An impact testing device based on power bank production and a method of using the same

Abstract

The application discloses an impact test device based on power bank production and a use method thereof, and relates to the technical field of power bank production. The impact test device based on power bank production comprises an impact execution mechanism, a clamping mechanism, a voiceprint acquisition module, an air pressure detection module and a data processing unit. The clamping mechanism fixes a power bank to be tested. The impact execution mechanism applies an impact with a predetermined energy. The voiceprint acquisition module acquires an acoustic signal generated by a shell at an instant of impact. The air pressure detection module detects an air pressure change amount of the shell before and after the impact. The data processing unit compares the acoustic signal with a reference voiceprint feature library, compares the air pressure change amount with a preset air pressure threshold, and comprehensively outputs a shell integrity determination result. The application realizes the evaluation of the structural integrity and sealing performance of the power bank shell after the impact through the combination of acoustic detection and air pressure detection, and improves the accuracy and reliability of the impact test of the power bank.

Description

Technical Field

[0001] This invention relates to the field of power bank manufacturing technology, specifically to an impact testing device based on power bank manufacturing and its usage method. Background Technology

[0002] As a backup power source, power banks may be accidentally dropped or impacted during transportation, carrying, or daily use. If the casing is damaged after an impact, it may lead to serious safety accidents such as short circuits, leakage, or even fire and explosion of the internal battery. Therefore, impact testing of power bank products during the production process to assess the integrity of the casing is a key step in ensuring product quality and user safety. Currently, the existing test method for impact testing of portable electronic products such as power banks usually adopts the free fall test method, which involves dropping the power bank from a preset height (such as 1.5m) onto a hard surface to simulate an actual drop scenario. After the test, inspectors observe the casing with the naked eye or a magnifying glass to see if there are visible defects such as cracks or deformation, and combine this with indicators such as whether the battery leaks, catches fire, and whether the electrical functions are normal to determine whether it is qualified.

[0003] However, the existing detection methods described above have the following problems in practical applications: First, visual inspection can only detect macroscopic cracks and obvious deformations exposed on the surface of the shell. Traditional visual inspection is not easy to identify micro-cracks or minor damage that are difficult to observe with the naked eye inside the shell. Second, existing impact tests mainly rely on manual observation and subjective judgment. The test results are greatly affected by the experience level and visual discrimination ability of the testers, lack objective quantitative data support, and make it difficult to achieve standardization and consistency of test results. Third, existing testing methods only focus on visible damage to the casing surface and basic battery functions, without quantitatively testing the sealing performance of the casing after impact. Subtle changes in the casing's sealing performance may indicate potential structural damage, which may gradually expand during subsequent use and eventually lead to safety failure. Therefore, there is an urgent need for a testing scheme that can objectively and quantitatively assess the structural integrity and sealing performance of the power bank casing after impact. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an impact testing device based on power bank manufacturing and its usage method, thereby solving the problems mentioned in the background section.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an impact testing device based on power bank manufacturing, comprising: Impact actuator, used to apply a predetermined energy impact to the power bank under test; A clamping mechanism is disposed in the impact area of ​​the impact actuator and is used to fix the power bank under test; An acoustic signature acquisition module is located near the impact actuator and is used to acquire the acoustic signal generated by the casing of the power bank under test at the moment of impact. The air pressure detection module is used to detect the change in air pressure inside the casing of the power bank under test before and after the impact. The data processing unit is connected to the voiceprint acquisition module and the air pressure detection module respectively. The data processing unit is configured to output a comprehensive judgment result of the shell integrity of the power bank under test based on the comparison result of the acoustic signal with the pre-stored reference voiceprint feature library and the comparison result of the air pressure change with the preset air pressure threshold.

[0006] Preferably, the voiceprint acquisition module includes a microphone array and a voiceprint preprocessing submodule. The microphone array consists of at least two high-sensitivity microphones arranged at a predetermined interval. The voiceprint preprocessing submodule is used to amplify, filter, and perform analog-to-digital conversion on the acoustic signals acquired by the microphone array.

[0007] Preferably, the reference acoustic signature library is stored in the memory of the data processing unit. The reference acoustic signature library includes a sub-library of acoustic signatures of an intact shell impact and a sub-library of acoustic signatures of a cracked shell impact. The sub-library of acoustic signatures of an intact shell impact contains spectral feature data of acoustic signals generated by a power bank with an intact shell when subjected to a predetermined energy impact. The sub-library of acoustic signatures of a cracked shell impact contains spectral feature data of acoustic signals generated by a power bank with a cracked shell when subjected to a predetermined energy impact.

[0008] Preferably, the data processing unit includes a voiceprint comparison module, which is configured to compare the acoustic signal processed by the voiceprint preprocessing submodule with the soundprint feature library of intact shell impact and the soundprint feature library of cracked shell impact, respectively. When the similarity between the acoustic signal and the soundprint feature library of intact shell impact is greater than or equal to a first similarity threshold, a first determination result of good shell condition is output; when the similarity between the acoustic signal and the soundprint feature library of cracked shell impact is greater than or equal to a second similarity threshold, a second determination result of cracked shell condition is output.

[0009] Preferably, the air pressure detection module includes an air pressure sensor and a sealed connection assembly. One end of the sealed connection assembly is sealed to the air input end of the air pressure sensor, and the other end of the sealed connection assembly is provided with a connection port that is detachably and sealed to the USB interface of the power bank under test. The air pressure sensor is connected to the inside of the casing of the power bank under test through the sealed connection assembly to detect the air pressure value inside the casing before and after the impact.

[0010] Preferably, the sealing connection assembly further includes an elastic sealing ring, which is sleeved on the outer peripheral wall of the connection port to form an airtight seal when the USB interface of the power bank under test is inserted into the connection port; the pressure sensor is a piezoresistive pressure sensor or a capacitive pressure sensor, and its detection accuracy is not less than ±0.1kPa.

[0011] Preferably, the data processing unit further includes a pressure comparison module, which is configured to acquire a first pressure value detected by the pressure sensor before the impact and a second pressure value detected after the impact, calculate the pressure change between the second pressure value and the first pressure value, and compare the pressure change with a preset pressure threshold. When the pressure change is less than or equal to the preset pressure threshold, a third determination result indicating good housing sealing is output; when the pressure change is greater than the preset pressure threshold, a fourth determination result indicating damaged housing sealing is output.

[0012] Preferably, the data processing unit further includes a comprehensive determination module, which is configured to receive the first determination result or the second determination result output by the voiceprint comparison module and the third determination result or the fourth determination result output by the air pressure comparison module, and output the comprehensive determination result of the shell integrity according to the following rules: When the voiceprint comparison module outputs the first determination result and the air pressure comparison module outputs the third determination result, the comprehensive determination module outputs a determination signal that the shell is intact and qualified. When the voiceprint comparison module outputs the second determination result and the air pressure comparison module outputs the third determination result, the comprehensive determination module outputs a determination signal indicating that the shell has microcracks. When the voiceprint comparison module outputs the first determination result and the air pressure comparison module outputs the fourth determination result, the comprehensive determination module outputs a determination signal indicating abnormal housing sealing. When the voiceprint comparison module outputs the second determination result and the air pressure comparison module outputs the fourth determination result, the comprehensive determination module outputs a determination signal that the housing is seriously unqualified.

[0013] Preferably, it also includes an alarm module, which is signal-connected to the data processing unit. The alarm module issues an alarm signal in response to the data processing unit outputting a comprehensive judgment result of the shell integrity that is unqualified.

[0014] This invention also discloses a method for using an impact testing device based on power bank manufacturing, applicable to the aforementioned impact testing device based on power bank manufacturing, comprising the following steps: Step S1: Fix the power bank to be tested to the impact area of ​​the impact actuator using the clamping mechanism, and connect the air pressure detection module to the inside of the power bank's casing; Step S2: The air pressure detection module detects and records the first air pressure value inside the casing of the power bank under test before the impact; Step S3: Activate the impact actuator to apply a predetermined energy impact to the power bank under test, and at the same time collect the acoustic signal generated by the shell of the power bank under test at the moment of impact through the acoustic fingerprint acquisition module; Step S4: After the impact is completed, the air pressure detection module detects and records the second air pressure value inside the casing of the power bank under test after the impact, and calculates the air pressure change between the second air pressure value and the first air pressure value. Step S5: The data processing unit compares the acoustic signal with the pre-stored reference acoustic signature feature library to obtain the acoustic signature determination result of the shell state, and compares the air pressure change with the preset air pressure threshold to obtain the air pressure determination result of the shell sealing performance. Step S6: The data processing unit outputs a comprehensive judgment result on the integrity of the casing of the power bank under test based on the combination of the voiceprint judgment result and the air pressure judgment result.

[0015] The technical effects and advantages of this invention are as follows: This impact testing device based on power bank manufacturing firstly applies a predetermined energy impact to the power bank under test through an impact actuator, and simultaneously sets up an acoustic fingerprint acquisition module to collect the acoustic signal generated by the shell at the moment of impact and an air pressure detection module to detect the change in air pressure inside the shell before and after the impact. The data processing unit outputs a comprehensive judgment on the integrity of the shell by combining the comparison results of the acoustic signal and the comparison results of the air pressure change. This realizes a multi-dimensional comprehensive detection of the integrity of the power bank shell and overcomes the defect that a single detection method is difficult to comprehensively assess the damage state of the shell.

[0016] Secondly, the acoustic signal generated by the impact of the power bank shell is collected by the microphone array of the acoustic acquisition module. The acoustic signal is then compared with the pre-stored acoustic feature sub-libraries of intact shell impact and cracked shell impact by the acoustic comparison module. This allows for accurate identification of micro-cracks and structural damage generated inside and on the surface of the shell during the impact. This enables objective quantitative detection of shell defects that are not visible to the naked eye, solving the problem that traditional visual inspection methods rely on human experience and are difficult to detect micro-cracks.

[0017] Third, the air pressure sensor is detachably and sealed to the USB interface of the power bank under test through the sealed connection component of the air pressure detection module. The change in air pressure inside the shell before and after the impact is detected, and the air pressure comparison module compares the change in air pressure with a preset air pressure threshold. This can accurately quantify and assess the degree of damage to the shell's sealing performance after the impact, providing an objective data dimension independent of appearance inspection for the comprehensive judgment of the shell's integrity. This solves the technical problem that existing detection methods cannot quantitatively assess changes in the shell's sealing performance. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the main view of the present invention; Figure 3 This is a schematic diagram showing the location of the sealing connection assembly of the present invention; Figure 4 This is a schematic diagram showing the location of the air pressure sensor of the present invention; Figure 5 This is a schematic diagram of the internal architecture of the voiceprint acquisition module of the present invention; Figure 6 This is a schematic diagram of the internal module relationships of the data processing unit of the present invention; Figure 7 This is a diagram illustrating the data flow and signal transmission architecture of the present invention. Figure 8 This is a flowchart of the method of the present invention.

[0020] In the diagram: 100, impact actuator; 200, clamping mechanism; 300, voiceprint acquisition module; 310, microphone array; 320, voiceprint preprocessing submodule; 400, air pressure detection module; 410, air pressure sensor; 420, sealing connection assembly; 421, connection port; 422, elastic sealing ring; 500, data processing unit; 510, voiceprint comparison module; 520, air pressure comparison module; 530, comprehensive judgment module; 600, alarm module; 700, power bank under test. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] This embodiment discloses an impact testing device based on power bank manufacturing, according to the attached... Figure 1 To be continued Figure 8 As shown, it includes an impact actuator 100, a clamping mechanism 200, an acoustic fingerprint acquisition module 300, an air pressure detection module 400, a data processing unit 500, and an alarm module 600.

[0023] According to the appendix Figure 1 and Figure 2 As shown, the impact actuator 100 is used to apply a predetermined energy impact to the power bank 700 under test. In this embodiment, the impact actuator 100 is preferably a pneumatic impact cylinder, which includes a cylinder body, a piston, an impact rod, an electromagnetic reversing valve, and a compressed air source. The piston is located inside the cylinder body, dividing the cylinder body into a rod chamber and a rodless chamber. One end of the impact rod is fixedly connected to the piston, and the other end extends out of the cylinder body and faces the impact area of ​​the clamping mechanism 200. The compressed air source is connected to the rod chamber and the rodless chamber respectively through the electromagnetic reversing valve. By controlling the opening and closing and reversing of the electromagnetic reversing valve, the piston is driven to drive the impact rod to move at high speed along the axial direction, thereby applying an instantaneous impact force to the power bank 700 under test. The magnitude of the predetermined energy is controlled by adjusting the air supply pressure of the compressed air source or the stroke of the piston. The air supply pressure adjustment range is 0.2MPa to 0.8MPa, and the stroke adjustment range is 10mm to 100mm.

[0024] According to the appendix Figure 1 and Figure 2As shown, the clamping mechanism 200 is disposed in the impact area of ​​the impact actuator 100 for fixing the power bank 700 under test. The clamping mechanism 200 includes a fixed base and an adjustable clamping assembly disposed on the fixed base. The adjustable clamping assembly includes an L-shaped clamping arm, which has a horizontal section and a vertical section. The horizontal section is located above the fixed base, and the lower surface of the horizontal section and the upper surface of the fixed base form a clamping space for accommodating the power bank 700 under test. The vertical section of the L-shaped clamping arm slides vertically with the fixed base via a guide rail. The L-shaped clamping arm is driven by an electric push rod to move vertically up and down to change the height of the clamping space, thereby adapting to power banks 700 of different thicknesses and achieving clamping and release. The lower surface of the horizontal section of the L-shaped clamping arm and the upper surface of the fixed base are both provided with elastic buffer pads. The elastic buffer pads are made of silicone rubber or polyurethane and are 2mm to 5mm thick. They are used to protect the shell surface of the power bank 700 under test during clamping. The fixed base is also provided with positioning bosses to ensure the consistency of the impact point position of the power bank 700 under test.

[0025] According to the appendix Figure 5 As shown, the voiceprint acquisition module 300 is located near the impact actuator 100 and is used to acquire the acoustic signal generated by the casing of the power bank 700 under test at the moment of impact. The voiceprint acquisition module 300 includes a microphone array 310 and a voiceprint preprocessing submodule 320. The microphone array 310 is composed of at least two high-sensitivity microphones arranged at a predetermined interval. Preferably, the microphone array 310 is composed of four high-sensitivity microphones arranged in a rectangular array, with the distance between adjacent microphones being 5cm to 15cm. The frequency response range of the high-sensitivity microphones is 20Hz to 20kHz, the sensitivity is not less than -40dBV / Pa, and the signal-to-noise ratio is not less than 6. The microphone array 310 is positioned 10cm to 50cm from the impact center of the impact actuator 100 to ensure that the acquired acoustic signal has a sufficient signal-to-noise ratio. The voiceprint preprocessing submodule 320 is used to amplify, filter, and perform analog-to-digital conversion on the acoustic signal acquired by the microphone array 310. The voiceprint preprocessing submodule 320 includes a preamplifier, a bandpass filter, and an analog-to-digital converter. The preamplifier has a gain of 20dB to 60dB, the bandpass filter has a passband frequency range of 500Hz to 20kHz, and the analog-to-digital converter has a sampling rate of not less than 44.1kHz and a quantization bit depth of not less than 16 bits.

[0026] The air pressure detection module 400 is used to detect the change in air pressure inside the casing of the power bank 700 under test before and after an impact. The air pressure detection module 400 includes an air pressure sensor 410 and a sealing connection assembly 420. One end of the sealing connection assembly 420 is sealed to the air input end of the air pressure sensor 410, and the other end of the sealing connection assembly 420 is provided with a connection port 421 that is detachably and sealed to the USB interface of the power bank 700 under test. The air pressure sensor 410 is connected to the inside of the casing of the power bank 700 under test through the sealing connection assembly 420 to detect the air pressure value inside the casing before and after an impact. The sealing connection assembly 420 also includes an elastic sealing ring 422, which is sleeved on... The outer peripheral wall of the connection port 421 is used to form an airtight seal when the USB interface of the power bank 700 under test is inserted into the connection port 421. The elastic sealing ring 422 is made of fluororubber or silicone rubber with a hardness of Shore A type 40 to 70 degrees. The pressure sensor 410 is a piezoresistive pressure sensor or a capacitive pressure sensor with a detection accuracy of not less than ±0.1 kPa, a range of 0 kPa to 200 kPa, and an operating temperature range of -20℃ to 85℃. Preferably, the sealing connection assembly 420 also includes a three-way valve, the three ports of which are respectively connected to the pressure sensor 410, the connection port 421, and the external atmosphere, for zero-point calibration of the pressure sensor 410 before testing.

[0027] According to the appendix Figure 6 and Figure 7 As shown, the data processing unit 500 is connected to the voiceprint acquisition module 300 and the air pressure detection module 400 respectively. The data processing unit 500 is configured to output a comprehensive judgment result of the shell integrity of the power bank 700 under test based on the comparison result of the acoustic signal with the pre-stored reference voiceprint feature library and the comparison result of the air pressure change with the preset air pressure threshold. The data processing unit 500 includes a voiceprint comparison module 510, an air pressure comparison module 520 and a comprehensive judgment module 530.

[0028] The reference acoustic signature library is stored in the memory of the data processing unit 500. The reference acoustic signature library includes a sub-library of acoustic signatures from an intact casing impact and a sub-library of acoustic signatures from a cracked casing impact. The intact casing impact acoustic signature library contains spectral characteristic data of the acoustic signal generated by a power bank with an intact casing when subjected to a predetermined energy impact. The cracked casing impact acoustic signature library contains spectral characteristic data of the acoustic signal generated by a power bank with a cracked casing when subjected to a predetermined energy impact. The spectral characteristic data includes time-domain characteristic parameters and frequency-domain characteristic parameters. The time-domain characteristic parameters include peak amplitude, rise time, decay time, and duration. The frequency domain characteristic parameters include power spectral density, dominant frequency components, and spectral centroid. The method for establishing the acoustic signature feature sub-libraries of intact shell impact and cracked shell impact is as follows: select at least 50 standard power bank samples with intact shells and at least 50 standard power bank samples with known-sized cracks in their shells, and conduct impact tests under the same test conditions. Collect the acoustic signals generated by each standard power bank sample at the moment of impact. After processing by the acoustic signature preprocessing sub-module 320, extract the spectral feature data, and use machine learning algorithms for classification and modeling to form the acoustic signature feature sub-libraries of intact shell impact and cracked shell impact.

[0029] The voiceprint comparison module 510 is configured to compare the acoustic signal processed by the voiceprint preprocessing submodule 320 with the soundprint feature library of intact shell impact and the soundprint feature library of cracked shell impact, respectively. The soundprint feature comparison uses a dynamic time warping algorithm or a cosine similarity algorithm to calculate the similarity. When the similarity between the acoustic signal and the soundprint feature library of intact shell impact is greater than or equal to a first similarity threshold, a first determination result of good shell condition is output. When the similarity between the acoustic signal and the soundprint feature library of cracked shell impact is greater than or equal to a second similarity threshold, a second determination result of cracked shell condition is output. The first and second similarity thresholds are both preset values. Preferably, the first similarity threshold is set to 0.85 and the second similarity threshold is set to 0.80. When the similarity between the acoustic signal and the soundprint feature library of intact shell impact is less than the first similarity threshold and the similarity between the acoustic signal and the soundprint feature library of cracked shell impact is less than the second similarity threshold, the voiceprint comparison module 510 outputs a fifth determination result of shell condition that cannot be determined.

[0030] The air pressure comparison module 520 is configured to acquire the first air pressure value detected by the air pressure sensor 410 before the impact and the second air pressure value detected after the impact, calculate the air pressure change between the second air pressure value and the first air pressure value, and compare the air pressure change with a preset air pressure threshold. The preset air pressure threshold is a critical value pre-set according to the shell sealing requirements. Preferably, the preset air pressure threshold is 0.5 kPa. When the air pressure change is less than or equal to the preset air pressure threshold, a third judgment result of good shell sealing is output; when the air pressure change is greater than the preset air pressure threshold, a fourth judgment result of damaged shell sealing is output. The physical principle is that if the shell of the power bank 700 under test cracks after the impact, the gas inside the shell is connected to the outside atmosphere through the crack, causing the internal air pressure to change. The magnitude of the air pressure change is positively correlated with the size and number of cracks.

[0031] The comprehensive judgment module 530 is configured to receive the first, second, or fifth judgment result output by the voiceprint comparison module 510, and the third or fourth judgment result output by the air pressure comparison module 520, and output the comprehensive judgment result of the shell integrity according to the following rules: When the voiceprint comparison module 510 outputs the first judgment result and the air pressure comparison module 520 outputs the third judgment result, the comprehensive judgment module 530 outputs a judgment signal that the shell is intact and qualified. When the voiceprint comparison module 510 outputs the second judgment result and the air pressure comparison module 520 outputs the third judgment result, the comprehensive judgment module 530 outputs a judgment signal indicating that there are microcracks in the shell. When the voiceprint comparison module 510 outputs the first judgment result and the air pressure comparison module 520 outputs the fourth judgment result, the comprehensive judgment module 530 outputs a judgment signal indicating abnormal housing sealing. When the voiceprint comparison module 510 outputs the second judgment result and the air pressure comparison module 520 outputs the fourth judgment result, the comprehensive judgment module 530 outputs a judgment signal that the shell is seriously unqualified. When the voiceprint comparison module 510 outputs the fifth judgment result, regardless of what judgment result the air pressure comparison module 520 outputs, the comprehensive judgment module 530 outputs a judgment signal indicating that the shell status needs to be re-inspected.

[0032] The alarm module 600 is connected to the data processing unit 500 via a signal. The alarm module 600 issues an alarm signal in response to the comprehensive judgment result of the housing integrity output by the data processing unit 500, which indicates that the housing is unqualified. The alarm module 600 includes an audible and visual alarm and a display screen. When the audible and visual alarm receives a judgment signal from the comprehensive judgment module 530 indicating that the housing has micro-cracks, the housing has abnormal sealing, the housing is seriously unqualified, or the housing condition needs to be re-inspected, the audible and visual alarm emits audible and visual alarm signals of different frequencies and colors. The display screen is used to display the judgment results of each module in real time.

[0033] The workflow of the present invention will be described in detail below with reference to specific embodiments: Example 1: In this example, a qualified power bank with an intact casing is used as the test sample, combined with the attached... Figure 1 To be continued Figure 8 The working process of the impact testing device is explained in detail.

[0034] First, the operator places the power bank 700 to be tested on the fixed base of the clamping mechanism 200, adjusting its position so that its impact point is aligned with the positioning boss to ensure consistent impact position for each test. Then, the electric push rod is activated, driving the L-shaped clamping arm to move vertically downwards along the guide rail. This allows the lower surface of the horizontal section of the L-shaped clamping arm to clamp the power bank 700 under test together with the upper surface of the fixed base. The clamping force is controlled by the stroke of the electric push rod, ideally resulting in approximately 30% compression deformation of the elastic buffer layer, ensuring reliable fixation without damage. Meanwhile, the connection port 421 of the sealing connection component 420 is inserted into the USB interface of the power bank 700 under test. After the elastic sealing ring 422 is deformed by pressure, it forms an airtight seal with the inner wall of the USB interface, so that the pressure sensor 410 is connected to the inside of the housing through the sealing connection component 420. After the connection is completed, the pressure sensor 410 is connected to the external atmosphere through the three-way valve for zero-point calibration. After calibration, the detection path is switched. After the reading stabilizes, the first air pressure value before the impact is recorded, for example, 101.3 kPa.

[0035] Once ready, the impact actuator 100 is activated. In this embodiment, a pneumatic impact cylinder is preferred. The compressed air supply pressure is set to 0.5 MPa. The electromagnetic reversing valve switches to allow compressed air to enter the rodless chamber, pushing the piston and impact rod to impact the surface of the power bank 700 under test at a speed of about 5 m / s. The applied impact energy is about 12.5 J. At the moment of impact, the microphone array 310 is simultaneously triggered to collect acoustic signals. The four microphones pick up the sound waves of the shell vibration and air propagation from different directions. The acoustic preprocessing submodule 320 amplifies the signal by 40 dB, performs bandpass filtering from 500 Hz to 20 kHz, and performs analog-to-digital conversion at a sampling rate of 44.1 kHz to generate a digital acoustic signal and transmit it to the data processing unit 500.

[0036] Immediately after the impact, the reading of the air pressure sensor 410 is read. After stabilization, the second air pressure value after the impact is recorded. For a qualified power bank with an intact casing, since the casing has not developed any cracks or deformations, the internal sealing structure remains intact, and there is no gas leakage channel, the second air pressure value remains basically unchanged. For example, if it is measured to be 101.4 kPa, the pressure change is only 0.1 kPa. At the same time, the voiceprint comparison module 510 uses a cosine similarity algorithm to compare the collected acoustic signal with the reference voiceprint feature library. The calculated similarity with the voiceprint feature sub-library of the intact casing impact is 0.92, which is greater than the first similarity threshold of 0.85. The similarity between the sound signature feature of the cracked shell impact and the feature of the cracked shell impact is 0.35, which is less than the second similarity threshold of 0.80. Therefore, the first judgment result of good shell condition is output. The air pressure comparison module 520 compares the air pressure change of 0.1 kPa with the preset air pressure threshold of 0.5 kPa. Since 0.1 < 0.5, the third judgment result of good shell sealing is output. The comprehensive judgment module 530 receives the first and third judgment results and outputs the final signal of "shell is complete and qualified" according to the judgment rules. The display screen of the alarm module 600 displays the green word "qualified" and the sound and light alarm does not activate. The power bank is judged to be a qualified product.

[0037] Example 2: In this example, a defective power bank with obvious cracks in its shell is used as the test sample. The preliminary preparation of the workflow is exactly the same as in Example 1, including clamping and fixing, sealing connection, zero-point calibration and recording of the first air pressure value before impact. The first air pressure value is also about 101.3 kPa. The pneumatic impact cylinder is activated, and the impact is carried out under the same parameters, while the acoustic signal is collected simultaneously.

[0038] After the impact, due to existing cracks in the shell or the impact causing the cracks to expand, the gas inside the shell connects with the external atmosphere through the cracks. The second air pressure value detected by the air pressure sensor 410 shows a significant drop, for example, measured as 100.6 kPa, with a pressure change of 0.7 kPa. The acoustic signature comparison module 510 analyzes the collected acoustic signal and finds that a significant high-frequency abnormal component was generated at the moment of impact. The spectral characteristics highly match the acoustic signature feature sub-library of the cracked shell impact, and the calculated similarity is 0.88, which is greater than the second similarity threshold of 0.80. However, the similarity with the intact shell sub-library is only 0.42, which is less than the first similarity threshold of 0.85. Therefore, the second judgment result of the shell having cracks is output. The air pressure comparison module 520 compares the air pressure change of 0.7 kPa with the preset threshold of 0.5 kPa. Since 0.7 > 0.5, the fourth judgment result of the shell sealing is damaged is output.

[0039] The comprehensive judgment module 530 receives the second and fourth judgment results and determines that the shell is seriously unqualified according to the preset rules. At this time, the display screen of the alarm module 600 displays the words "seriously unqualified" in red, and the audible and visual alarm emits a red flash and a continuous buzzing sound to remind the operator.

[0040] Example 3: In this example, a power bank with microcracks in the shell but no obvious damage to the sealing is used as the test sample. Such products usually have defects that are difficult to detect with the naked eye on the shell surface, but under impact stress, microcracks will release characteristic sound waves, which belongs to the early potential failure mode. The workflow also includes clamping and fixing, sealing connection, zero-point calibration and recording the first air pressure value before impact. The pneumatic impact cylinder implements the impact with the same parameters and simultaneously collects acoustic signals.

[0041] After the impact, the air pressure sensor 410 measured a second air pressure value of 101.1 kPa, with a pressure change of 0.2 kPa, which did not exceed the preset threshold of 0.5 kPa. This is because the microcrack is extremely small, the gas leakage rate inside the shell is very low, and the air pressure drop is not significant during the short test period. Therefore, air pressure detection alone cannot identify this type of defect. However, the microphone array 310 captured the weak high-frequency sound wave generated at the microcrack at the moment of impact. Its spectral characteristics have a similarity of 0.83 with the sound wave feature sub-library of the cracked shell impact, which is greater than the second similarity threshold of 0.80. However, its similarity with the intact shell sub-library is only 0.55, which is less than the first similarity threshold of 0.85. Therefore, the second judgment result of the shell having a crack is output. The air pressure comparison module 520 outputs a third judgment result of the shell having good sealing performance because the air pressure change of 0.2 kPa is less than 0.5 kPa.

[0042] The comprehensive judgment module 530 receives the second and third judgment results and outputs an intermediate state signal indicating that there are microcracks in the shell according to the judgment rules. The display screen of the alarm module 600 shows the words "microcracks exist" in yellow, the audible and visual alarm emits a yellow flash, without a buzzer, prompting the operator to move to a dedicated re-inspection station.

[0043] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An impact testing device based on power bank manufacturing, characterized in that, include: Impact actuator (100) is used to apply a predetermined energy impact to the power bank under test (700); A clamping mechanism (200) is disposed in the impact area of ​​the impact actuator (100) for fixing the power bank under test (700). The acoustic signature acquisition module (300) is located near the impact actuator (100) and is used to acquire the acoustic signal generated by the shell of the power bank under test (700) at the moment of impact. The air pressure detection module (400) is used to detect the change in air pressure inside the casing of the power bank under test (700) before and after the impact. The data processing unit (500) is connected to the voiceprint acquisition module (300) and the air pressure detection module (400) respectively. The data processing unit (500) is configured to output the comprehensive judgment result of the shell integrity of the power bank under test (700) based on the comparison result of the acoustic signal with the pre-stored reference voiceprint feature library and the comparison result of the air pressure change with the preset air pressure threshold.

2. The impact testing device based on power bank manufacturing according to claim 1, characterized in that, The voiceprint acquisition module (300) includes a microphone array (310) and a voiceprint preprocessing submodule (320). The microphone array (310) is composed of at least two high-sensitivity microphones arranged at a predetermined interval. The voiceprint preprocessing submodule (320) is used to amplify, filter and perform analog-to-digital conversion processing on the acoustic signals acquired by the microphone array (310).

3. The impact testing device based on power bank manufacturing according to claim 2, characterized in that, The reference acoustic signature library is stored in the memory of the data processing unit (500). The reference acoustic signature library includes an intact shell impact acoustic signature sub-library and a cracked shell impact acoustic signature sub-library. The intact shell impact acoustic signature sub-library contains the spectral feature data of the acoustic signal generated by a power bank with an intact shell when subjected to a predetermined energy impact. The cracked shell impact acoustic signature sub-library contains the spectral feature data of the acoustic signal generated by a power bank with a cracked shell when subjected to a predetermined energy impact.

4. The impact testing device based on power bank manufacturing according to claim 3, characterized in that, The data processing unit (500) includes a voiceprint comparison module (510), which is configured to compare the acoustic signal processed by the voiceprint preprocessing submodule (320) with the soundprint feature library of the intact shell impact and the soundprint feature library of the cracked shell impact, respectively. When the similarity between the acoustic signal and the soundprint feature library of the intact shell impact is greater than or equal to a first similarity threshold, a first determination result of good shell condition is output; when the similarity between the acoustic signal and the soundprint feature library of the cracked shell impact is greater than or equal to a second similarity threshold, a second determination result of the presence of a crack in the shell is output.

5. The impact testing device based on power bank manufacturing according to claim 1, characterized in that, The air pressure detection module (400) includes an air pressure sensor (410) and a sealing connection assembly (420). One end of the sealing connection assembly (420) is sealed to the air input end of the air pressure sensor (410), and the other end of the sealing connection assembly (420) is provided with a connection port (421) that is detachably and sealed to the USB interface of the power bank under test (700). The air pressure sensor (410) is connected to the inside of the housing of the power bank under test (700) through the sealing connection assembly (420) to detect the air pressure value inside the housing before and after the impact.

6. The impact testing device based on power bank manufacturing according to claim 5, characterized in that, The sealing connection assembly (420) further includes an elastic sealing ring (422), which is sleeved on the outer peripheral wall of the connection port (421) to form an airtight seal when the USB interface of the power bank under test (700) is inserted into the connection port (421); the pressure sensor (410) is a piezoresistive pressure sensor or a capacitive pressure sensor.

7. The impact testing device based on power bank manufacturing according to claim 5, characterized in that, The data processing unit (500) further includes a pressure comparison module (520), which is configured to acquire a first pressure value detected by the pressure sensor (410) before the impact and a second pressure value detected after the impact, calculate the pressure change between the second pressure value and the first pressure value, and compare the pressure change with a preset pressure threshold. When the pressure change is less than or equal to the preset pressure threshold, a third judgment result indicating good housing sealing is output; when the pressure change is greater than the preset pressure threshold, a fourth judgment result indicating damaged housing sealing is output.

8. The impact testing device based on power bank manufacturing according to claim 7, characterized in that, The data processing unit (500) further includes a comprehensive judgment module (530), which is configured to receive the first judgment result or the second judgment result output by the voiceprint comparison module (510) and the third judgment result or the fourth judgment result output by the air pressure comparison module (520), and output the comprehensive judgment result of the shell integrity according to the following rules: When the voiceprint comparison module (510) outputs the first determination result and the air pressure comparison module (520) outputs the third determination result, the comprehensive determination module (530) outputs a determination signal that the shell is complete and qualified. When the voiceprint comparison module (510) outputs the second determination result and the air pressure comparison module (520) outputs the third determination result, the comprehensive determination module (530) outputs a determination signal that there are microcracks in the shell; When the voiceprint comparison module (510) outputs the first determination result and the air pressure comparison module (520) outputs the fourth determination result, the comprehensive determination module (530) outputs a determination signal indicating abnormal housing sealing. When the voiceprint comparison module (510) outputs the second determination result and the air pressure comparison module (520) outputs the fourth determination result, the comprehensive determination module (530) outputs a determination signal that the housing is seriously unqualified.

9. The impact testing device based on power bank manufacturing according to claim 1, characterized in that, It also includes an alarm module (600), which is signal-connected to the data processing unit (500).

10. A method of using an impact testing device based on a power bank, applied to the impact testing device based on a power bank as described in any one of claims 1 to 9, characterized in that, Includes the following steps: Step S1: Fix the power bank (700) to be tested to the impact area of ​​the impact actuator (100) using the clamping mechanism (200), and connect the air pressure detection module (400) to the inside of the shell of the power bank (700) to be tested; Step S2: The air pressure detection module (400) detects and records the first air pressure value inside the casing of the power bank under test (700) before the impact; Step S3: Activate the impact actuator (100) to apply a predetermined energy impact to the power bank under test (700), and at the same time collect the acoustic signal generated by the shell of the power bank under test (700) at the moment of impact through the acoustic fingerprint acquisition module (300); Step S4: After the impact is completed, the air pressure detection module (400) detects and records the second air pressure value inside the shell of the power bank under test (700) after the impact, and calculates the air pressure change between the second air pressure value and the first air pressure value. Step S5: The data processing unit (500) compares the acoustic signal with the pre-stored reference acoustic signature feature library to obtain the acoustic signature determination result of the shell state, and compares the air pressure change with the preset air pressure threshold to obtain the air pressure determination result of the shell sealing performance. Step S6: The data processing unit (500) outputs a comprehensive judgment result of the shell integrity of the power bank under test (700) based on the combination of the voiceprint judgment result and the air pressure judgment result.

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