A natural frequency tester and a natural frequency testing method

Abstract

This invention relates to the field of mechanical measurement technology, specifically to a natural frequency tester and a natural frequency testing method. The natural frequency tester includes: a clamping assembly for clamping a test piece; at least one signal generator for applying vibration excitation to the test piece in a preset manner; at least one vibration sensor for acquiring the excitation signal from the test piece; and a detection control chamber connected to the vibration sensor signal, used to calculate the natural frequency value of the test piece based on the excitation signal. This application, by setting a controllable signal generator on the clamping assembly, allows the operator to automatically control the vibration excitation of the test piece via a switch, avoiding errors during manual hammering. Furthermore, the tester body of this application includes an analyzer for rapid data processing. This achieves rapid measurement of the natural frequency and improves measurement efficiency.

Description

Technical Field

[0001] This invention relates to the field of mechanical measurement technology, specifically to a natural frequency tester and a natural frequency testing method. Background Technology

[0002] The study and analysis of mechanical vibration is a widely applied research direction in mechanical design and application. The magnitude of vibration not only affects the lifespan and stability of a system, but can also generate significant noise. Therefore, the study of vibration has very important theoretical and practical significance. Natural frequency testing is the most common method for solving automotive vibration and noise problems. Existing testing methods obtain this information through vibration testing and analysis systems. These systems generally consist of software and hardware. The software includes acquisition and analysis modules, while the hardware includes a data acquisition system front-end, sensors, a force hammer or vibrator, and a power amplifier.

[0003] In related technologies, the measurement of natural frequencies for shaft products includes CAE analysis using software dynamics analysis methods and natural frequency testing using the impact test method. CAE analysis using software dynamics analysis methods requires relevant analysis software, CAE engineers, and the establishment of simulation models. Although the structure of shaft products themselves is not complex, actual measurements require incorporating vehicle-wide influencing factors into the working environment, resulting in a large workload for simulation analysis and consequently low analysis efficiency. On the other hand, the impact test method requires a large amount of testing equipment, including data acquisition, sensors, cables, impact hammers, and software, which is time-consuming and labor-intensive, failing to meet the demands of the rapidly evolving automotive industry. Furthermore, manual operation introduces relatively more errors and interference factors, leading to relatively poor measurement accuracy and low testing efficiency. The most common problems with the impact test method are repeated impacts and false triggering, both of which negatively impact testing efficiency. Summary of the Invention

[0004] In response to the problems of high cost, long time consumption, large experimental errors, and low efficiency in the relevant technologies for measuring and analyzing the natural frequency of shaft products.

[0005] In a first aspect, embodiments of this application provide a natural frequency tester, which includes:

[0006] A clamping assembly used to clamp the test piece;

[0007] At least one signal generator is disposed on the fixture assembly, the signal generator being used to apply vibration excitation to the test piece in a preset manner;

[0008] At least one vibration sensor is disposed on the fixture assembly, the vibration sensor being used to acquire the excitation signal of the test piece;

[0009] The detection and control chamber is connected to the vibration sensor signal and is used to calculate the natural frequency value of the test piece based on the excitation signal.

[0010] In conjunction with the first aspect, in one embodiment, the clamp assembly includes:

[0011] Two clips, one of which contains the detection and control compartment;

[0012] A drive unit is movably connected to the two clamping plates, which can drive the two clamping plates to rotate to clamp or release the test piece.

[0013] In conjunction with the first aspect, in one embodiment, the drive unit includes: a movable shaft disposed between and connected to the two clamps.

[0014] In conjunction with the first aspect, in one embodiment, photoelectric sensors are provided in the two clamps, and the photoelectric sensors are connected to the signal line of the detection and control chamber. The photoelectric sensors are used to detect the size information of the test piece.

[0015] The detection control chamber is signal-connected to the drive unit. The detection control chamber can control the drive unit to adjust the size of the clamping openings of the two clamping plates according to the size information of the test piece, so as to clamp the test piece.

[0016] In conjunction with the first aspect, in one embodiment, the signal generator and the vibration sensor are respectively provided on the two clamping plates, and when the two clamping plates clamp the test piece, the signal generator and the vibration sensor are in contact with the test piece.

[0017] In conjunction with the first aspect, in one embodiment, five signal generators and five vibration sensors are respectively provided on the two clips.

[0018] In conjunction with the first aspect, in one embodiment, the fixture assembly has a digital display control screen on its surface. The digital display control screen is connected to the detection control chamber and the signal generator. The digital display control screen is used to drive the signal generator to apply vibration excitation to the test piece in a preset manner.

[0019] Secondly, embodiments of this application provide a method for testing the intrinsic frequency using the aforementioned intrinsic frequency tester, comprising:

[0020] Turn on the control switch to clamp the fixture assembly onto the test piece;

[0021] Vibration excitation is applied to the test piece using a signal generator;

[0022] The excitation signal collected by the vibration sensor is transmitted to the detection and control chamber, which processes the excitation signal and outputs the natural frequency value.

[0023] In conjunction with the second aspect, in one embodiment, opening the control switch to clamp the fixture assembly onto the test piece includes:

[0024] The fixture assembly is pre-clamped onto the test piece;

[0025] When the control switch is turned on, the photoelectric sensor on the fixture assembly detects the dimensions of the test piece.

[0026] The detection control chamber adjusts the clamping opening size of the two clamping plates according to the detection results of the photoelectric sensor to clamp the test piece and make the signal generator and the vibration sensor contact the test piece.

[0027] In conjunction with the second aspect, in one embodiment, the detection and control chamber processes the excitation signal, including:

[0028] The detection and control chamber is used to perform a fast Fourier transform on the excitation signal and read the frequency peak as the inherent frequency value.

[0029] The beneficial effects of the technical solutions provided in this application include at least the following:

[0030] This application incorporates a controllable signal generator on the fixture, allowing operators to automatically control the vibration excitation of the test piece via a switch, thus avoiding errors inherent in manual hammering. Furthermore, the testing instrument itself includes an analyzer for rapid data processing. This enables rapid measurement of the natural frequency, improving measurement efficiency. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the inherent frequency tester in the embodiments of this application;

[0033] Figure 2 This is a cross-sectional view of the inherent frequency tester in the embodiments of this application.

[0034] In the figure: 1. Fixture assembly; 11. Clamping plate; 12. Drive unit; 2. Test piece; 3. Signal generator; 4. Vibration sensor; 5. Detection and control chamber; 6. Digital display control screen; 7. Battery; 8. Charging port; 9. Photoelectric sensor. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0036] In response to the problems of high cost, long time consumption, large experimental errors, and low efficiency in the relevant technologies for measuring and analyzing the natural frequency of shaft products.

[0037] Firstly, such as Figure 1 As shown, this application provides a natural frequency tester, which includes: a fixture assembly 1, at least one signal generator 3, at least one vibration sensor 4, and a detection and control chamber 5; wherein,

[0038] A clamping assembly 1 is used to clamp the test piece 2. A signal generator 3 is disposed on the clamping assembly 1, and the signal generator 3 is used to apply vibration excitation to the test piece 2 in a preset manner. A vibration sensor 4 is disposed on the clamping assembly 1, and the vibration sensor 4 is used to collect the excitation signal of the test piece 2. A detection control chamber 5 is signal-connected to the vibration sensor 4, and the detection control chamber 5 is used to calculate the natural frequency value of the test piece 2 based on the excitation signal. The signal generator 3 in this application can be a vibration generator.

[0039] It is worth noting that traditional hammer-based measurements, requiring manual release of the hammer, are prone to repeated strikes and accidental triggering, resulting in significant measurement errors. Simulation analysis for natural frequency measurement necessitates modeling and setting parameters for the test piece 2. Since the influence of the entire vehicle must be considered during testing, simulation analysis requires incorporating complex influencing factors, leading to a substantial workload. This application addresses this by installing a controllable signal generator 3 on the fixture assembly 1, allowing operators to automatically control the vibration excitation of the test piece via a switch, avoiding errors inherent in manual hammering. Furthermore, the testing instrument in this application includes a detection control chamber 5 for rapid data processing. This enables rapid measurement of natural frequencies, improving measurement efficiency.

[0040] In some preferred embodiments, the clamp assembly 1 includes: two clamping plates 11 and a driving unit 12; wherein,

[0041] Two clamping plates 11, one of which has the detection control chamber 5 inside; a driving unit 12, which is movably connected to the two clamping plates 11, the driving unit 12 can drive the two clamping plates 11 to rotate to clamp or release the test piece 2.

[0042] Understandably, due to their special shape, conventional testing instruments are difficult to fix onto shaft-shaped test pieces 2, and cannot stably provide vibration excitation. This application uses two clamping plates 11 to clamp and fix the test piece 2, which works well for shaft-shaped test pieces 2. Operators can flexibly and quickly fix the testing instrument onto the shaft-shaped test piece 2, making it more convenient to use and saving testing time.

[0043] Furthermore, the drive unit 12 includes a movable shaft disposed between the two clamping pieces 11 and connected to the two clamping pieces 11.

[0044] Understandably, the movable shaft is connected to the detection control chamber 5 via a signal. The detection control chamber 5 can drive the movable shaft to rotate, thereby adjusting the opening of the two clamping plates 11 to clamp or release the test piece 2. When the two clamping plates 11 clamp the test piece 2, both the signal generator 3 and the vibration sensor 4 are in contact with the test piece 2 to ensure the stability of vibration excitation application and information collection.

[0045] In some preferred embodiments, such as Figure 2 As shown, photoelectric sensors 9 are provided in the two clamping pieces 11. The photoelectric sensors 9 are connected to the signal line of the detection and control chamber 5. The photoelectric sensors 9 are used to detect the size information of the test piece 2.

[0046] The detection control chamber 5 is connected to the drive unit 12 by signal. The detection control chamber 5 can control the drive unit 12 to adjust the size of the clamping opening of the two clamping plates 11 according to the size information of the test piece 2, so as to clamp the test piece 2.

[0047] As can be understood, as mentioned above, for some shaft-type test pieces 2, fixing the testing instrument and maintaining its stable position during the testing process is a crucial step. This application utilizes a photoelectric sensor 9 to detect the diameter of the test piece 2, and then transmits it to the detection control chamber 5. The detection control chamber 5 automatically adjusts the clamping size of the fixture assembly 1 to automatically clamp the test piece 2, thereby ensuring that samples of different diameters can be clamped.

[0048] Furthermore, such as Figure 2As shown, the signal generator 3 and the vibration sensor 4 are respectively provided on the two clamping plates 11, and when the two clamping plates 11 clamp the test piece 2, the signal generator 3 and the vibration sensor 4 are in contact with the test piece 2.

[0049] In some preferred embodiments, five signal generators 3 and five vibration sensors 4 are respectively provided on the two clips 11.

[0050] Understandably, to avoid unexpected situations such as signal generator 3 malfunction, this application provides five signal generators 3 to ensure that vibration excitation is applied to the test piece 2. Furthermore, this application also includes five vibration sensors 4 to ensure that the excitation signal from the test piece 2 is collected.

[0051] Furthermore, the five signal generators 3 and the five vibration sensors 4 are evenly spaced on their respective clips 11.

[0052] In some alternative embodiments, such as Figure 2 As shown, in order to improve the stability of excitation application and signal acquisition, the five signal generators 3 and the five vibration sensors 4 are uniformly arranged radially along the test piece 2.

[0053] In some optional embodiments, the surface of the fixture assembly 1 is provided with a digital display control screen 6, which is connected to the detection control chamber 5 and the signal generator 3. The digital display control screen 6 is used to drive the signal generator 3 to apply vibration excitation to the test piece 2 in a preset manner.

[0054] Preferably, the digital display control panel 6 is equipped with a control switch, which the operator can manually trigger to automatically clamp the fixture assembly 1 and begin the natural frequency testing process. Furthermore, the digital display control panel 6 can also display the measured natural frequency value on the screen, allowing the operator to quickly receive the test information.

[0055] Furthermore, the fixture assembly 1 is equipped with a battery 7 and a corresponding charging port 8, which serve as the power source for the fixture assembly 1, the signal generator 3, the vibration sensor 4, the detection control chamber 5, and the digital display control screen 6.

[0056] In some alternative embodiments, the fixture assembly 1 is made of a lightweight, low-damping material to avoid the influence of the sample's natural frequency on the mass and damping of the tester itself.

[0057] In some preferred embodiments, the detection control chamber 5 is used to perform FFT (Fast Fourier Transform) analysis on the excitation signal collected by the vibration sensor 4, and finally read the frequency peak value and display it on the digital display control screen 6.

[0058] In this embodiment, when the natural frequency tester is used, it is first initially clamped onto the test piece 2. After pressing the power button, the photoelectric sensor 9 is the first to sense the test piece 2. The photoelectric sensor 9 measures the diameter d of the test piece 2 and transmits the data back to the detection control chamber 5. The detection control chamber 5 outputs a command to automatically adjust the opening size D (D≈d+2mm) of the clamping assembly 1 to ensure that the clamping assembly 1 can clamp the test piece and that the signal generator 3, vibration sensor 4, and test piece 2 can make contact. At this time, clicking the "Start Test" button on the digital display control screen 6 will cause the signal generator 3 to send a random signal F to the test piece 2. The vibration sensor 4 can collect the acceleration signal a. The data collection and processing module in the detection control chamber 5 will perform a Fourier transform on the ratio of the acceleration signal a to the excitation force signal F to obtain the frequency domain transfer function H as follows:

[0059] H = aa / F = 2πf / F

[0060] Furthermore, the average value is calculated after the signal is excited 5 times in each test, and the above test process is repeated 3 times to maintain data consistency before displaying it on the digital display control screen 6.

[0061] It should be noted that, in one embodiment of this application, five signal generators 3 and five vibration sensors 4 are included, enabling a multiple-input multiple-output (MIMO) method (antenna system). The five vibration generators can excite the sample in three different directions (X, Y, Z), thus obtaining a complete multi-column frequency response function matrix. The five fixed vibration sensors 4, acting as a response, can obtain multiple rows of the frequency response function matrix, maximizing the extraction of all natural frequencies of interest. The measured transfer function matrix is ​​shown below:

[0062]

[0063] Secondly, this application provides an automotive component testing system, which includes a natural frequency tester. The natural frequency tester includes: a fixture assembly 1, at least one signal generator 3, at least one vibration sensor 4, and a detection control chamber 5; wherein...

[0064] A clamping assembly 1 is used to clamp the test piece 2. A signal generator 3 is disposed on the clamping assembly 1, and the signal generator 3 is used to apply vibration excitation to the test piece 2 in a preset manner. A vibration sensor 4 is disposed on the clamping assembly 1, and the vibration sensor 4 is used to collect the excitation signal of the test piece 2. A detection control chamber 5 is signal-connected to the vibration sensor 4, and the detection control chamber 5 is used to calculate the natural frequency value of the test piece 2 based on the excitation signal. In this application, the signal generator 3 is a vibration generator.

[0065] It is worth noting that traditional hammer-based measurements, requiring manual release of the hammer, are prone to repeated strikes and accidental triggering, resulting in significant measurement errors. Simulation analysis for natural frequency measurement necessitates modeling and setting parameters for the test piece 2. Since the influence of the entire vehicle must be considered during testing, simulation analysis requires incorporating complex influencing factors, leading to a substantial workload. This application addresses this by installing a controllable signal generator 3 on the fixture assembly 1, allowing operators to automatically control the vibration excitation of the test piece via a switch, avoiding errors inherent in manual hammering. Furthermore, the testing instrument in this application includes a detection control chamber 5 for rapid data processing. This enables rapid measurement of natural frequencies, improving measurement efficiency.

[0066] In some preferred embodiments, the clamp assembly 1 includes: two clamping plates 11 and a driving unit 12; wherein,

[0067] Two clamping plates 11, one of which has the detection control chamber 5 inside; a driving unit 12, which is movably connected to the two clamping plates 11, the driving unit 12 can drive the two clamping plates 11 to rotate to clamp or release the test piece 2.

[0068] Understandably, due to their special shape, conventional testing instruments are difficult to fix onto shaft-shaped test pieces 2, and cannot stably provide vibration excitation. This application uses two clamping plates 11 to clamp and fix the test piece 2, which works well for shaft-shaped test pieces 2. Operators can flexibly and quickly fix the testing instrument onto the shaft-shaped test piece 2, making it more convenient to use and saving testing time.

[0069] Furthermore, the drive unit 12 includes a movable shaft disposed between the two clamping pieces 11 and connected to the two clamping pieces 11.

[0070] Understandably, the movable shaft is connected to the detection control chamber 5 via a signal. The detection control chamber 5 can drive the movable shaft to rotate, thereby adjusting the opening of the two clamping plates 11 to clamp or release the test piece 2. When the two clamping plates 11 clamp the test piece 2, both the signal generator 3 and the vibration sensor 4 are in contact with the test piece 2 to ensure the stability of vibration excitation application and information collection.

[0071] In some preferred embodiments, such as Figure 2 As shown, photoelectric sensors 9 are provided in the two clamping pieces 11. The photoelectric sensors 9 are connected to the signal line of the detection and control chamber 5. The photoelectric sensors 9 are used to detect the size information of the test piece 2.

[0072] The detection control chamber 5 is connected to the drive unit 12 by signal. The detection control chamber 5 can control the drive unit 12 to adjust the size of the clamping opening of the two clamping plates 11 according to the size information of the test piece 2, so as to clamp the test piece 2.

[0073] As can be understood, as mentioned above, for some shaft-type test pieces 2, fixing the testing instrument and maintaining its stable position during the testing process is a crucial step. This application utilizes a photoelectric sensor 9 to detect the diameter of the test piece 2, and then transmits it to the detection control chamber 5. The detection control chamber 5 automatically adjusts the clamping size of the fixture assembly 1 to automatically clamp the test piece 2, thereby ensuring that samples of different diameters can be clamped.

[0074] Furthermore, such as Figure 2 As shown, the signal generator 3 and the vibration sensor 4 are respectively provided on the two clamping plates 11, and when the two clamping plates 11 clamp the test piece 2, the signal generator 3 and the vibration sensor 4 are in contact with the test piece 2.

[0075] In some preferred embodiments, five signal generators 3 and five vibration sensors 4 are respectively provided on the two clips 11.

[0076] Understandably, to avoid unexpected situations such as signal generator 3 malfunction, this application provides five signal generators 3 to ensure that vibration excitation is applied to the test piece 2. Furthermore, this application also includes five vibration sensors 4 to ensure that the excitation signal from the test piece 2 is collected.

[0077] Furthermore, the five signal generators 3 and the five vibration sensors 4 are evenly spaced on their respective clips 11.

[0078] In some alternative embodiments, such as Figure 2As shown, in order to improve the stability of excitation application and signal acquisition, the five signal generators 3 and the five vibration sensors 4 are uniformly arranged radially along the test piece 2.

[0079] In some optional embodiments, the surface of the fixture assembly 1 is provided with a digital display control screen 6, which is connected to the detection control chamber 5 and the signal generator 3. The digital display control screen 6 is used to drive the signal generator 3 to apply vibration excitation to the test piece 2 in a preset manner.

[0080] Preferably, the digital display control panel 6 is equipped with a control switch, which the operator can manually trigger to automatically clamp the fixture assembly 1 and begin the natural frequency testing process. Furthermore, the digital display control panel 6 can also display the measured natural frequency value on the screen, allowing the operator to quickly receive the test information.

[0081] Furthermore, the fixture assembly 1 is equipped with a battery 7 and a corresponding charging port 8, which serve as the power source for the fixture assembly 1, the signal generator 3, the vibration sensor 4, the detection control chamber 5, and the digital display control screen 6.

[0082] In some alternative embodiments, the fixture assembly 1 is made of a lightweight, low-damping material to avoid the influence of the sample's natural frequency on the mass and damping of the tester itself.

[0083] In some preferred embodiments, the detection control chamber 5 is used to perform FFT (Fast Fourier Transform) analysis on the excitation signal collected by the vibration sensor 4, and finally read the frequency peak value and display it on the digital display control screen 6.

[0084] In this embodiment, when the natural frequency tester is used, it is first initially clamped onto the test piece 2. After pressing the power button, the photoelectric sensor 9 is the first to sense the test piece 2. The photoelectric sensor 9 measures the diameter d of the test piece 2 and transmits the data back to the detection control chamber 5. The detection control chamber 5 outputs a command to automatically adjust the opening size D (D≈d+2mm) of the clamping assembly 1 to ensure that the clamping assembly 1 can clamp the test piece and that the signal generator 3, vibration sensor 4, and test piece 2 can make contact. At this time, clicking the "Start Test" button on the digital display control screen 6 will cause the signal generator 3 to send a random signal F to the test piece 2. The vibration sensor 4 can collect the acceleration signal a. The data collection and processing module in the detection control chamber 5 will perform a Fourier transform on the ratio of the acceleration signal a to the excitation force signal F to obtain the frequency domain transfer function H as follows:

[0085] H = a / F = 2πf / F

[0086] Furthermore, the average value is calculated after the signal is excited 5 times in each test, and the above test process is repeated 3 times to maintain data consistency before displaying it on the digital display control screen 6.

[0087] Thirdly, this application provides a method for testing the natural frequency using the aforementioned natural frequency tester, which includes the following steps:

[0088] Step S1: Turn on the control switch to clamp the fixture assembly 1 onto the test piece 2.

[0089] Specifically, step S1 includes: pre-clamping the fixture assembly 1 onto the test piece 2. Then, turning on the control switch, the photoelectric sensor 9 on the fixture assembly 1 detects the dimensions of the test piece 2.

[0090] Furthermore, the detection control chamber 5 adjusts the clamping opening size of the two clamping plates 11 according to the detection result of the photoelectric sensor 9 to clamp the test piece 2 and make the signal generator 3 and the vibration sensor 4 contact the test piece 2.

[0091] Understandably, the above process solved the problem of the tester not being securely installed with the test piece 2, and also greatly simplified the manual operation and improved work efficiency.

[0092] Step S2: Apply vibration excitation to the test piece 2 through the signal generator 3;

[0093] Specifically, the signal generator sends a random signal F to the test piece, and the vibration sensor can collect the acceleration signal a.

[0094] Step S3: The excitation signal collected by the vibration sensor 4 is transmitted to the detection and control chamber 5, which processes the excitation signal and outputs the natural frequency value.

[0095] Specifically, step S3 includes: performing a Fast Fourier Transform on the excitation signal using the detection and control chamber 5, and reading the frequency peak value as the inherent frequency value. The signal is excited 5 times each time, and the average is calculated. The experiment is repeated three times to maintain data consistency.

[0096] In summary, this application, by incorporating a controllable signal generator on the clamping device, allows operators to automatically control the vibration excitation of the test piece via a switch, avoiding errors inherent in manual hammering. Furthermore, the testing instrument itself includes an analyzer for rapid data processing, enabling rapid measurement of the natural frequency and improving measurement efficiency. The instrument features a display screen and a switch, allowing direct viewing of the natural frequency value. Additionally, the clamps are equipped with a photoelectric sensor capable of detecting the diameter of the test piece and automatically adjusting the clamp size.

[0097] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0098] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0099] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A natural frequency tester, characterized in that, include: A clamping assembly (1) is used to clamp the test piece (2); At least one signal generator (3) is disposed on the fixture assembly (1), the signal generator (3) being used to apply vibration excitation to the test piece (2) in a preset manner; At least one vibration sensor (4) is disposed on the fixture assembly (1), the vibration sensor (4) being used to acquire the excitation signal of the test piece (2); The detection control chamber (5) is connected to the vibration sensor (4) and is used to calculate the natural frequency value of the test piece (2) based on the excitation signal. The fixture assembly (1) includes two clamping plates (11) and a drive unit (12), wherein the detection control chamber (5) is provided in one of the clamping plates (11); the drive unit (12) is movably connected to the two clamping plates (11), and the drive unit (12) can drive the two clamping plates (11) to rotate to clamp or release the test piece (2). The drive unit (12) includes: a movable shaft, which is disposed between the two clamps (11) and connected to the two clamps (11); The two clips (11) are equipped with photoelectric sensors (9), which are connected to the signal line of the detection control chamber (5). The photoelectric sensors (9) are used to detect the size information of the test piece (2). The detection control chamber (5) is connected to the drive unit (12) by signal. The detection control chamber (5) can control the drive unit (12) to adjust the size of the clamping opening of the two clamping plates (11) according to the size information of the test piece (2) to clamp the test piece (2). The two clamping plates (11) are respectively provided with the signal generator (3) and the vibration sensor (4). When the two clamping plates (11) clamp the test piece (2), the signal generator (3) and the vibration sensor (4) are in contact with the test piece (2).

2. The natural frequency tester as described in claim 1, characterized in that: Five signal generators (3) and five vibration sensors (4) are respectively provided on the two clips (11).

3. The natural frequency tester as described in claim 1, characterized in that: The fixture assembly (1) is provided with a digital display control screen (6) on its surface. The digital display control screen (6) is connected to the detection control chamber (5) and the signal generator (3). The digital display control screen (6) is used to drive the signal generator (3) to apply vibration excitation to the test piece (2) in a preset manner.

4. A method for testing the natural frequency using the natural frequency tester as described in claim 1, characterized in that, include: Turn on the control switch to clamp the fixture assembly (1) onto the test piece (2); Vibration excitation is applied to the test piece (2) by a signal generator (3); The excitation signal collected by the vibration sensor (4) is sent to the detection and control chamber (5), which processes the excitation signal and outputs the natural frequency value.

5. The natural frequency testing method as described in claim 4, characterized in that, The opening of the control switch to clamp the fixture assembly (1) onto the test piece (2) includes: The clamp assembly (1) is pre-clamped onto the test piece (2); When the control switch is turned on, the photoelectric sensor (9) on the fixture assembly (1) detects the size of the test piece (2); The detection control chamber (5) adjusts the clamping opening size of the two clamping plates (11) according to the detection result of the photoelectric sensor (9) to clamp the test piece (2) and make the signal generator (3) and the vibration sensor (4) contact the test piece (2).

6. The natural frequency testing method as described in claim 4, characterized in that, The detection and control chamber (5) processes the excitation signal, including: The detection control chamber (5) is used to perform a fast Fourier transform on the excitation signal and the frequency peak value is read as the inherent frequency value.

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