Method for monitoring and optimizing buckling deformation of automobile injection-molded part in injection molding process

Abstract

The invention relates to the technical field of material processing, in particular to an automobile injection molded part buckling deformation monitoring optimization method in the injection molding process, which comprises the following steps: S1, material characteristic detection; s2, detecting the quality of the injection molded part; s3, analyzing the quality of the injection molded part; s4, injection molding process detection; s5, analyzing an injection molding process; s6, cooling analysis, according to the overlapping length of the edge contour of each injection molding part sample and the standard contour, the shrinkage rate of each injection molding part sample is obtained, then the optimal material is selected, the injection molding process demand adjustment coefficient is analyzed, the pouring gate position is regulated and controlled accordingly, reinspection is conducted, and the process demand adjustment coefficient of the automobile injection molding part is analyzed; according to the method, the injection molding part is adjusted and rechecked, whether the injection molding part is cooled unevenly or not is judged by analyzing the temperature change overlapping degree of the area of the injection molding part, adjustment and recheck are conducted accordingly, the injection molding process can be optimized, the injection molding technology can better meet the actual requirement, and the effectiveness and accuracy of all adjustments are ensured.

Description

Technical Field

[0001] The invention relates to the technical field of material processing, in particular to a method for monitoring and optimizing warping deformation during the injection molding process of automobile injection molding parts. Background Art

[0002] In the modern automobile manufacturing industry, injection molded parts are widely used and vital. With the continuous development and progress of the automobile industry, the quality and performance requirements of automobile injection molded parts are also increasing. Over the years, automobile manufacturers have often faced quality problems caused by warping of injection molded parts during the production process. It may cause the injection molded parts to fail to meet the design requirements, which not only increases production costs and time, affects the overall assembly and performance of the car, but also may affect the market competitiveness of the product. Faced with fierce market competition and consumers' demand for high-quality automobiles, companies urgently need a method that can monitor and effectively optimize the warping deformation in the injection molding process in real time.

[0003] For example, the existing Chinese patent with application number 202010057636.5 discloses a method for improving the warping deformation of automobile headlight cover. This scheme determines the appropriate mold structure and injection molding process parameters by optimizing the mold structure, trial molding and solving the product appearance defects, thereby ensuring the quality and performance of the product. By confirming the stability of the injection molding process and a series of comparative analyses, the product quality is strictly controlled. Through mold flow analysis deviation correction and related operations, the warping deformation can be accurately evaluated and corrected, which greatly improves the warping deformation problem of the product.

[0004] However, the above patent has the following problems: First, the solution mainly focuses on the control of injection molding process parameters such as injection pressure, injection temperature, holding time, cooling time, etc., but ignores the selection of injection molding materials. The performance of different batches of materials may vary, which will affect the injection molding process and product quality.

[0005] Second, the solution does not explicitly mention the factor of cooling temperature uniformity during cooling. The uniformity of cooling temperature may also have an important impact on the quality and warping of the product. Uneven cooling will affect the inconsistent shrinkage of the product, making it difficult to ensure dimensional accuracy. Cooling some areas too fast or too slow may also cause quality problems such as shrinkage marks, bubbles, and deformation in the product, reducing overall production efficiency. Summary of the invention

[0006] In order to overcome the shortcomings of the background technology, an embodiment of the present invention provides a method for monitoring and optimizing the warpage deformation during the injection molding process of automobile injection molded parts, which can effectively solve the problems involved in the above-mentioned background technology.

[0007] The purpose of the present invention can be achieved through the following technical solutions: A method for monitoring and optimizing the warpage deformation of automobile injection molding process, the method comprising the following steps: S1. Material property detection: The shrinkage rate of each injection molding sample is obtained by the overlapping length of the edge contour of each injection molding sample with the standard contour, and then the best material is selected.

[0008] S2. Injection molded parts quality inspection: The quality parameters of automotive injection molded parts are inspected, including filling adequacy and weld mark length.

[0009] S3. Injection molded parts quality analysis: Based on the quality parameter analysis of automobile injection molded parts, the injection molding process demand adjustment coefficient of automobile injection molded parts is obtained, and the gate position is adjusted and re-inspected based on this.

[0010] S4. Injection molding process testing: Test the injection molding process parameters of automotive injection molding parts. The injection molding process parameters include the injection pressure, injection speed, and holding time of the injection molding machine.

[0011] S5. Injection molding process analysis: according to the injection molding process parameter analysis of automobile injection molding parts, the process demand adjustment coefficient of automobile injection molding parts is obtained, and the process demand adjustment coefficient of automobile injection molding parts is adjusted and re-checked.

[0012] S6. Cooling analysis: Detect the temperature of each area of ​​the injection molded part at each temperature time point to form a temperature change curve of each area of ​​the injection molded part, and then analyze the degree of overlap of the temperature change of the injection molded part area to determine whether there is uneven cooling of the injection molded part, so as to adjust and control it and re-check the degree of overlap of the temperature change of the injection molded part area after adjustment.

[0013] Preferably, the specific analysis method for material property detection is as follows: in the first step, the design drawings of the mold cavity of the automobile injection molded part are extracted from the management database, and the standard contour of the automobile injection molded part is obtained by edge detection technology.

[0014] In the second step, each injection molding material of the automobile injection molding part is poured into the mold cavity for injection molding, and the injection molding parts after injection molding are recorded as each injection molding sample, and the image of each injection molding sample is obtained, and the edge contour of each injection molding sample is extracted therefrom, which is recorded as each injection molding sample edge contour.

[0015] In the third step, the edge contour of each injection molded part sample is superimposed with the standard contour of the automobile injection molded part to obtain the overlapping length of the edge contour of each injection molded part sample and the standard contour.

[0016] The fourth step is to measure the standard contour length of the automobile injection molded parts, and obtain the deviation length of the edge contour of each injection molded part sample by subtracting the standard contour length of the automobile injection molded parts from the overlapping length of the edge contour of each injection molded part sample with the standard contour.

[0017] The fifth step is to obtain the shrinkage rate of each injection molded part sample based on the edge profile deviation length analysis of each injection molded part sample, so as to further select the best injection molding material.

[0018] Preferably, the specific analysis method for the injection molded part quality inspection is as follows: the first step is to read the injection molded part sample corresponding to the best injection molding material, which is recorded as the automobile injection molded part sample, irradiate and scan the automobile injection molded part sample with X-rays to generate an X-ray image of the automobile injection molded part sample, grayscale the X-ray image of the automobile injection molded part sample, and detect the grayscale value of each pixel point in the grayscale X-ray image of the automobile injection molded part sample, compare the measured grayscale value with a preset grayscale value threshold, screen out the pixel points in the X-ray image of the automobile injection molded part sample whose grayscale value is lower than the preset grayscale value threshold, record them as low grayscale pixel points, count the number of low grayscale pixel points, record them as g, and read the grayscale value of each low grayscale pixel point, record them as σ j , j represents the number of the jth low grayscale pixel, j = 1, 2, ..., g, and substitute it into the formula The filling adequacy degree β of the automobile injection molded parts is obtained, σ0 represents the preset gray value threshold, g 总 represents the total number of pixels in the X-ray image of the automobile injection molded part sample, φ1 and φ2 represent the grayscale value of the set low grayscale pixels and the weight factor of the number of low grayscale pixels, respectively, and g represents the number of low grayscale pixels.

[0019] The second step is to read the automobile injection molded parts sample and obtain its image through a high-definition camera, which is recorded as the automobile injection molded parts sample image. The edge contour of each weld mark in the automobile injection molded parts sample image is extracted through edge detection technology, and its length is measured, which is recorded as the length of each weld mark of the automobile injection molded parts sample. The length of the weld mark of the automobile injection molded parts is obtained by accumulating it, which is recorded as D.

[0020] Preferably, the specific analysis method of the injection molded part quality analysis is as follows: the first step is to read the filling adequacy β and the weld line length D of the automobile injection molded part, and substitute them into the formula The injection molding process demand adjustment coefficient δ of automobile injection molding parts is obtained, D0 represents the preset maximum allowable length of the weld mark, φ3 and φ4 represent the weight factors of the set filling adequacy and weld mark length, respectively.

[0021] In the second step, the injection molding process demand adjustment coefficient of the automobile injection molding parts is compared with the preset injection molding process demand adjustment coefficient threshold. If the injection molding process demand adjustment coefficient of the automobile injection molding parts is greater than or equal to the preset injection molding process demand adjustment coefficient threshold, it means that the gate position is not appropriate and the gate position needs to be redesigned, and the injection molding process demand adjustment coefficient of the automobile injection molding parts is rechecked. Otherwise, it means that the gate position is appropriate and no adjustment is required.

[0022] Preferably, the specific analysis method of the injection molding process detection is as follows: the first step is to select the key parts of the injection molding machine according to the settings, and at the same time, select a number of time points with equal time intervals within the total injection molding time according to a fixed time length, which are recorded as the time points of the key parts of the injection molding machine, and the pressure of the key parts of the injection molding machine at each time point is detected by a pressure sensor, which is recorded as P fk , f represents the number of the fth key part, f = 1, 2, ..., h, k represents the number of the kth time point, k = 1, 2, ..., l, and substitute it into the formula Get the pressure P of each key part of the injection molding machine f , l represents the number of time points.

[0023] The second step is to install a weight sensor at the outlet of the injection molding machine to monitor the weight of the injection molding material output at each time point of the injection molding machine, which is recorded as M k , let the fixed time be Δt, and use the formula Get the injection speed V of the injection molding machine.

[0024] The third step is that after the injection molding material is filled, it enters the pressure holding stage and monitors the pressure holding time of the injection molded part, which is recorded as T.

[0025] Preferably, the specific analysis method of the injection molding process analysis is: the first step is to read the pressure P of each key part of the injection molding machine respectively. f , injection molding machine injection speed V, injection molding part holding time T, substitute it into the formula The process demand adjustment coefficient χ of automobile injection molding parts is obtained, where P0, V0, and T0 represent the reference values ​​of preset pressure, injection speed, and holding time, respectively. The weight factors of the set pressure, injection speed and holding time are respectively represented. The process requirement adjustment coefficient of the automobile injection molding part is compared with the preset process requirement adjustment coefficient threshold. If the process requirement adjustment coefficient of the automobile injection molding part is greater than or equal to the preset process requirement adjustment coefficient threshold, it means that the process parameters of the automobile injection molding part need to be adjusted, otherwise it means that the process parameters of the automobile injection molding part do not need to be adjusted.

[0026] Preferably, the specific analysis method for adjusting the process parameters of automobile injection molding parts is as follows: the first step is to read the pressure of each key part of the injection molding machine, and obtain the pressure demand adjustment value by subtracting it from the preset pressure reference value. If the pressure demand adjustment value is a positive number, the injection molding machine pressure is increased according to the pressure demand adjustment value; if the pressure demand adjustment value is a negative number, the injection molding machine pressure is decreased according to the pressure demand adjustment value, and the adjusted injection molding machine pressure is recorded as the injection molding machine adjustment pressure.

[0027] The second step is to read the injection speed of the injection molding machine, and obtain the injection speed demand adjustment value by subtracting it from the preset injection speed reference value. The weight of the injection molding material output per unit time point of the injection molding machine is controlled according to the injection speed demand adjustment value. The injection speed of the injection molding machine and the injection speed demand adjustment value are summed to obtain the injection speed of the injection molding machine.

[0028] The third step is to read the holding time of the injection molded part, and obtain the holding time requirement adjustment value by subtracting it from the preset holding time reference value. If the holding time requirement adjustment value is a positive number, the holding time of the injection molded part is increased according to the holding time requirement adjustment value. If the holding time requirement adjustment value is a negative number, the holding time of the injection molded part is reduced according to the holding time requirement adjustment value, and the adjusted holding time is recorded as the injection molding machine adjusted holding time.

[0029] Preferably, the specific analysis method for re-checking the process requirement adjustment coefficient of automobile injection molded parts is: respectively read the injection molding machine adjustment pressure, the injection molding machine adjustment injection speed, and the injection molding machine adjustment holding time, and analyze according to the method of analyzing the process requirement adjustment coefficient of automobile injection molded parts to obtain the process requirement adjustment coefficient of automobile injection molded parts after process parameter adjustment, and compare it with the preset process requirement adjustment coefficient threshold again. If the process requirement adjustment coefficient of automobile injection molded parts after process parameter adjustment is less than the preset process requirement adjustment coefficient threshold, it means that the process parameter adjustment is qualified, otherwise it means that the process parameter adjustment is unqualified, and the process parameters of automobile injection molded parts are adjusted again until the process parameters are qualified.

[0030] Preferably, the specific analysis method of the cooling analysis is as follows: in the first step, a number of time points are selected during the cooling time of the injection molded part according to a set time interval, recorded as each temperature time point, the injection molded part is divided into a number of regions according to a set area, and a number of equally spaced detection points are randomly selected in each region of the injection molded part, recorded as each temperature detection point, and the temperature of each temperature time point in each region of the injection molded part is obtained, and the temperature of each temperature time point in each region of the injection molded part is obtained by taking the average value, which is recorded as x represents the number of the x-th temperature time point, x=1, 2, ..., y, and a represents the number of the a-th area, a=1, 2, ..., b.

[0031] In the second step, a two-dimensional coordinate system is constructed with the temperature time point as the horizontal coordinate and the temperature as the vertical coordinate, and then several points are marked in the constructed two-dimensional coordinate system for the temperature of each temperature time point in each area of ​​the injection molded part to form a temperature change curve of each area of ​​the injection molded part. The temperature change curves of each area of ​​the injection molded part are overlapped to obtain the overlapping degree of temperature change in the injection molded part area, and the overlapping degree is compared with the preset overlapping degree threshold. If the overlapping degree of temperature change in the injection molded part area is greater than or equal to the preset overlapping degree threshold, it means that there is no uneven cooling of the injection molded part. Otherwise, it means that there is uneven cooling of the injection molded part. It is regulated and the overlapping degree of temperature change in the injection molded part area after regulation is re-inspected.

[0032] Preferably, the specific analysis method for re-inspecting the degree of overlap of the temperature changes in the injection molded parts after regulation is as follows: an adjustable flow control valve is installed in the pipeline of the cooling medium, the flow rate is adjusted according to demand, and the temperature of each temperature time point in each area of ​​the injection molded parts after regulation is obtained according to the previously set time interval, area division and detection point selection method, and the degree of overlap of the temperature changes in the injection molded parts areas after regulation is analyzed according to the degree of overlap of the temperature changes in the injection molded parts areas, and the overlap is obtained, and it is compared with the preset overlap threshold again. If the overlap of the temperature changes in the injection molded parts areas after regulation is greater than or equal to the preset overlap threshold, it indicates that there is no uneven cooling of the injection molded parts after regulation, otherwise it indicates that there is still uneven cooling of the injection molded parts after regulation, and it is regulated again until the overlap of the temperature changes in the injection molded parts areas is greater than or equal to the preset overlap threshold.

[0033] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects: 1. The present invention obtains the shrinkage rate of each injection molded part sample by the overlapping length of the edge contour of each injection molded part sample with the standard contour, and then selects the best material, which helps to select the most suitable material and improve product performance and quality.

[0034] 2. The present invention obtains the injection molding process demand adjustment coefficient based on the quality parameter analysis of the injection molded part, and uses it to adjust and re-check the gate position, which can optimize the injection molding process and improve the molding effect of the injection molded part.

[0035] 3. The present invention obtains the process requirement adjustment coefficient of the automobile injection molded parts according to the injection molding process parameter analysis of the automobile injection molded parts, adjusts it and re-checks the process requirement adjustment coefficient of the automobile injection molded parts, which can make the injection molding process more in line with actual needs and further improve product quality.

[0036] 4. The present invention obtains the degree of overlap of temperature changes in the injection molded part area according to the temperature of each area of ​​the injection molded part at each temperature time point, and then determines whether the injection molded part has uneven cooling. The regulation is carried out accordingly and the degree of overlap of temperature changes in the injection molded part area after regulation is re-inspected, which can effectively avoid the problem of uneven cooling and reduce the occurrence of defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention is further described using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention. A person skilled in the art can obtain other drawings based on the following drawings without creative work.

[0038] Figure 1 It is a schematic diagram of the method flow of the present invention.

[0039] Figure 2 for Figure 1 Schematic diagram of the method flow chart of step S1 in FIG.

[0040] Figure 3 for Figure 1 Schematic diagram of the process flow of the method for adjusting the process parameters of automobile injection molding parts in step S5. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] See also Figure 1 As shown, the present invention provides a method for monitoring and optimizing warpage deformation during the injection molding process of automobile injection molded parts, the method comprising the following steps: S1. Material property detection: the shrinkage rate of each injection molded part sample is obtained by the overlapping length of the edge contour of each injection molded part sample with the standard contour, and then the best material is selected.

[0043] See also Figure 2 As shown, the specific analysis method of the material property detection is as follows: the first step is to extract the design drawings of the mold cavity of the automobile injection molding part from the management database, and obtain the standard contour of the automobile injection molding part through edge detection technology.

[0044] In the second step, each injection molding material of the automobile injection molding part is poured into the mold cavity for injection molding, and the injection molding parts after injection molding are recorded as each injection molding sample, and the image of each injection molding sample is obtained, and the edge contour of each injection molding sample is extracted therefrom, which is recorded as each injection molding sample edge contour.

[0045] In the third step, the edge contour of each injection molded part sample is superimposed with the standard contour of the automobile injection molded part to obtain the overlapping length of the edge contour of each injection molded part sample and the standard contour.

[0046] The fourth step is to measure the standard contour length of the automobile injection molded parts, and obtain the deviation length of the edge contour of each injection molded part sample by subtracting the standard contour length of the automobile injection molded parts from the overlapping length of the edge contour of each injection molded part sample with the standard contour.

[0047] The fifth step is to obtain the shrinkage rate of each injection molded part sample based on the edge contour deviation length analysis of each injection molded part sample, so as to further select the best injection molding material; the most suitable injection molding material can be accurately screened to ensure that the injection molded parts are optimal in terms of dimensional accuracy and quality.

[0048] It should be noted that the specific analysis method of the optimal injection molding material is: read the edge profile deviation length of each injection molded sample, recorded as Δd m , m represents the number of the injection molded part of the mth injection molded part sample, m = 1, 2, ..., q, and the standard contour length of the automobile injection molded part is recorded as d 总 , substituting it into the formula, we get Get the shrinkage rate α of each injection molded sample m , arrange the shrinkage rates of each injection molded part sample in ascending order, and record the material of the injection molded part sample corresponding to the first shrinkage rate as the best injection molding material; sorting by shrinkage rate can intuitively find the best material and ensure that the injection molded parts perform best in terms of dimensional stability and other aspects.

[0049] S2. Injection molded parts quality inspection: The quality parameters of automotive injection molded parts are inspected, including filling adequacy and weld mark length.

[0050] The specific analysis method for the injection molded part quality inspection is as follows: the first step is to read the injection molded part sample corresponding to the best injection molding material, which is recorded as the automobile injection molded part sample, irradiate and scan the automobile injection molded part sample with X-rays to generate an X-ray image of the automobile injection molded part sample, grayscale the X-ray image of the automobile injection molded part sample, and detect the grayscale value of each pixel point in the grayscale X-ray image of the automobile injection molded part sample, compare the measured grayscale value with a preset grayscale value threshold, screen out the pixel points in the X-ray image of the automobile injection molded part sample whose grayscale value is lower than the preset grayscale value threshold, record them as low grayscale pixel points, count the number of low grayscale pixel points, record them as g, and read the grayscale value of each low grayscale pixel point, record them as σ j , j represents the number of the jth low grayscale pixel, j = 1, 2, ..., g, substitute it into the formula The filling adequacy degree β of the automobile injection molded parts is obtained, σ0 represents the preset gray value threshold, g 总represents the total number of pixels in the X-ray image of the automobile injection molded parts sample, φ1 and φ2 represent the grayscale value of the set low grayscale pixels and the weight factor of the number of low grayscale pixels, respectively, and g represents the number of low grayscale pixels. Through X-ray irradiation scanning and subsequent processing, the internal structure and filling condition of the injection molded parts can be non-destructively detected, the filling adequacy of the automobile injection molded parts can be clarified, and it is helpful to timely discover possible filling defects.

[0051] It should be noted that, in a specific embodiment, φ1 can be set to 0.5, φ2 can be set to 0.5, the grayscale value of low-grayscale pixels can reflect the difference in grayscale value from the normal filling area, and has a strong indicative effect on the degree of filling adequacy. The grayscale value of low-grayscale pixels may reflect the filling situation of certain local areas. If the grayscale value of low-grayscale pixels is too low and the number is large, it may indicate a high possibility of insufficient filling or defects, so the corresponding weights are equal.

[0052] The second step is to read the automobile injection molded parts sample and obtain its image through a high-definition camera, which is recorded as the automobile injection molded parts sample image. The edge contour of each weld mark in the automobile injection molded parts sample image is extracted through edge detection technology, and its length is measured, which is recorded as the length of each weld mark of the automobile injection molded parts sample. The weld mark length of the automobile injection molded parts is obtained by accumulating them, which is recorded as D. Problems with weld marks can be discovered in time so that targeted measures can be taken to improve them, thereby ensuring that the automobile injection molded parts meet the requirements in appearance and performance and improving the overall quality of the product.

[0053] S3. Injection molded parts quality analysis: Based on the quality parameter analysis of automobile injection molded parts, the injection molding process demand adjustment coefficient of automobile injection molded parts is obtained, and the gate position is adjusted and re-inspected based on this.

[0054] The specific analysis method of the injection molded part quality analysis is as follows: the first step is to read the filling adequacy β and weld line length D of the automobile injection molded part and substitute them into the formula The injection molding process demand adjustment coefficient δ of automobile injection molding parts is obtained, D0 represents the preset maximum allowable length of the weld mark, φ3 and φ4 represent the weight factors of the set filling adequacy and weld mark length, respectively; the influence of the two important factors of filling adequacy and weld mark length on the quality of injection molding parts can be fully considered, which is helpful to accurately control the injection molding process parameters and improve the accuracy and efficiency of production.

[0055] It should be noted that, in a specific embodiment, φ3 can be set to 0.5, and φ4 can be set to 0.5. The degree of filling adequacy mainly affects the strength and appearance quality of the injection molded parts. If the filling is insufficient, it may cause defects in the injection molded parts, such as shrinkage holes, bubbles, etc., thereby affecting their strength and reliability. In addition, insufficient filling may also affect the appearance quality of the injection molded parts, causing depressions or unevenness on the surface. The length of the weld mark mainly affects the appearance quality of the injection molded parts. The weld mark refers to the mark formed during the injection molding process due to the convergence of the plastic melt when it flows in the mold. If the weld mark is too long, it may affect the appearance quality of the injection molded parts and cause obvious marks to appear on the surface. Therefore, the corresponding weights are equal.

[0056] In the second step, the injection molding process demand adjustment coefficient of the automobile injection molding parts is compared with the preset injection molding process demand adjustment coefficient threshold. If the injection molding process demand adjustment coefficient of the automobile injection molding parts is greater than or equal to the preset injection molding process demand adjustment coefficient threshold, it means that the gate position is inappropriate and the gate position needs to be redesigned, and the injection molding process demand adjustment coefficient of the automobile injection molding parts is rechecked. Otherwise, it means that the gate position is appropriate and no adjustment is required. This is convenient for timely discovery of inappropriate gate positions so that measures can be taken to improve them and avoid producing a large number of unqualified products.

[0057] It should be noted that the specific analysis method for re-checking the injection molding process demand adjustment coefficient of automobile injection molded parts is: after redesigning the gate position, the filling adequacy and weld mark length of the automobile injection molded parts are detected again, and the injection molding process demand adjustment coefficient of the automobile injection molded parts after the gate position is adjusted is obtained according to the method of analyzing the injection molding process demand adjustment coefficient of the automobile injection molded parts, and the injection molding process demand adjustment coefficient is compared with the preset injection molding process demand adjustment coefficient threshold again. If the injection molding process demand adjustment coefficient of the automobile injection molded parts after the gate position is adjusted is less than the preset injection molding process demand adjustment coefficient threshold, it means that the gate position adjustment is appropriate, otherwise it means that the gate position adjustment is inappropriate, and the fourth step is executed again until the injection molding process demand adjustment coefficient of the automobile injection molded parts after the gate position is adjusted is less than the preset injection molding process demand adjustment coefficient threshold.

[0058] S4. Injection molding process testing: Test the injection molding process parameters of automotive injection molding parts. The injection molding process parameters include the injection pressure, injection speed, and holding time of the injection molding machine.

[0059] The specific analysis method of the injection molding process detection is as follows: the first step is to select the key parts of the injection molding machine according to the settings, and at the same time, select a number of time points with equal time intervals within the total injection molding time according to a fixed time, which are recorded as the time points of the key parts of the injection molding machine, and detect the pressure of the key parts of the injection molding machine at each time point through a pressure sensor, which is recorded as P fk, f represents the number of the fth key part, f = 1, 2, ..., h, k represents the number of the kth time point, k = 1, 2, ..., l, and substitute it into the formula Get the pressure P of each key part of the injection molding machine f , l represents the number of time points; it can fully understand the pressure changes of key parts of the injection molding machine during the entire injection molding process, which helps to accurately grasp the operating status of the equipment and promptly discover abnormal pressure conditions so as to take targeted measures to prevent equipment failures and production accidents.

[0060] The second step is to install a weight sensor at the discharge port of the injection molding machine to monitor the weight of the injection molding material output within the set time of the injection molding machine, which is recorded as M. The set time is recorded as Δt. The formula Get the injection speed V of the injection molding machine; be able to grasp the injection speed of the injection molding machine in real time, so as to adjust and optimize the process parameters in time, ensure the injection molding quality, help discover abnormal injection speed, and warn of possible problems in advance.

[0061] The third step is that after the injection molding material is filled, the pressure holding stage begins, and the pressure holding time of the injection molded part is monitored, which is recorded as T. Ensuring accurate time control during the pressure holding stage helps optimize product quality, such as reducing defects such as shrinkage marks, and facilitates analysis and adjustment of the impact of the pressure holding time on the final performance of the product, thereby achieving better process optimization.

[0062] S5. Injection molding process analysis: according to the injection molding process parameter analysis of automobile injection molding parts, the process demand adjustment coefficient of automobile injection molding parts is obtained, and the process demand adjustment coefficient of automobile injection molding parts is adjusted and re-checked.

[0063] The specific analysis method of the injection molding process analysis is: read the pressure P of each key part of the injection molding machine respectively f , injection molding machine injection speed V, injection molding part holding time T, substitute it into the formula The process demand adjustment coefficient χ of automobile injection molding parts is obtained, where P0, V0, and T0 represent the reference values ​​of preset pressure, injection speed, and holding time, respectively. The weight factors respectively represent the set pressure, injection speed and holding time, and the process demand adjustment coefficient of the automobile injection molding parts is compared with the preset process demand adjustment coefficient threshold. If the process demand adjustment coefficient of the automobile injection molding parts is greater than or equal to the preset process demand adjustment coefficient threshold, it means that the process parameters of the automobile injection molding parts need to be adjusted, otherwise it means that the process parameters of the automobile injection molding parts do not need to be adjusted; the quantitative evaluation and precise control of the injection molding process are realized, the scientificity and rationality of the process are improved, which is helpful to optimize the production process and improve the production efficiency and the stability of product quality.

[0064] It should be noted that, in a specific embodiment, It can be set to 0.5. It can be set to 0.2. It can be set to 0.3. Pressure has a vital influence on the filling effect, density, dimensional accuracy, etc. of injection molded parts. Appropriate pressure can ensure that the plastic melt fully fills the cavity to avoid defects such as short shots and bubbles. It has a very direct and critical impact on product quality. The holding time is second, because it mainly affects the shrinkage compensation of the product during the cooling process, can reduce shrinkage and warping deformation, and has a greater impact on the dimensional stability and appearance of the final product. However, compared with pressure, its comprehensiveness is slightly weaker. The weight of injection speed is relatively small. Although it will affect the flow and filling mode of the melt, by reasonably adjusting parameters such as pressure and holding pressure, it can sometimes compensate for the impact of improper injection speed to a certain extent. Moreover, its impact on product quality is not as critical and direct as pressure and holding time. Therefore, the weight corresponding to pressure is the highest, followed by holding time, and the weight corresponding to injection speed is lower.

[0065] See also Figure 3 As shown, the specific analysis method for adjusting the process parameters of automobile injection molding parts is as follows: the first step is to read the pressure of each key part of the injection molding machine, and obtain the pressure demand adjustment value by subtracting it from the preset pressure reference value. If the pressure demand adjustment value is a positive number, the pressure of the injection molding machine is increased according to the pressure demand adjustment value. If the pressure demand adjustment value is a negative number, the pressure of the injection molding machine is decreased according to the pressure demand adjustment value, and the adjusted pressure of the injection molding machine is recorded as the injection molding machine adjustment pressure; it can ensure that the pressure of each key part of the injection molding machine is within a suitable range, which is conducive to improving product quality, quickly responding to changes in pressure and making adjustments in time, and maintaining production stability.

[0066] The second step is to read the injection speed of the injection molding machine, and obtain the injection speed demand adjustment value by subtracting it from the preset injection speed reference value. The weight of the injection molding material output per unit time point of the injection molding machine is controlled according to the injection speed demand adjustment value. The injection speed of the injection molding machine and the injection speed demand adjustment value are summed to obtain the injection speed of the injection molding machine. This can ensure that the injection speed of the injection molding machine meets specific requirements, ensure the consistency of product quality, achieve effective control of the output of injection molding materials, and avoid material waste.

[0067] It should be noted that the specific analysis method of the injection molding material weight output per unit time point of the injection molding machine is as follows: read the injection speed demand adjustment value, recorded as ΔV, and use the formula ΔM = Δt*ΔV*M 螺杆 *ρ m Get the injection material weight ΔM output per unit time point of the injection molding machine, M 螺杆 Indicates the set cross-sectional area of ​​the injection molding machine screw, ρ m It represents the density of the injection material of the mth injection molded part sample.

[0068] The third step is to read the holding time of the injection molded part, and obtain the holding time requirement adjustment value by subtracting it from the preset holding time reference value. If the holding time requirement adjustment value is a positive number, the holding time of the injection molded part is increased according to the holding time requirement adjustment value. If the holding time requirement adjustment value is a negative number, the holding time of the injection molded part is reduced according to the holding time requirement adjustment value, and the adjusted holding time is recorded as the injection molding machine adjusted holding time; this can help effectively control the holding time and avoid quality problems or energy waste caused by being too long or too short.

[0069] The specific analysis method for re-checking the process requirement adjustment coefficient of automobile injection molded parts is: respectively read the injection molding machine adjustment pressure, the injection molding machine adjustment injection speed, and the injection molding machine adjustment holding time, and analyze the process requirement adjustment coefficient of automobile injection molded parts according to the method of analyzing the process requirement adjustment coefficient of automobile injection molded parts to obtain the process requirement adjustment coefficient of automobile injection molded parts after process parameter adjustment, and compare it with the preset process requirement adjustment coefficient threshold again. If the process requirement adjustment coefficient of automobile injection molded parts after process parameter adjustment is less than the preset process requirement adjustment coefficient threshold, it means that the process parameter adjustment is qualified, otherwise it means that the process parameter adjustment is unqualified, and the process parameters of automobile injection molded parts are adjusted again until the process parameters are qualified; ensure the rationality and accuracy of the process parameters in the production process of automobile injection molded parts, and achieve strict control and optimization adjustment of the process.

[0070] S6. Cooling analysis: Detect the temperature of each area of ​​the injection molded part at each temperature time point to form a temperature change curve of each area of ​​the injection molded part, and then analyze the degree of overlap of the temperature change of the injection molded part area to determine whether there is uneven cooling of the injection molded part, so as to adjust and control it and re-check the degree of overlap of the temperature change of the injection molded part area after adjustment.

[0071] The specific analysis method of the cooling analysis is as follows: in the first step, a number of time points are selected during the cooling time of the injection molded part according to a set time interval, recorded as each temperature time point, the injection molded part is divided into a number of regions according to a set area, and a number of equally spaced detection points are randomly selected in each region of the injection molded part, recorded as each temperature detection point, and the temperature of each temperature time point in each region of the injection molded part is obtained, and the temperature of each temperature time point in each region of the injection molded part is obtained by taking the average value, which is recorded as x represents the number of the x-th temperature time point, x=1, 2, ..., y, a represents the number of the a-th area, a=1, 2, ..., b; it helps to timely discover abnormal temperature areas or time points, so as to take targeted measures to optimize the cooling process.

[0072] The second step is to construct a two-dimensional coordinate system with the temperature time point as the horizontal axis and the temperature as the vertical axis, and then mark several points in the constructed two-dimensional coordinate system for the temperature of each temperature time point in each area of ​​the injection molded part to form a temperature change curve of each area of ​​the injection molded part. The overlap degree of the temperature change in the injection molded part area is analyzed and compared with the preset overlap degree threshold. If the overlap degree of the temperature change in the injection molded part area is greater than or equal to the preset overlap degree threshold, it means that there is no uneven cooling of the injection molded part. Otherwise, it means that there is uneven cooling of the injection molded part. It is regulated and the overlap degree of the temperature change in the injection molded part area after the regulation is re-inspected. By constructing a two-dimensional coordinate system and curve, the temperature change trend can be clearly and intuitively displayed, which is convenient for analysis and understanding. It can quickly determine whether there is an uneven cooling problem in the injection molded part and discover potential quality hazards in time.

[0073] It should be noted that the specific analysis method of the degree of overlap of the temperature changes in the injection molded parts is as follows: read the temperature change curves of each area of ​​the injection molded parts, take any two area temperature change curves as a group, record them as each group of temperature change curves, obtain the temperature corresponding to each temperature time point of each group of temperature change curves, and make a difference to obtain the temperature difference value of each temperature time point of each group of temperature change curves, which is recorded as i represents the number of the temperature change curve of the i-th group, i=1,2,...,n, through the formula Get the overlap degree of temperature change in the injection molded part area n represents the number of groups of temperature variation curves.

[0074] The specific analysis method for re-inspecting the degree of overlap of the temperature changes in the injection molded parts after regulation is as follows: an adjustable flow control valve is installed in the pipeline of the cooling medium, the flow rate is adjusted according to the demand, and the temperature of each temperature time point in each area of ​​the injection molded parts after regulation is obtained according to the previously set time interval, area division and detection point selection method, and the degree of overlap of the temperature changes in the injection molded parts after regulation is analyzed according to the degree of overlap of the temperature changes in the injection molded parts, and the overlap is obtained by comparing it with the preset overlap threshold again. If the degree of overlap of the temperature changes in the injection molded parts after regulation is greater than or equal to the preset overlap threshold, it means that there is no uneven cooling of the injection molded parts after regulation, otherwise it means that there is still uneven cooling of the injection molded parts after regulation, and it is regulated again until the degree of overlap of the temperature changes in the injection molded parts is greater than or equal to the preset overlap threshold; the adjustable flow control valve makes the cooling medium flow control more flexible, can better adapt to different situations, and continuously repeats the monitoring and regulation process to ensure that the ideal cooling uniformity state is finally achieved, thereby improving the stability of product quality.

[0075] The present invention obtains the shrinkage rate of each injection molded part sample by the overlapping length of the edge contour of each injection molded part sample with the standard contour, and then selects the best material, analyzes the injection molding process demand adjustment coefficient and uses it to regulate and re-inspect the gate position, analyzes the process demand adjustment coefficient of automobile injection molded parts, adjusts it and re-inspects it, analyzes the degree of overlap of the temperature change in the injection molded part area to determine whether the injection molded part has uneven cooling, and uses this to regulate and re-inspect, which can optimize the injection molding process, make the injection molding process more in line with actual needs, and ensure the effectiveness and accuracy of various adjustments. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present invention, which are still covered by the protection scope of the present invention.

Claims

1. A method for monitoring and optimizing the warpage deformation of automobile injection molding parts during injection molding process, characterized in that: The steps include: S1. Material property testing: The shrinkage rate of each injection molded sample is obtained by the overlapping length of the edge profile of each injection molded sample with the standard profile, and then the best material is selected; S2. Injection molded parts quality inspection: inspect the quality parameters of automotive injection molded parts, including filling adequacy and weld mark length; S3. Injection molded parts quality analysis: According to the quality parameter analysis of automobile injection molded parts, the injection molding process demand adjustment coefficient of automobile injection molded parts is obtained, and the gate position is adjusted and re-inspected based on this; S4. Injection molding process testing: Testing the injection molding process parameters of automotive injection molding parts, including the injection pressure, injection speed, and holding time of the injection molding machine; S5. Injection molding process analysis: according to the injection molding process parameters of automobile injection molding parts, the process demand adjustment coefficient of automobile injection molding parts is obtained, and the process demand adjustment coefficient of automobile injection molding parts is adjusted and re-inspected; S6. Cooling analysis: Detect the temperature of each area of ​​the injection molded part at each temperature time point to form a temperature change curve of each area of ​​the injection molded part, and then analyze the degree of overlap of the temperature change of the injection molded part area to determine whether there is uneven cooling of the injection molded part, so as to adjust and control it and re-check the degree of overlap of the temperature change of the injection molded part area after adjustment.

2. The method for monitoring and optimizing warpage deformation during the injection molding process of automobile injection molded parts according to claim 1, characterized in that: The specific analysis method for the material property detection is: The first step is to extract the design drawings of the mold cavity of the automobile injection molding parts from the management database and obtain the standard contour of the automobile injection molding parts through edge detection technology; In the second step, each injection molding material of the automobile injection molding part is poured into the mold cavity for injection molding, and the injection molding parts after injection molding are recorded as each injection molding part sample, and the image of each injection molding part sample is obtained, and the edge contour of each injection molding part sample is extracted therefrom, which is recorded as the edge contour of each injection molding part sample; The third step is to superimpose the edge contour of each injection molded part sample with the standard contour of the automobile injection molded part to obtain the overlapping length of the edge contour of each injection molded part sample with the standard contour; The fourth step is to measure the standard contour length of the automobile injection molded parts, and obtain the deviation length of the edge contour of each injection molded part sample by subtracting the standard contour length of the automobile injection molded parts and the overlapping length of the edge contour of each injection molded part sample with the standard contour; The fifth step is to obtain the shrinkage rate of each injection molded part sample based on the edge profile deviation length analysis of each injection molded part sample, so as to further select the best injection molding material.

3. The method for monitoring and optimizing warpage deformation during the injection molding process of automobile injection molded parts according to claim 2, characterized in that: The specific analysis method for the injection molded parts quality inspection is: In the first step, the injection molded part sample corresponding to the best injection molding material is read, which is recorded as the automobile injection molded part sample. The automobile injection molded part sample is irradiated and scanned by X-ray to generate an X-ray image of the automobile injection molded part sample. The X-ray image of the automobile injection molded part sample is grayed, and the gray value of each pixel point of the grayed automobile injection molded part sample X-ray image is detected. The measured gray value is compared with a preset gray value threshold, and the pixel points in the X-ray image of the automobile injection molded part sample whose gray value is lower than the preset gray value threshold are screened out, which are recorded as low gray pixel points, and the number of low gray pixel points is counted, which is recorded as g, and the gray value of each low gray pixel point is read, which is recorded as σ j , j represents the number of the jth low grayscale pixel, j = 1, 2, ..., g, and substitute it into the formula The filling adequacy degree β of the automobile injection molded parts is obtained, σ0 represents the preset gray value threshold, g 总 represents the total number of pixels in the X-ray image of the automobile injection molded part sample, φ1 and φ2 represent the gray value of the set low grayscale pixels and the weight factor of the number of low grayscale pixels, respectively, and g represents the number of low grayscale pixels; The second step is to read the automobile injection molded parts sample and obtain its image through a high-definition camera, which is recorded as the automobile injection molded parts sample image. The edge contour of each weld mark in the automobile injection molded parts sample image is extracted through edge detection technology, and its length is measured, which is recorded as the length of each weld mark of the automobile injection molded parts sample. The length of the weld mark of the automobile injection molded parts is obtained by accumulating it, which is recorded as D.

4. The method for monitoring and optimizing warpage deformation during the injection molding process of automobile injection molded parts according to claim 3, characterized in that: The specific analysis method of the injection molded parts quality analysis is: The first step is to read the filling adequacy β and weld line length D of the automotive injection molded parts and substitute them into the formula The injection molding process demand adjustment coefficient δ of automobile injection molding parts is obtained, D0 represents the preset maximum allowable length of the weld mark, φ3 and φ4 represent the weight factors of the set filling adequacy and weld mark length respectively; In the second step, the injection molding process demand adjustment coefficient of the automobile injection molding parts is compared with the preset injection molding process demand adjustment coefficient threshold. If the injection molding process demand adjustment coefficient of the automobile injection molding parts is greater than or equal to the preset injection molding process demand adjustment coefficient threshold, it means that the gate position is not appropriate and the gate position needs to be redesigned, and the injection molding process demand adjustment coefficient of the automobile injection molding parts is rechecked. Otherwise, it means that the gate position is appropriate and no adjustment is required.

5. The method for monitoring and optimizing warpage deformation during the injection molding process of automobile injection molded parts according to claim 1, characterized in that: The specific analysis method of the injection molding process detection is: In the first step, the key parts of the injection molding machine are selected according to the settings, and several time points with equal time intervals are selected within the total injection molding time according to the fixed time, which are recorded as the time points of the key parts of the injection molding machine. The pressure of each key part of the injection molding machine at each time point is detected by the pressure sensor, which is recorded as P fk , f represents the number of the fth key part, f = 1, 2, ..., h, k represents the number of the kth time point, k = 1, 2, ..., l, and substitute it into the formula Get the pressure P of each key part of the injection molding machine f , l represents the number of time points; The second step is to install a weight sensor at the discharge port of the injection molding machine to monitor the weight of the injection molding material output within the set time of the injection molding machine, which is recorded as M. The set time is recorded as Δt. The formula Get the injection speed V of the injection molding machine; The third step is that after the injection molding material is filled, it enters the pressure holding stage and monitors the pressure holding time of the injection molded part, which is recorded as T.

6. The method for monitoring and optimizing warpage deformation during the injection molding process of automobile injection molded parts according to claim 5, characterized in that: The specific analysis method of the injection molding process analysis is: Read the pressure P of each key part of the injection molding machine separately f , injection molding machine injection speed V, injection molding part holding time T, substitute it into the formula The process demand adjustment coefficient χ of automobile injection molding parts is obtained, where P0, V0, and T0 represent the reference values ​​of preset pressure, injection speed, and holding time, respectively. The weight factors of the set pressure, injection speed and holding time are respectively represented. The process requirement adjustment coefficient of the automobile injection molding part is compared with the preset process requirement adjustment coefficient threshold. If the process requirement adjustment coefficient of the automobile injection molding part is greater than or equal to the preset process requirement adjustment coefficient threshold, it means that the process parameters of the automobile injection molding part need to be adjusted, otherwise it means that the process parameters of the automobile injection molding part do not need to be adjusted.

7. The method for monitoring and optimizing warpage deformation during the injection molding process of automobile injection molded parts according to claim 6, characterized in that: The specific analysis method for adjusting the process parameters of automobile injection molding parts is: The first step is to read the pressure of each key part of the injection molding machine, and obtain the pressure demand adjustment value by subtracting it from the preset pressure reference value. If the pressure demand adjustment value is a positive number, the pressure of the injection molding machine is increased according to the pressure demand adjustment value. If the pressure demand adjustment value is a negative number, the pressure of the injection molding machine is decreased according to the pressure demand adjustment value, and the adjusted pressure of the injection molding machine is recorded as the injection molding machine adjustment pressure; The second step is to read the injection speed of the injection molding machine, and obtain the injection speed demand adjustment value by subtracting it from the preset injection speed reference value, and control the weight of the injection molding material output per unit time point of the injection molding machine according to the injection speed demand adjustment value, and sum the injection speed of the injection molding machine and the injection speed demand adjustment value to obtain the injection molding machine adjustment injection speed; The third step is to read the holding time of the injection molded part, and obtain the holding time requirement adjustment value by subtracting it from the preset holding time reference value. If the holding time requirement adjustment value is a positive number, the holding time of the injection molded part is increased according to the holding time requirement adjustment value. If the holding time requirement adjustment value is a negative number, the holding time of the injection molded part is reduced according to the holding time requirement adjustment value, and the adjusted holding time is recorded as the injection molding machine adjusted holding time.

8. The method for monitoring and optimizing warpage deformation during the injection molding process of automobile injection molded parts according to claim 7, characterized in that: The specific analysis method for rechecking the process requirement adjustment coefficient of automobile injection molding parts is as follows: The injection molding machine adjustment pressure, injection molding machine adjustment injection speed, and injection molding machine adjustment holding time are read respectively, and the process requirement adjustment coefficient of the automobile injection molding parts after process parameter adjustment is obtained according to the method of analyzing the process requirement adjustment coefficient of the automobile injection molding parts, and the process requirement adjustment coefficient is compared with the preset process requirement adjustment coefficient threshold again. If the process requirement adjustment coefficient of the automobile injection molding parts after process parameter adjustment is less than the preset process requirement adjustment coefficient threshold, it means that the process parameter adjustment is qualified, otherwise it means that the process parameter adjustment is unqualified, and the process parameters of the automobile injection molding parts are adjusted again until the process parameters are qualified.

9. The method for monitoring and optimizing warpage deformation during the injection molding process of automobile injection molded parts according to claim 1, characterized in that: The specific analysis method of the cooling analysis is: In the first step, several time points are selected during the cooling time of the injection molded part according to the set time interval, which are recorded as temperature time points. The injection molded part is divided into several areas according to the set area. At the same time, several equally spaced detection points are randomly selected in each area of ​​the injection molded part, which are recorded as temperature detection points. The temperature of each temperature time point in each area of ​​the injection molded part is obtained, and the temperature of each temperature time point in each area of ​​the injection molded part is obtained by taking the average value, which is recorded as x represents the number of the x-th temperature time point, x=1,2,...,y, a represents the number of the a-th area, a=1,2,...,b; In the second step, a two-dimensional coordinate system is constructed with the temperature time point as the horizontal coordinate and the temperature as the vertical coordinate, and then several points are marked in the constructed two-dimensional coordinate system for the temperature of each temperature time point in each area of ​​the injection molded part to form a temperature change curve of each area of ​​the injection molded part. The temperature change curves of each area of ​​the injection molded part are overlapped to obtain the overlapping degree of temperature change in the injection molded part area, and the overlapping degree is compared with the preset overlapping degree threshold. If the overlapping degree of temperature change in the injection molded part area is greater than or equal to the preset overlapping degree threshold, it means that there is no uneven cooling of the injection molded part. Otherwise, it means that there is uneven cooling of the injection molded part. It is regulated and the overlapping degree of temperature change in the injection molded part area after regulation is re-inspected.

10. The method for monitoring and optimizing warpage deformation during the injection molding process of automobile injection molded parts according to claim 9, characterized in that: The specific analysis method for re-inspecting the overlapping degree of temperature changes in the injection molded parts after adjustment is as follows: An adjustable flow control valve is installed in the pipeline of the cooling medium, and the flow rate is adjusted according to the demand. The temperature of each temperature time point in each area of ​​the injection molded part after regulation is obtained according to the previously set time interval, area division and detection point selection method. The overlapping degree of the temperature change in the injection molded part area after regulation is obtained by analyzing the degree of overlapping of the temperature change in the injection molded part area, and it is compared with the preset overlapping degree threshold again. If the overlapping degree of the temperature change in the injection molded part area after regulation is greater than or equal to the preset overlapping degree threshold, it means that there is no uneven cooling of the injection molded part after regulation. Otherwise, it means that there is still uneven cooling of the injection molded part after regulation, and it is regulated again until the overlapping degree of the temperature change in the injection molded part area is greater than or equal to the preset overlapping degree threshold.

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