An intelligent monitoring method for porous acoustic blanket preparation

Abstract

The present application relates to sound absorbing blanket preparation technical field, especially to a kind of for porous sound absorbing blanket preparation Intelligent monitoring method, including, based on periodically obtaining the sound absorption coefficient of each detection block under different noise frequency determines the uniform characterization parameter of the shaped product;Based on the sound absorption uniform characterization parameter determines whether the preparation of the shaped product is qualified, when determining the preparation of the shaped product is abnormal, based on the reaction force of composite product to needling in needling opening process determines the pressure variation parameter for composite product, based on the pressure variation parameter adjusts the preparation parameter of the shaped product;The sound absorption uniformity of each region of porous sound absorbing blanket is monitored, and the preparation parameter is flexibly adjusted according to the sound absorption uniformity of each region of the determined product, so that the preparation efficiency of porous sound absorbing blanket is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sound-absorbing blanket preparation, and particularly to an intelligent monitoring method for porous sound-absorbing blanket preparation. BACKGROUND

[0002] With the rapid development of the automobile industry, people's requirements for automobiles are not only beautiful appearance, but also high comfort, functionality and noise resistance of interior decoration. During the driving process of the automobile, various noises will be transmitted into the vehicle cabin, causing noise pollution to the driver and passengers. Therefore, an interior sound-absorbing blanket is generally installed on the body sheet metal in the vehicle cabin to achieve sound insulation.

[0003] Chinese patent document CN201510447611.5 discloses a manufacturing process of a high-sound-absorbing automobile carpet. The carpet includes a surface PET layer, a polyester fiber, an intermediate PET layer and a back PE layer which are compounded together from top to bottom. The carpet product is obtained through secondary shaping. It can be seen that the above technical solution has the following problems: the sound absorption uniformity of each region of the porous sound-absorbing blanket is not monitored, so that the preparation parameters cannot be flexibly adjusted according to the sound absorption uniformity of each region of the determined product, and the preparation efficiency of the porous sound-absorbing blanket is affected. SUMMARY

[0004] Therefore, the present application provides an intelligent monitoring method for porous sound-absorbing blanket preparation to overcome the problem in the prior art that the sound absorption uniformity of each region of the porous sound-absorbing blanket is not monitored, so that the preparation parameters cannot be flexibly adjusted according to the sound absorption uniformity of each region of the determined product, and the preparation efficiency of the porous sound-absorbing blanket is affected.

[0005] To achieve the above-mentioned purpose, the present application provides an intelligent monitoring method for porous sound-absorbing blanket preparation, comprising:

[0006] S1, performing needle punching treatment on a first raw material to generate a surface layer;

[0007] S2, performing needle punching treatment on a second raw material to generate a bottom felt layer;

[0008] S3, compounding an intermediate layer on one side of the surface layer and compounding the bottom felt layer on one side of the intermediate layer to generate a composite product;

[0009] S4, performing needle punching and opening on the composite product to complete the opening treatment of the composite product;

[0010] S5, performing heating treatment on the opened product to obtain a shaped product;

[0011] S6, determining the shaped product periodically acquired as a test product, dividing the test product into a plurality of detection blocks, and determining a uniform characterization parameter of the shaped product based on sound absorption coefficients of the detection blocks at different noise frequencies;

[0012] S7, determining whether the preparation of the shaped product is qualified based on the uniform sound absorption characterization parameter, including,

[0013] When it is determined that the preparation of the shaped product is abnormal, determining a pressure variation parameter of the composite product based on the reaction force of the composite product to the needling in the needling and aperturing process, and adjusting the preparation parameters of the shaped product based on the pressure variation parameter, including adjusting the needling frequency in the generation of the base felt to a corresponding value, adjusting the needling and aperturing depth in the aperturing process to a corresponding value, and adjusting the needling and aperturing frequency in the aperturing process to a corresponding value.

[0014] Or, when it is determined that the preparation of the shaped product is qualified, continuing to use the current preparation parameters to complete the preparation of the shaped product.

[0015] Further, in the S6, the process of determining the uniform characterization parameter of the shaped product based on the sound absorption coefficients of the detection blocks at different noise frequencies includes:

[0016] calculating the variance of each sound absorption coefficient of each detection block at a single noise frequency, to obtain a sound absorption difference value corresponding to the single noise frequency;

[0017] solving the average value of each sound absorption difference value corresponding to each noise frequency to obtain the uniform characterization parameter;

[0018] In the S7, the process of determining whether the preparation of the shaped product is qualified based on the uniform sound absorption characterization parameter includes,

[0019] when the uniform sound absorption characterization parameter is less than or equal to a first preset uniform sound absorption characterization parameter, determining that the preparation of the shaped product is qualified, and continuing to use the current preparation parameters to complete the preparation of the shaped product;

[0020] when the uniform sound absorption characterization parameter is less than or equal to a second preset uniform sound absorption characterization parameter and greater than the first preset uniform sound absorption characterization parameter, determining whether the preparation of the shaped product is qualified in combination with the comprehensive sound absorption difference value;

[0021] when the uniform sound absorption characterization parameter is greater than the second preset uniform sound absorption characterization parameter, determining that the preparation of the shaped product is abnormal, determining a pressure variation parameter of the composite product based on the reaction force of the composite product to the needling in the needling and aperturing process, and adjusting the preparation parameters of the shaped product based on the pressure variation parameter.

[0022] Further, the process of determining whether the preparation of the shaped product is qualified in combination with the comprehensive sound absorption difference value includes:

[0023] solving the variance of each sound absorption difference corresponding to each noise frequency to obtain a comprehensive sound absorption difference value;

[0024] If the comprehensive sound absorption difference value is less than or equal to a preset comprehensive sound absorption difference value, the number of splits for the test product is adjusted to a corresponding value based on the comprehensive sound absorption difference value;

[0025] If the comprehensive sound absorption difference value is greater than the preset comprehensive sound absorption difference value, it is determined that the preparation of the finished product is abnormal, the pressure change parameter for the composite product is determined based on the reaction force of the composite product on the needle during the needle punching process, and the preparation parameters for the finished product are adjusted based on the pressure change parameter.

[0026] Further, the number of splits for the test product is adjusted to a corresponding value based on the comprehensive sound absorption difference value, wherein,

[0027] The increase in the number of splits is inversely proportional to the comprehensive sound absorption difference value.

[0028] Further, the process of determining the pressure change parameter for the composite product based on the reaction force of the composite product on the needle during the needle punching process includes:

[0029] Drawing a reaction force time domain curve based on the reaction force of the composite product on the needle obtained at each time node;

[0030] Solving the difference between the maximum value and the minimum value in the reaction force time domain curve to obtain the pressure change parameter.

[0031] Further, the process of adjusting the preparation parameters for the finished product based on the pressure change parameter includes:

[0032] If the pressure change parameter is less than or equal to a preset pressure change parameter, the preparation parameters for the finished product are adjusted based on the sound absorption difference of each noise frequency;

[0033] If the pressure change parameter is greater than the preset pressure change parameter, the needle punching frequency for the second raw material during the generation of the bottom felt layer is adjusted to a corresponding value based on the pressure change parameter.

[0034] Further, the needle punching frequency for the second raw material during the generation of the bottom felt layer is adjusted to a corresponding value based on the pressure change parameter, wherein,

[0035] The increase in the needle punching frequency for the second raw material is positively correlated with the pressure change parameter.

[0036] Further, the process of adjusting the preparation parameters for the finished product based on the sound absorption difference of each noise frequency includes:

[0037] The noise frequency corresponding to the maximum value in each sound absorption difference is determined as an abnormal frequency;

[0038] If the abnormal frequency is high-frequency noise or medium-frequency noise, the needling frequency in the opening processing process is adjusted to a corresponding value based on the sound absorption uniformity characterization parameter;

[0039] If the abnormal frequency is low-frequency noise, the needling opening depth in the opening processing process is adjusted to a corresponding value based on the sound absorption difference amount of the abnormal frequency.

[0040] Further, the needling opening frequency in the opening processing process is adjusted to a corresponding value based on the sound absorption uniformity characterization parameter, wherein,

[0041] The decrease amplitude of the needling opening frequency is proportional to the sound absorption uniformity characterization parameter.

[0042] Further, the needling opening depth in the opening processing process is adjusted to a corresponding value based on the sound absorption difference amount of the abnormal frequency, wherein,

[0043] The increase amplitude of the needling opening depth in the opening processing process is proportional to the sound absorption difference amount of the abnormal frequency.

[0044] Compared with the prior art, the beneficial effects of the present application are that the uniformity characterization parameter of the finished product is determined based on periodically obtaining the sound absorption coefficients of each detection block at different noise frequencies; whether the preparation of the finished product is qualified is determined based on the sound absorption uniformity characterization parameter, when it is determined that the preparation of the finished product is abnormal, the pressure change parameter of the composite product is determined based on the reaction force of the composite product to the needling in the needling opening process, the preparation parameters of the finished product are adjusted based on the pressure change parameter, including adjusting the needling frequency in the generation of the bottom felt to a corresponding value, adjusting the needling opening depth in the opening processing process to a corresponding value, and adjusting the needling opening frequency in the opening processing process to a corresponding value; the sound absorption uniformity of each region of the porous sound absorption blanket is monitored, and the preparation parameters are flexibly adjusted according to the determined sound absorption uniformity of each region of the product, thereby improving the preparation efficiency of the porous sound absorption blanket.

[0045] Further, whether the preparation of the shaped product is qualified is determined based on the sound absorption uniformity characteristic parameter, and a sound absorption difference amount is calculated, which represents the difference of each detection block at the corresponding noise frequency. The sound absorption difference amount is determined at a single noise frequency, and the lower the sound absorption difference amount, the more uniform the absorption effect of each detection block on the corresponding noise frequency. Various frequencies of noise exist during vehicle driving. The uniformity characteristic parameter is determined, which represents the sound absorption performance of the shaped product at different frequencies. The lower the uniformity characteristic parameter, the better the absorption effect of the material on various noises in actual application. When the sound absorption uniformity characteristic parameter is less than or equal to a first preset sound absorption uniformity characteristic parameter, the sound absorption capacity difference between the shaped product in each detection block is extremely small, and the quality of the shaped product is stable. In this case, it is determined that the preparation is qualified and the current preparation parameters are continuously used. When the sound absorption uniformity characteristic parameter is less than or equal to a second preset sound absorption uniformity characteristic parameter and greater than the first preset sound absorption uniformity characteristic parameter, the sound absorption uniformity of the product has a certain fluctuation. At this time, the comprehensive sound absorption difference value is further judged. The comprehensive sound absorption difference value represents the dispersion degree of the sound absorption difference amount corresponding to each noise frequency. Through the comprehensive sound absorption difference value, it is determined whether the sound absorption at each noise frequency is slightly abnormal or whether there is a single noise frequency whose sound absorption is significantly different between each detection block, resulting in a large sound absorption uniformity value. When the comprehensive sound absorption difference value is less than or equal to a preset comprehensive sound absorption difference value, the sound absorption performance of the product at different noise frequencies is relatively consistent, and the sound absorption difference at each noise frequency is relatively stable. At this time, the detection precision may be insufficient to sensitively identify the abnormality of the shaped product. At this time, the number of segmented products is adjusted to further optimize the detection precision. When the comprehensive sound absorption difference value is greater than the preset comprehensive sound absorption difference value, the sound absorption difference of the shaped product at different noise frequencies is large, and the preparation is abnormal. At this time, the pressure change parameter of the composite product is determined based on the reaction force of the composite product to the needling in the needling process, and the preparation parameters of the shaped product are adjusted based on the pressure change parameter. By determining the uniformity characteristic parameter, the sound absorption performance of the shaped product at different noise frequencies is quantified, so that the preparation parameters can be adjusted in time when the shaped product is abnormal, to ensure that various noise frequencies can be well absorbed. The problems in the preparation process are found in time, and the stability of the product quality is ensured. When the preparation is determined, the preparation parameters are adjusted in time, which improves the sound absorption quality of the shaped product and further improves the preparation efficiency of the porous sound absorption blanket.

[0046] Further, the preparation parameters of the shaped product are adjusted based on the pressure change parameter, which characterizes the fluctuation of the reaction force of the composite product to the needling in the needling process. The reaction force of the composite product to the needling reflects the resistance of the microstructure inside the material. The change of the reaction force is related to the entanglement degree of the fibers inside the material. The pressure change parameter is obtained by drawing the time-domain curve of the reaction force and calculating the difference between the maximum value and the minimum value, which reflects the dynamic change of the microstructure of the material in the needling process. When the pressure change parameter is greater than the preset pressure change parameter, the reaction force fluctuates greatly. The microstructure inside the material changes dramatically in the needling process due to the too tight or too loose entanglement of the fibers in the bottom felt layer. At this time, due to the unevenness of the bottom felt layer, there are local density differences, which cause the reflection and refraction of the sound wave in the propagation process, and the sound wave cannot be effectively absorbed and attenuated, thereby affecting the overall noise absorption effect, resulting in good absorption effect in some areas and poor absorption effect in some areas, making the noise absorption not stable and comprehensive. At this time, the needling frequency is increased, so that the fibers are more closely intertwined in the needling process, and the uniformity of the bottom felt is improved. When the pressure change parameter is less than or equal to the preset pressure change parameter, the preparation parameters of the shaped product are adjusted based on the sound absorption difference of each noise frequency; the noise frequency corresponding to the maximum value in each sound absorption difference is determined as the abnormal frequency, because the sound absorption difference at this frequency is the largest, which indicates that the sound absorption performance of the product at this frequency is unstable. When the abnormal frequency is high-frequency noise or medium-frequency noise, at this time, due to the too high needling frequency, the holes are too dense, which destroys the integrity of the sound absorption structure, reduces the reflection and scattering of the medium-high frequency sound wave between the fibers, and reduces the absorption capacity of the medium-high frequency noise. At this time, the needling hole frequency is adjusted to change the number of holes on the material surface, thereby improving the sound absorption performance of high frequency and medium frequency. When the abnormal frequency is low-frequency noise, at this time, due to the insufficient needling amplitude, the hole diameter is small, and the low-frequency sound wave is difficult to enter the hole and consume energy therein, resulting in unsatisfactory absorption effect of the low-frequency noise. At this time, the needling hole depth in the hole processing process is adjusted to the corresponding value, and the hole diameter is increased to realize the propagation and absorption of the low-frequency noise. The mechanical property change of the product in the needling process is monitored, which reflects the uniformity and stability of the internal structure of the product, and provides data basis for the abnormal situation of the product. When the shaped product is abnormal, the needling frequency and the hole depth are adjusted to optimize the structure and performance of the product, so as to improve the sound absorption performance of the product and make it more meet the needs of different acoustic environments; at the same time, the structural stability of the product is enhanced, and the preparation efficiency of the porous sound absorption blanket is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 The step flow chart of the intelligent monitoring method for the preparation of the porous sound absorption blanket according to the embodiment of the application;

[0048] Figure 2The logic decision diagram for determining whether the preparation of the shaped product is qualified based on the sound absorption uniformity characterization parameter. DETAILED DESCRIPTION

[0049] In order to make the objects and advantages of the present application clearer, the present application will be further described below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0050] The preferred embodiments of the present application will be described below with reference to the accompanying drawings. It should be understood by those skilled in the art that the embodiments are only used to explain the technical principles of the present application and are not used to limit the protection scope of the present application.

[0051] Please refer to Figure 1 and Figure 2 respectively, which are a step flow chart of the intelligent monitoring method for the porous sound absorption blanket preparation and a logic decision diagram for determining whether the preparation of the shaped product is qualified based on the sound absorption uniformity characterization parameter. The intelligent monitoring method for the porous sound absorption blanket preparation comprises the following steps.

[0052] S1, performing needle punching treatment on the first raw material to generate a surface layer;

[0053] S2, performing needle punching treatment on the second raw material to generate a bottom felt layer;

[0054] S3, compositing the middle layer on one side of the surface layer and compositing the bottom felt layer on one side of the middle layer to generate a composite product;

[0055] S4, performing needle punching and opening on the composite product to complete the opening treatment on the composite product;

[0056] S5, performing heating treatment on the product after opening to obtain a shaped product;

[0057] S6, determining the periodically obtained shaped product as a test product, dividing the test product into a plurality of detection blocks, and determining a uniform characterization parameter of the shaped product based on the sound absorption coefficients of the detection blocks under different noise frequencies;

[0058] S7, determining whether the preparation of the shaped product is qualified based on the sound absorption uniformity characterization parameter, comprising:

[0059] When it is determined that the preparation of the shaped product is abnormal, determining a pressure change parameter of the composite product based on the reaction force of the composite product to the needle punching in the needle punching and opening process, and adjusting the preparation parameters of the shaped product based on the pressure change parameter, including adjusting the needle punching frequency in the process of generating the bottom felt to a corresponding value, adjusting the needle punching and opening depth in the opening treatment process to a corresponding value, and adjusting the needle punching and opening frequency in the opening treatment process to a corresponding value.

[0060] Or, when it is determined that the preparation of the finished product is qualified, the current preparation parameters are continuously used to complete the preparation of the finished product.

[0061] Specifically, the surface layer is a non-woven fabric, the gram weight of the surface layer is 200 g / m2; the gram weight of the bottom felt layer is 750 g / m2; the gram weight of the middle layer is 50 g / m2.

[0062] Specifically, the specific material of the second raw material is not limited, which can be a fiber material, and details are not repeated.

[0063] Specifically, in the S6, the specific way of determining the sound absorption coefficients of each detection block under different noise frequencies is not limited, the detection block can be placed in a standing wave tube, and the sound absorption coefficients of the detection block under different frequencies are measured, which is prior art and details are not repeated.

[0064] Specifically, the noise frequencies used to determine the sound absorption coefficients include high-frequency noise, medium-frequency noise, and low-frequency noise, and the specific frequencies of the high-frequency noise, medium-frequency noise, and low-frequency noise are not limited. In this example, preferably, the high-frequency noise is 3000 Hz, the medium-frequency noise is 1000 Hz, and the low-frequency noise is 100 Hz.

[0065] Specifically, the uniform representation parameters of the finished product are determined based on periodically obtaining the sound absorption coefficients of each detection block under different noise frequencies; whether the preparation of the finished product is qualified is determined based on the sound absorption uniformity representation parameters; when it is determined that the preparation of the finished product is abnormal, the pressure change parameter of the composite product is determined based on the reaction force of the composite product to the needling during the needling and opening process; the preparation parameters of the finished product are adjusted based on the pressure change parameter, including adjusting the needling frequency during the generation of the bottom felt to a corresponding value, adjusting the needling opening depth during the opening process to a corresponding value, and adjusting the needling opening frequency during the opening process to a corresponding value; the sound absorption uniformity of each region of the porous sound absorption blanket is monitored, and the preparation parameters are flexibly adjusted according to the determined sound absorption uniformity of each region of the product, thereby improving the preparation efficiency of the porous sound absorption blanket.

[0066] Specifically, in the S6, the process of determining the uniform representation parameters of the finished product based on the sound absorption coefficients of each detection block under different noise frequencies includes:

[0067] The variance of each sound absorption coefficient of each detection block under a single noise frequency is calculated to obtain a sound absorption difference quantity corresponding to the single noise frequency;

[0068] The average value of each sound absorption difference quantity corresponding to each noise frequency is solved to obtain the uniform representation parameter;

[0069] In the S7, the process of determining whether the preparation of the finished product is qualified based on the sound absorption uniformity representation parameters includes,

[0070] When the sound absorption uniformity characteristic parameter is less than or equal to the first preset sound absorption uniformity characteristic parameter, it is determined that the preparation of the shaped product is qualified, and the preparation of the shaped product is continued using the current preparation parameters;

[0071] When the sound absorption uniformity characteristic parameter is less than or equal to the second preset sound absorption uniformity characteristic parameter and greater than the first preset sound absorption uniformity characteristic parameter, it is determined whether the preparation of the shaped product is qualified in combination with the comprehensive sound absorption difference value;

[0072] When the sound absorption uniformity characteristic parameter is greater than the second preset sound absorption uniformity characteristic parameter, it is determined that the preparation of the shaped product is abnormal, a pressure change parameter for the composite product is determined based on the reaction force of the composite product on the needle punching in the needle punching process, and the preparation parameters for the shaped product are adjusted based on the pressure change parameter.

[0073] Specifically, the first preset sound absorption uniformity characteristic parameter J1 is selected in the interval [0.03, 0.04], and the second preset sound absorption uniformity characteristic parameter J2 is selected in the interval [0.06, 0.09].

[0074] Specifically, the process of determining whether the preparation of the shaped product is qualified in combination with the comprehensive sound absorption difference value includes:

[0075] Solving the variance of each sound absorption difference corresponding to each noise frequency to obtain the comprehensive sound absorption difference value;

[0076] If the comprehensive sound absorption difference value is less than or equal to the preset comprehensive sound absorption difference value, the number of the split for the test product is adjusted to the corresponding value based on the comprehensive sound absorption difference value;

[0077] If the comprehensive sound absorption difference value is greater than the preset comprehensive sound absorption difference value, it is determined that the preparation of the shaped product is abnormal, a pressure change parameter for the composite product is determined based on the reaction force of the composite product on the needle punching in the needle punching process, and the preparation parameters for the shaped product are adjusted based on the pressure change parameter.

[0078] Specifically, the preset comprehensive sound absorption difference value Z0 is selected in the interval [0.005, 0.015].

[0079] Specifically, whether the preparation of the shaped product is qualified is determined based on the sound absorption uniformity characteristic parameter, and a sound absorption difference amount is calculated, which represents the difference of each detection block at the corresponding noise frequency. The sound absorption difference amount is used to determine the sound absorption difference of the sound absorption blanket at a single noise frequency. The lower the sound absorption difference amount, the more uniform the absorption effect of each detection block on the corresponding noise frequency. Various frequencies of noise may exist during the driving of the vehicle. The sound absorption uniformity characteristic parameter is determined, which represents the sound absorption performance of the shaped product at different frequencies. The lower the sound absorption uniformity characteristic parameter, the better the absorption effect of the material on various noises in actual application. When the sound absorption uniformity characteristic parameter is less than or equal to a first preset sound absorption uniformity characteristic parameter, the sound absorption capacity difference between the shaped product in each detection block is extremely small, and the quality of the shaped product is stable. In this case, it is determined that the preparation is qualified and the current preparation parameters are continuously used. When the sound absorption uniformity characteristic parameter is less than or equal to a second preset sound absorption uniformity characteristic parameter and greater than the first preset sound absorption uniformity characteristic parameter, the sound absorption uniformity of the product has a certain fluctuation. In this case, the comprehensive sound absorption difference value is further determined in combination. The comprehensive sound absorption difference value represents the dispersion degree of the sound absorption difference amount corresponding to each noise frequency. The comprehensive sound absorption difference value is used to determine whether the sound absorption at each noise frequency is slightly abnormal or whether there is a single noise frequency whose sound absorption is significantly different between each detection block, resulting in a large sound absorption uniformity characteristic value. When the comprehensive sound absorption difference value is less than or equal to a preset comprehensive sound absorption difference value, the sound absorption performance of the product at different noise frequencies is relatively consistent, and the sound absorption difference at each noise frequency is relatively stable. In this case, the detection precision may be insufficient to accurately identify the abnormality of the shaped product. In this case, the segmentation number of the test product is adjusted to further optimize the detection precision. When the comprehensive sound absorption difference value is greater than the preset comprehensive sound absorption difference value, the sound absorption difference of the shaped product at different noise frequencies is large, and the preparation is abnormal. In this case, the pressure change parameter of the composite product is determined based on the reaction force of the composite product to the needling during the needling process, and the preparation parameters of the shaped product are adjusted based on the pressure change parameter. The sound absorption performance of the shaped product at different noise frequencies is quantified by determining the uniformity characteristic parameter, so that the preparation parameters can be adjusted in time when the shaped product is abnormal, to ensure that various noise frequencies can be well absorbed. The problems in the preparation process can be found in time, and the stability of the product quality is ensured. When the preparation is determined, the preparation parameters are adjusted in time, which improves the sound absorption quality of the shaped product and further improves the preparation efficiency of the porous sound absorption blanket.

[0080] Specifically, the segmentation number of the test product is adjusted to a corresponding value based on the comprehensive sound absorption difference value, wherein,

[0081] The increase range of the segmentation number is inversely proportional to the comprehensive sound absorption difference value.

[0082] In the embodiment, the segmentation number of the test product is adjusted to a corresponding value based on the comprehensive sound absorption difference value, wherein,

[0083] The comprehensive sound absorption difference value is compared with a first preset comprehensive sound absorption ratio threshold and a second preset comprehensive sound absorption ratio threshold.

[0084] If the comprehensive sound absorption difference value is less than or equal to the first preset comprehensive sound absorption ratio threshold, the number of divisions of the test product is adjusted to 1.3 times the initial number of divisions.

[0085] If the comprehensive sound absorption difference value is less than or equal to the second preset comprehensive sound absorption ratio threshold and greater than the first preset comprehensive sound absorption ratio threshold, the number of divisions of the test product is adjusted to 1.2 times the initial number of divisions.

[0086] If the comprehensive sound absorption difference value is greater than the second preset comprehensive sound absorption ratio threshold, the number of divisions of the test product is adjusted to 1.1 times the initial number of divisions.

[0087] The first preset comprehensive sound absorption ratio threshold is 0.4Z0, and the second preset comprehensive sound absorption ratio threshold is 0.7Z0.

[0088] Specifically, the number of divisions of the test product is the number of detection blocks obtained after the test product is divided in S6.

[0089] Specifically, after the adjustment of the number of divisions is completed, the adjusted number of divisions is compared with a preset maximum number of divisions; when the adjusted number of divisions is less than or equal to the preset maximum number of divisions, a plurality of detection blocks are re-acquired according to the number of divisions, and whether the preparation of the finished product is qualified is determined based on the re-acquired sound absorption uniformity representation parameters.

[0090] When the adjusted number of divisions is greater than the preset maximum number of divisions, the preset maximum number of divisions is used as the basis for obtaining the detection blocks; and the first preset sound absorption uniformity representation parameter is adjusted to a corresponding value.

[0091] After the adjustment of the first preset sound absorption uniformity representation parameter is completed, the process of determining whether the preparation of the finished product is qualified based on the sound absorption uniformity representation parameters is re-performed, and when the sound absorption uniformity representation parameter is greater than the adjusted second preset sound absorption uniformity representation parameter, it is determined that the preparation of the finished product is abnormal, the pressure change parameter of the composite product is determined based on the reaction force of the composite product to the needling in the needling process, and the preparation parameters of the finished product are adjusted based on the pressure change parameter.

[0092] In this embodiment, the first preset sound absorption uniformity representation parameter is optionally adjusted to 1.2 times the initial first preset sound absorption uniformity representation parameter.

[0093] Specifically, the preset maximum number of divisions is selected within the interval [30, 50].

[0094] Specifically, the process of determining the pressure variation parameter of the composite product based on the reaction force of the composite product to the needling in the needling opening process comprises:

[0095] Drawing a reaction force time domain curve based on the reaction force of the composite product to the needling obtained at each time node;

[0096] Solving the difference between the maximum value and the minimum value in the reaction force time domain curve to obtain the pressure variation parameter.

[0097] Specifically, the specific manner of obtaining the reaction force of the composite product to the needling in the needling opening process is not limited, which can be obtained by a pressure sensor arranged at a corresponding position of the needling opening device, and the position can be between the needling plate and the driving shaft driving the needling plate.

[0098] Specifically, the process of adjusting the preparation parameters of the finished product based on the pressure variation parameter comprises:

[0099] If the pressure variation parameter is less than or equal to the preset pressure variation parameter, the preparation parameters of the finished product are adjusted based on the sound absorption difference amount of each noise frequency;

[0100] If the pressure variation parameter is greater than the preset pressure variation parameter, the needling frequency of the second raw material in the process of generating the bottom felt layer is adjusted to a corresponding value based on the pressure variation parameter.

[0101] Specifically, the preset pressure variation parameter B0 is selected within the interval [1.3L0, 1.7L0], and L0 is the average value of the pressure variation parameters of a plurality of finished products determined to be prepared qualified in the selected historical data.

[0102] Specifically, the needling frequency of the second raw material in the process of generating the bottom felt layer is adjusted to a corresponding value based on the pressure variation parameter, wherein,

[0103] The increase amplitude of the needling frequency of the second raw material is positively correlated with the pressure variation parameter.

[0104] In the embodiment, optionally,

[0105] The pressure variation parameter is compared with a first preset pressure comparison threshold and a second preset pressure comparison threshold;

[0106] If the pressure variation parameter is less than or equal to the first preset pressure comparison threshold, the needling frequency of the second raw material is adjusted to 1.11 times the initial needling frequency;

[0107] If the pressure variation parameter is less than or equal to the second preset pressure comparison threshold and greater than the first preset pressure comparison threshold, the needling frequency of the second raw material is adjusted to 1.19 times the initial needling frequency;

[0108] If the pressure change parameter is greater than the second preset pressure ratio threshold, the needle punching frequency of the second raw material is adjusted to 1.28 times of the initial needle punching frequency;

[0109] The first preset pressure ratio threshold is 1.4B0, and the second preset pressure ratio threshold is 1.9B0.

[0110] Specifically, the process of adjusting the preparation parameters of the shaped product based on the sound absorption difference of each noise frequency includes:

[0111] The noise frequency corresponding to the maximum value of each sound absorption difference is determined as an abnormal frequency;

[0112] If the abnormal frequency is a high-frequency noise or a medium-frequency noise, the needle punching frequency in the opening treatment process is adjusted to a corresponding value based on the sound absorption uniformity parameter;

[0113] If the abnormal frequency is a low-frequency noise, the needle punching depth in the opening treatment process is adjusted to a corresponding value based on the sound absorption difference of the abnormal frequency.

[0114] Specifically, the preparation parameters of the shaped product are adjusted based on the pressure change parameter, which characterizes the fluctuation of the reaction force of the composite product to needling in the needling process. The reaction force of the composite product to needling reflects the resistance of the microstructure inside the material. The change of the reaction force is related to the entanglement degree of the fibers inside the material. The pressure change parameter is obtained by drawing the time-domain curve of the reaction force and calculating the difference between the maximum value and the minimum value, which reflects the dynamic change of the microstructure of the material in the needling process. When the pressure change parameter is greater than the preset pressure change parameter, the reaction force fluctuates greatly. Because the fibers of the bottom felt layer are too tightly or loosely entangled, the microstructure inside the material changes dramatically during the needling process. At this time, due to the unevenness of the bottom felt layer, there are local density differences, which cause the sound waves to encounter uneven structures during propagation, resulting in reflection and refraction, and cannot be effectively absorbed and attenuated, thereby affecting the overall noise absorption effect, resulting in some areas having good absorption effect, while some areas having poor absorption, making the noise absorption not stable and comprehensive. At this time, the needling frequency is increased, so that the fibers are more tightly intertwined during the needling process, and the uniformity of the bottom felt is improved. When the pressure change parameter is less than or equal to the preset pressure change parameter, the preparation parameters of the shaped product are adjusted based on the sound absorption difference of each noise frequency; the noise frequency corresponding to the maximum value in each sound absorption difference is determined as the abnormal frequency, because the sound absorption difference at this frequency is the largest, which indicates that the sound absorption performance of the product at this frequency is unstable. When the abnormal frequency is high-frequency noise or medium-frequency noise, at this time, due to the too high needling frequency, the holes are too dense, which destroys the integrity of the sound absorption structure, reduces the reflection and scattering of medium-high frequency sound waves between the fibers, and reduces the absorption capacity of medium-high frequency noise. At this time, the needling hole frequency is adjusted to change the number of holes on the material surface, thereby improving the sound absorption performance of high frequency and medium frequency. When the abnormal frequency is low-frequency noise, at this time, due to the insufficient needling amplitude, the hole diameter is small, and the low-frequency sound waves are difficult to enter the hole and consume energy therein, resulting in unsatisfactory absorption effect of low-frequency noise. At this time, the needling hole depth in the hole processing process is adjusted to the corresponding value, and the hole diameter is increased to realize the propagation and absorption of low-frequency noise. The change of the mechanical properties of the product in the needling process is monitored, which reflects the uniformity and stability of the internal structure of the product, and provides data basis for the abnormal situation of the product. When the shaped product is abnormal, the needling frequency and the hole depth are adjusted to optimize the structure and performance of the product, so as to improve the sound absorption performance of the product and make it more meet the needs of different acoustic environments; at the same time, the structural stability of the product is enhanced, and the preparation efficiency of the porous sound absorption blanket is further improved.

[0115] Specifically, the needling hole frequency in the hole processing process is adjusted to the corresponding value based on the sound absorption uniformity parameter, wherein,

[0116] The reduction amplitude of the needling hole frequency is proportional to the sound absorption uniformity parameter.

[0117] In the embodiment, optionally,

[0118] The sound absorption uniformity parameter is compared with a first preset uniformity comparison threshold and a second preset uniformity comparison threshold;

[0119] If the sound absorption uniformity parameter is less than or equal to the first preset uniformity comparison threshold, the needling hole frequency in the hole processing process is adjusted to 0.92 times the initial needling hole frequency;

[0120] If the sound absorption uniformity parameter is less than or equal to the second preset uniformity comparison threshold and greater than the first preset uniformity comparison threshold, the needling hole frequency in the hole processing process is adjusted to 0.82 times the initial needling hole frequency;

[0121] If the sound absorption uniformity parameter is greater than the second preset uniformity comparison threshold, the needling hole frequency in the hole processing process is adjusted to 0.72 times the initial needling hole frequency;

[0122] The first preset uniformity comparison threshold is 1.3J2, and the second preset uniformity comparison threshold is 1.4J2.

[0123] Specifically, the needling hole depth in the hole processing process is adjusted to a corresponding value based on the sound absorption difference of the abnormal frequency, wherein,

[0124] The increase range of the needling hole depth in the hole processing process is proportional to the sound absorption difference of the abnormal frequency.

[0125] In the embodiment, optionally,

[0126] The sound absorption difference of the abnormal frequency is compared with a first preset sound absorption difference comparison value and a second preset sound absorption difference comparison value;

[0127] If the sound absorption difference of the abnormal frequency is less than or equal to the first preset sound absorption difference comparison value, the depth of the needling hole in the hole processing process is increased to 1.12 times the initial needling hole depth;

[0128] If the sound absorption difference of the abnormal frequency is less than or equal to the second preset sound absorption difference comparison value and greater than the first preset sound absorption difference comparison value, the depth of the needling hole in the hole processing process is increased to 1.21 times the initial needling hole depth;

[0129] If the sound absorption difference of the abnormal frequency is greater than the second preset sound absorption difference comparison value, the depth of the needling hole in the hole processing process is increased to 1.28 times the initial needling hole depth;

[0130] The first preset sound absorption difference comparison value is 1.4J, and the second preset sound absorption difference comparison value is 1.9J, J being the uniformity parameter.

[0131] So far, the technical solutions of the present application have been described in combination with the preferred embodiments shown in the drawings, but it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical solutions after the changes or replacements will all fall within the protection scope of the present application.

[0132] The above only describes the preferred embodiments of the present application and is not intended to limit the present application; the present application can have various changes and variations for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A smart monitoring method for the preparation of porous sound-absorbing blankets, characterized in that, include: S1, The first raw material is needle-punched to generate a surface layer; S2, needle-punching the second raw material to generate a base felt layer; S3, the intermediate layer is laminated to one side of the surface layer, and the base felt layer is laminated to one side of the intermediate layer to form a composite product; S4, perform needle punching to open holes in the composite product to complete the opening process of the composite product; S5, heat-treat the product after opening to obtain a shaped product; S6, the periodically acquired finalized products are identified as inspection products, the inspection products are divided into several test blocks, and the uniform characterization parameters of the finalized products are determined based on the sound absorption coefficients of each test block at different noise frequencies. This includes calculating the variance of the sound absorption coefficients of each test block at a single noise frequency to obtain the sound absorption difference for a single noise frequency; and solving for the average value of the sound absorption difference for each noise frequency to obtain the uniform characterization parameters. S7, Determine whether the preparation of the finalized product is qualified based on the sound absorption uniformity characterization parameters, including, When an anomaly is identified in the preparation of the final product, the pressure change parameter for the composite product is determined based on the reaction force of the composite product on the needle punching during the needle punching and opening process. The preparation parameters for the final product are adjusted based on the pressure change parameter, including adjusting the needle punching frequency in the process of generating the bottom felt to the corresponding value, adjusting the needle punching and opening depth in the opening process to the corresponding value, and adjusting the needle punching and opening frequency in the opening process to the corresponding value. Alternatively, once it is determined that the preparation of the finalized product is qualified, the current preparation parameters can be used to complete the preparation of the finalized product.

2. The intelligent monitoring method for preparing porous sound-absorbing blankets according to claim 1, characterized in that, In S7, the process of determining whether the preparation of the finalized product is qualified based on the sound absorption uniformity characterization parameters includes, When the sound absorption uniformity characterization parameter is less than or equal to the first preset sound absorption uniformity characterization parameter, the preparation of the finalized product is determined to be qualified, and the current preparation parameters are used to complete the preparation of the finalized product. When the sound absorption uniformity characterization parameter is less than or equal to the second preset sound absorption uniformity characterization parameter and greater than the first preset sound absorption uniformity characterization parameter, the overall sound absorption difference value is combined to determine whether the preparation of the finalized product is qualified. When the sound absorption uniformity characterization parameter is greater than the second preset sound absorption uniformity characterization parameter, an abnormality in the preparation of the shaped product is determined. Based on the reaction force of the composite product on the needle punch during the needle punching process, the pressure change parameter for the composite product is determined, and the preparation parameters for the shaped product are adjusted based on the pressure change parameter.

3. The intelligent monitoring method for preparing porous sound-absorbing blankets according to claim 2, characterized in that, The process of determining whether the preparation of a finalized product is qualified based on the comprehensive sound absorption difference value includes: The variance of each sound absorption difference corresponding to each noise frequency is calculated to obtain the comprehensive sound absorption difference value. If the overall sound absorption difference value is less than or equal to the preset overall sound absorption difference value, the number of samples to be divided will be adjusted to the corresponding value based on the overall sound absorption difference value. If the overall sound absorption difference value is greater than the preset overall sound absorption difference value, it is determined that the preparation of the final product is abnormal. Based on the reaction force of the composite product on the needle punching process, the pressure change parameter for the composite product is determined, and the preparation parameters for the final product are adjusted based on the pressure change parameter.

4. The intelligent monitoring method for preparing porous sound-absorbing blankets according to claim 3, characterized in that, The number of samples to be divided will be adjusted to the corresponding value based on the overall sound absorption difference value. The increase in the number of segments is inversely proportional to the overall sound absorption difference value.

5. The intelligent monitoring method for preparing porous sound-absorbing blankets according to claim 4, characterized in that, The process of determining the pressure change parameters for the composite product based on the reaction force of the composite product on the needle punch during the needle punching process includes: The reaction force time-domain curves of the composite product on the acupuncture were plotted based on the reaction force obtained at each time point. The pressure change parameter is obtained by solving for the difference between the maximum and minimum values ​​in the time-domain curve of the reaction force.

6. The intelligent monitoring method for preparing porous sound-absorbing blankets according to claim 5, characterized in that, The process of adjusting the preparation parameters of a finalized product based on pressure change parameters includes: If the pressure change parameter is less than or equal to the preset pressure change parameter, the preparation parameters of the finalized product are adjusted based on the sound absorption difference of each noise frequency. If the pressure change parameter is greater than the preset pressure change parameter, the needle punching frequency of the second raw material during the generation of the base felt layer will be adjusted to the corresponding value based on the pressure change parameter.

7. The intelligent monitoring method for preparing porous sound-absorbing blankets according to claim 6, characterized in that, Based on the pressure change parameter, the needle punching frequency of the second raw material during the generation of the base felt layer is adjusted to a corresponding value, wherein... The increase in the needle puncture frequency of the second raw material is positively correlated with the pressure change parameter.

8. The intelligent monitoring method for preparing porous sound-absorbing blankets according to claim 7, characterized in that, The process of adjusting the manufacturing parameters of the finalized product based on the sound absorption differences at various noise frequencies includes: The noise frequency corresponding to the maximum value among the various sound absorption differences is determined as the abnormal frequency; If the abnormal frequency is high-frequency noise or mid-frequency noise, the needle punching frequency during the hole opening process will be adjusted to the corresponding value based on the sound absorption uniformity characterization parameter. If the abnormal frequency is low-frequency noise, the needle punching depth during the hole-making process will be adjusted to the corresponding value based on the sound absorption difference of the abnormal frequency.

9. The intelligent monitoring method for preparing porous sound-absorbing blankets according to claim 8, characterized in that, Based on the sound absorption uniformity characterization parameters, the needle punching frequency during the hole-opening process is adjusted to a corresponding value, wherein, The decrease in the frequency of needle-punched openings is proportional to the sound absorption uniformity characterization parameter.

10. The intelligent monitoring method for preparing porous sound-absorbing blankets according to claim 9, characterized in that, Based on the difference in sound absorption at abnormal frequencies, the needle-punching depth during the perforation process is adjusted to a corresponding value, wherein... The increase in the needle-punching depth during the pore-opening process is directly proportional to the difference in sound absorption at abnormal frequencies.

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