sub-area are transmitted to S3.

[0041] In this embodiment, S2 automatically records the process parameters of the thin-edge injection molding process of plastic parts in each target sub-area in chronological order by setting the data recording time of each area in the built-in recorder, and then stores them in the database according to the divided areas. The specific operation of the parallel preprocessing of the process parameters of the thin-edge injection molding process of plastic parts in each target sub-area is: data cleaning, filtering and removal of abnormal values ​​of the process parameters of the thin-edge injection molding process of plastic parts in multiple target sub-areas at the same time.

[0042] It should be noted that the S2 can optionally have a built-in recorder with programmable functions and supports multi-channel data acquisition, automatically starting and stopping recording according to a preset schedule.

[0043] S3: By extracting data features of the process parameters of the thin-edge injection molding process of the plastic parts in each target sub-area, the temperature fluctuation value, melt pressure loss and acceleration pressure loss in each target sub-area are obtained respectively, and the extracted temperature fluctuation value, melt pressure loss and acceleration pressure loss in each target sub-area are transmitted to S4.

[0044] In this embodiment, S3 extracts the characteristics of the pre-processed thin edge injection molding process parameters of each target sub-region, obtains the characteristic parameters that affect the injection molding pressure change of the thin edge of the plastic part, and calculates them;

[0045] The temperature fluctuation value is obtained by regularly recording the actual mold temperature T from the beginning of injection molding. a1 , T a2 ,Λ,T an , actual value of melt temperature T b1 , T b2 ,Λ,T bn And the actual value of the ambient temperature T c1 , T c2 ,Λ,T cn , the calculation formula for temperature fluctuation value is T ai Indicates recording the actual value of the mold temperature for the i-th time, T bi Indicates recording the actual value of the melt temperature for the i-th time, T ci Indicates recording the actual value of the i-th ambient temperature, Indicates the average value of the mold temperature recorded n times, Indicates the average value of the melt temperature recorded n times, Indicates the average value of the ambient temperature recorded n times;

[0046] Melt pressure loss is used to monitor the pressure loss during melt friction during the injection molding process and record the actual value of the melt temperature T for the i-th time. bi , the calculation formula for melt pressure loss is L represents the length of the melt flow channel, represents the average flow rate of the melt during injection molding, D represents the flow channel diameter, u0 represents the viscosity of the melt at the reference temperature T0, t0 represents the reference temperature of the melt, α represents the temperature index, and 0.3≤α≤0.6. The specific value is adjusted according to experimental data;

[0047] Acceleration pressure loss is used to monitor the pressure loss caused by acceleration and deceleration of the melt in the flow channel during the injection molding process. The melt inlet velocity v1 and outlet velocity v2 are recorded respectively. The calculation formula for the acceleration pressure loss is: ρ represents the density of the melt.

[0048] S4: The temperature fluctuation values, melt pressure loss, and acceleration pressure loss extracted in each target sub-region are analyzed in parallel, and the injection pressure loss value of the sub-region is calculated, and the injection pressure loss value of the sub-region is transmitted to S5.

[0049] In this embodiment, S4 simultaneously analyzes the injection pressure loss values ​​of the sub-regions in multiple target sub-regions through the temperature fluctuation value ΔT, melt pressure loss ΔP1 and acceleration pressure loss ΔP2 in each target sub-region. The calculation formula of the injection pressure loss value of the sub-region is Δp j =(ΔP1+ΔP2+P′) ΔT , P′ represents the local pressure loss, and the sub-region injection pressure loss value calculated for each target sub-region is transmitted to S5.

[0050] It should be noted that the specific analysis process of the local pressure loss P′ in S4 is as follows:

[0051] S41: During the injection molding process, determine the local loss areas, including runner corners, dead corners, cross-section changes, and areas of geometric shape changes;

[0052] S42: Record the average melt flow velocity v′ and melt density ρ′ in the local loss area;

[0053] S43: Calculate the local pressure loss as K represents the local loss coefficient, and its specific value is calculated and verified by experimental data.

[0054] S5: The sub-region injection pressure loss values ​​analyzed in each target sub-region are comprehensively analyzed and a thin edge comprehensive pressure loss evaluation index is calculated. The thin edge comprehensive pressure loss evaluation index evaluates the overall loss of injection pressure at the thin edge of the plastic part, and the thin edge comprehensive pressure loss evaluation index is transmitted to S6.

[0055] In this embodiment, S5 monitors and evaluates the overall injection pressure loss state through the thin edge comprehensive pressure loss evaluation index. The formula for calculating the thin edge comprehensive pressure loss evaluation index is: Δp1, Δp2, Δp3, Λ, Δp m Indicates the injection pressure loss value of the 1st, 2nd, 3rd...mth target sub-region, Δp j represents the injection pressure loss value of the jth sub-region, It represents the average value of the injection pressure loss values ​​of m sub-areas.

[0056] S6: Calculate the pressure calibration coefficient based on the thin edge comprehensive pressure loss evaluation index, calibrate the thin edge injection pressure loss through the pressure calibration coefficient, control the injection pressure to make the thin edge fill uniformly, and transmit the pressure control adjustment execution instruction to S7.

[0057] In this embodiment, S6 compares the thin edge comprehensive pressure loss evaluation index with the preset pressure loss threshold and calculates the pressure calibration coefficient: S represents the thin edge comprehensive pressure loss evaluation index, s′ represents the preset pressure loss threshold. When the pressure calibration coefficient u is in the range of (0,1), it means that the pressure loss in the current injection molding process is within the controllable range, the quality of the injection molded parts meets the design requirements, and there is no need to control and adjust the pressure. When the pressure calibration coefficient u is in the range of [1, +∞), it means that the pressure loss in the injection molding process exceeds the controllable range. At this time, the pressure loss will have an adverse effect on the quality of the injection molded parts. The injection molding process needs to be controlled and adjusted, and the pressure control adjustment execution instruction is immediately generated and transmitted to S7.

[0058] S7: Execute the pressure control adjustment execution instruction, adjust the injection molding process parameters, and generate a pressure adjustment stop execution instruction.

[0059] In this embodiment, S7 is used to receive and execute the pressure control adjustment execution instruction, adjust the injection molding process parameters, and monitor the pressure changes during the adjustment process in real time. When the pressure loss is detected to be within the controllable range, the pressure adjustment stop execution instruction is immediately triggered, and a pressure adjustment stop execution instruction is sent to S6, and the execution behavior is stopped.

[0060] It should be specifically explained that the S7's pressure control adjustment execution process includes: increasing the injection pressure or holding pressure to compensate for pressure loss; adjusting the melt temperature and mold temperature to improve the fluidity and cooling effect of the plastic; and using pressure sensors to monitor the pressure changes and adjustments of the injection molding process in real time, and transmitting the pressure control results to the database for storage, providing managers with a pressure control result query function.

[0061] like Figure 2 The embodiment shown provides an implementation system corresponding to a method for controlling thin-edge pressure of automotive interior injection-molded parts, including an area division module, a data acquisition module, a data recording and preprocessing module, a feature extraction module, a pressure loss analysis module, a comprehensive analysis module, a pressure loss calibration module, and an adjustment execution module. The area division module is connected to the data acquisition module, the data acquisition module is connected to the data recording and preprocessing module, the data recording and preprocessing module is connected to the feature extraction module, the feature extraction module is connected to the pressure loss analysis module, the pressure loss analysis module is connected to the comprehensive analysis module, the comprehensive analysis module is connected to the pressure loss calibration module, and the pressure loss calibration module is connected to the adjustment execution module.

[0062] The area division module divides the thin edge of the plastic part into several sub-areas according to the wall thickness distribution and numbers them as 1, 2, 3...m;

[0063] The data acquisition module monitors and collects the process parameters of the thin edge injection molding process of each target sub-area plastic part in real time by installing sensors on the injection molding machine;

[0064] The data recording and preprocessing module records the process parameters of the thin edge injection molding process of the plastic parts in each target sub-region through the built-in recorder of the injection molding machine, and then preprocesses the process parameters of the thin edge injection molding process of the plastic parts in each target sub-region in parallel;

[0065] The feature extraction module extracts data features of the process parameters of the thin edge injection molding process of the plastic parts in each target sub-region, and obtains the temperature fluctuation value, melt pressure loss and acceleration pressure loss in each target sub-region respectively;

[0066] The pressure loss analysis module analyzes the extracted temperature fluctuation values, melt pressure loss, and acceleration pressure loss in each target sub-region in parallel, and calculates the injection pressure loss value of the sub-region;

[0067] The comprehensive analysis module comprehensively analyzes the injection pressure loss values ​​of the sub-regions analyzed in each target sub-region and calculates a thin edge comprehensive pressure loss evaluation index, which evaluates the overall loss of injection pressure at the thin edge of the plastic part.

[0068] The pressure loss calibration module calculates a pressure calibration coefficient based on the thin edge comprehensive pressure loss evaluation index, calibrates the thin edge injection molding pressure loss using the pressure calibration coefficient, and controls the injection molding pressure to ensure uniform filling of the thin edge;

[0069] The adjustment execution module executes the pressure control adjustment execution instruction, adjusts the injection molding process parameters, and generates a pressure adjustment stop execution instruction.

[0070] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0071] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A method for controlling the thin edge pressure of an automobile interior injection molded part, characterized in that: The following steps are involved: S1: Divide the thin edge of the plastic part into several sub-areas according to the wall thickness distribution and number them 1, 2, 3, ... m. By installing sensors on the injection molding machine, the injection molding process parameters of the thin edge of the plastic part in each target sub-area are monitored and collected in real time. The collected injection molding process parameters of the thin edge of the plastic part in each target sub-area are transmitted to S2; S2: Using a built-in recorder of the injection molding machine, the process parameters of the thin-edge injection molding process of the plastic parts in each target sub-region are recorded respectively, and then the process parameters of the thin-edge injection molding process of the plastic parts in each target sub-region are pre-processed in parallel, and the pre-processed process parameters of the thin-edge injection molding process of the plastic parts in each target sub-region are transmitted to S3; S3: By extracting data features of the process parameters of the thin edge injection molding process of the plastic part in each target sub-region, the temperature fluctuation value, melt pressure loss and acceleration pressure loss in each target sub-region are obtained respectively, and the extracted temperature fluctuation value, melt pressure loss and acceleration pressure loss in each target sub-region are transmitted to S4; S4: Parallel analysis is performed on the extracted temperature fluctuation values, melt pressure loss, and acceleration pressure loss in each target sub-region, and the injection pressure loss value of the sub-region is calculated, and the injection pressure loss value of the sub-region is transmitted to S5; S5: The injection pressure loss values ​​of the sub-regions analyzed in each target sub-region are comprehensively analyzed and a thin edge comprehensive pressure loss evaluation index is calculated. The thin edge comprehensive pressure loss evaluation index evaluates the overall loss of injection pressure at the thin edge of the plastic part, and the thin edge comprehensive pressure loss evaluation index is transmitted to S6; S6: Calculate the pressure calibration coefficient based on the thin edge comprehensive pressure loss evaluation index, calibrate the thin edge injection pressure loss through the pressure calibration coefficient, control the injection pressure to make the thin edge fill uniformly, and transmit the pressure control adjustment execution instruction to S7; S7: Execute the pressure control adjustment execution instruction, adjust the injection molding process parameters, and generate a pressure adjustment stop execution instruction.

2. The method for controlling thin edge pressure of an automobile interior injection molded part according to claim 1, characterized in that: The area division method of S1 is as follows: According to the distribution of wall thickness variation of the thin edge of the plastic part, it is divided into different gradient areas from thin to thick, and the wall thickness of each area is numbered in sequence from thin to thick; The data collection method of S1 is: According to the number of areas divided by the thin-edge wall thickness distribution of the plastic part, a corresponding number of types of sensors are arranged on the injection molding machine to cover each target sub-area, and the process parameters of the thin-edge injection molding process of the plastic part in each target sub-area are measured and collected, including temperature, pressure, holding time and speed. The types of sensors include pressure sensors, temperature sensors and speed sensors.

3. The method for controlling thin edge pressure of an automobile interior injection molded part according to claim 1, characterized in that: The S2 automatically records the process parameters of the thin-edge injection molding process of plastic parts in each target sub-area in chronological order by setting the data recording time of each area in the built-in recorder, and then stores them in the database according to the divided areas. The specific operation of the parallel preprocessing of the process parameters of the thin-edge injection molding process of plastic parts in each target sub-area is: data cleaning, filtering and removal of abnormal values ​​of the process parameters of the thin-edge injection molding process of plastic parts in multiple target sub-areas at the same time.

4. The method for controlling thin edge pressure of an automobile interior injection molded part according to claim 1, characterized in that: S3 extracts the characteristics of the pre-processed thin edge injection molding process parameters of each target sub-region, obtains the characteristic parameters that affect the injection molding pressure change of the thin edge of the plastic part, and calculates them; The temperature fluctuation value is obtained by periodically recording the actual value of the mold temperature T from the beginning of injection molding. a1 , T a2 ,Λ,T an , actual value of melt temperature T b1 , T b2 ,Λ,T bn And the actual value of the ambient temperature T c1 , T c2 ,Λ,T cn , the calculation formula for temperature fluctuation value is T ai Indicates recording the actual value of the mold temperature for the i-th time, T bi Indicates recording the actual value of the melt temperature for the i-th time, T ci Indicates recording the actual value of the i-th ambient temperature, Indicates the average value of the mold temperature recorded n times, Indicates the average value of the melt temperature recorded n times, T c Indicates the average value of the ambient temperature recorded n times; The melt pressure loss is used to monitor the pressure loss during melt friction during the injection molding process and record the actual value of the melt temperature T for the i-th time. bi , the calculation formula for melt pressure loss is L represents the length of the melt flow channel, represents the average flow rate of the melt during injection molding, D represents the flow channel diameter, u0 represents the viscosity of the melt at the reference temperature T0, t0 represents the reference temperature of the melt, α represents the temperature index, and 0.3≤α≤0.

6. The specific value is adjusted according to experimental data; The acceleration pressure loss is used to monitor the pressure loss caused by the acceleration and deceleration of the melt in the flow channel during the injection molding process. The melt inlet velocity v1 and outlet velocity v2 are recorded respectively. The calculation formula for the acceleration pressure loss is: ρ represents the density of the melt.

5. The method for controlling thin edge pressure of automobile interior injection molded parts according to claim 1, characterized in that: The S4 simultaneously analyzes the sub-region injection pressure loss values ​​in multiple target sub-regions through the temperature fluctuation value ΔT, melt pressure loss ΔP1 and acceleration pressure loss ΔP2 in each target sub-region. The calculation formula of the sub-region injection pressure loss value is Δp j =(ΔP1+ΔP2+P′) ΔT , P′ represents the local pressure loss, and the sub-region injection pressure loss value calculated for each target sub-region is transmitted to S5.

6. The method for controlling thin edge pressure of an automobile interior injection molded part according to claim 1, characterized in that: The S5 monitors and evaluates the overall injection pressure loss state through the thin edge comprehensive pressure loss evaluation index. The formula for calculating the thin edge comprehensive pressure loss evaluation index is: Δp1, Δp2, Δp3, Λ, Δp m Indicates the injection pressure loss value of the 1st, 2nd, 3rd...mth target sub-region, Δp j represents the injection pressure loss value of the jth sub-region, It represents the average value of the injection pressure loss values ​​of m sub-areas.

7. The method for controlling thin edge pressure of an automobile interior injection molded part according to claim 1, characterized in that: The S6 calculates the pressure calibration coefficient by comparing the thin edge comprehensive pressure loss evaluation index with the preset pressure loss threshold. S represents the thin edge comprehensive pressure loss evaluation index, s′ represents the preset pressure loss threshold. When the pressure calibration coefficient u is in the range of (0,1), it means that the pressure loss in the current injection molding process is within the controllable range, the quality of the injection molded parts meets the design requirements, and there is no need to control and adjust the pressure. When the pressure calibration coefficient u is in the range of [1, +∞), it means that the pressure loss in the injection molding process exceeds the controllable range. At this time, the pressure loss will have an adverse effect on the quality of the injection molded parts. The injection molding process needs to be controlled and adjusted, and the pressure control adjustment execution instruction is immediately generated and transmitted to S7.

8. The method for controlling thin edge pressure of an automobile interior injection molded part according to claim 1, characterized in that: The S7 is used to receive and execute the pressure control adjustment execution instruction, adjust the injection molding process parameters, and monitor the pressure changes during the adjustment process in real time. When the pressure loss is detected to be within the controllable range, the pressure adjustment stop execution instruction is immediately triggered, and the pressure adjustment stop execution instruction is sent to S6, and the execution behavior is stopped.

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