Membrane vibration displacement measuring device based on sound wave excitation

Abstract

The utility model belongs to the technical field of instruments and meters, and provides a film vibration displacement measuring device based on sound wave excitation, and the device comprises a supporting platform. The optical lifting platform is fixed on the supporting platform, and the optical lifting platform comprises an adjusting knob and scale marks; the displacement sensing piece is mounted on the optical lifting table so as to adjust the height of the displacement sensing piece through the adjusting knob; the sound excitation structure is arranged on the supporting platform and is opposite to the displacement induction part, the sound excitation structure comprises a loudspeaker, a sound insulation cover and a hollow body, the loudspeaker is located in the sound insulation cover, and an opening is formed in the side, facing the displacement induction part, of the sound insulation cover. Through the arrangement of the acoustic shield and the hollow body, the non-contact acoustic excitation of the measured film is realized, the non-contact measurement of the measured film is realized through arranging the displacement sensing piece above the measured film, the influence of external factors on the dynamic characteristics of the measured film is reduced, and the measurement accuracy of the measured film is improved. Therefore, the displacement output amplitudes of the measured film under different frequencies can be accurately obtained.

Description

Technical Field

[0001] The present application relates to the technical field of instruments and meters, and in particular to a film vibration displacement measuring device based on acoustic wave excitation. Background Art

[0002] Vibration signals are of great reference value in characterizing the dynamic characteristics of devices, especially for small-sized thin-film devices, which are light in weight and easily affected by factors such as the additional mass generated by the test device and sensor, and have difficulties in measuring due to small vibration amplitude. In addition, due to the instability of external environmental factors, the dynamic characteristics of small-sized thin films are also easily affected, making it difficult to obtain the amplitude of their displacement output under different frequency excitations. Utility Model Content

[0003] The embodiment of the present application provides a film vibration displacement measurement device based on acoustic wave excitation, which reduces the influence of external factors on the dynamic characteristics of the film being measured, and through the design of a non-contact excitation and detection device, accurately obtains the amplitude of the displacement output of the film being measured at different frequencies to characterize its dynamic characteristics.

[0004] The embodiment of the present application provides a film vibration displacement measurement device based on acoustic wave excitation, comprising:

[0005] Support platform;

[0006] An optical lifting platform, fixed on the supporting platform, the optical lifting platform comprising an adjustment knob and a scale mark;

[0007] A displacement sensing component is installed on the optical lifting platform so that the height of the displacement sensing component can be adjusted by the adjusting knob;

[0008] An acoustic excitation structure is arranged on the supporting platform and opposite to the displacement sensing element, the acoustic excitation structure comprises a speaker, a soundproof cover and a hollow body, the speaker is located in the soundproof cover, and the soundproof cover has an opening on a side facing the displacement sensing element;

[0009] The hollow body extends in a vertical direction, and the bottom end of the hollow body is arranged at the opening of the sound insulation enclosure. The top end of the hollow body has an opening, and the opening is connected to the inner cavity of the sound insulation enclosure. The hollow body is configured to carry the film to be measured and transmit acoustic excitation energy to the film to be measured.

[0010] In a feasible implementation, the hollow body has a hollow area, and the diameter of the hollow area is greater than or equal to the diameter of the opening;

[0011] The diameter of the opening is adapted to the size of the film to be measured.

[0012] In a feasible implementation, the hollow body includes a first cylinder and a second cylinder, the bottom end of the first cylinder is fixed to the opening of the sound insulation cover, the second cylinder is detachably connected to the top of the first cylinder, and the opening is formed on a side of the second cylinder facing away from the first cylinder.

[0013] In a feasible implementation, the first cylinder is columnar, and the top of the first cylinder is configured with an external thread;

[0014] The second cylinder is in the shape of a granary, and the bottom of the second cylinder is configured with an internal thread for threaded connection with the first cylinder. The top surface of the second cylinder is annular in the vertical direction, so that the film to be tested can be fixed on the top surface of the second cylinder.

[0015] In a feasible implementation, the film to be tested is bonded to the top surface of the second cylinder by adhesive.

[0016] The displacement sensing component is a laser displacement sensor, and the center of the film to be measured is used to reflect the laser emitted by the laser displacement sensor.

[0017] In a feasible implementation, the film vibration displacement measuring device further includes an optical plate and an adapter plate fixedly connected in sequence along a horizontal direction, one end of the optical plate is fixed to the optical lifting platform, and the adapter plate is used to fix the displacement sensing component.

[0018] In a feasible implementation, the speaker is embedded in a sound box, and the sound box is arranged in the sound insulation cover;

[0019] The shape of the sound insulation cover is adapted to the shape of the sound box.

[0020] In a feasible implementation, the film vibration displacement measuring device further includes:

[0021] A signal generator, disposed on the supporting platform, for generating an excitation signal of a specific frequency;

[0022] The power amplifier is arranged on the supporting platform and is electrically connected to the signal generator and the speaker respectively.

[0023] In a feasible implementation, the film vibration displacement measuring device further includes:

[0024] A controller, electrically connected to the displacement sensing element, to convert the optical signal of the displacement sensing element into an analog signal;

[0025] A data acquisition card is electrically connected to the controller, and is used to acquire the analog signal and perform analog-to-digital conversion so as to transmit the analog signal to a computer for analysis and display.

[0026] The film vibration displacement measuring device based on acoustic wave excitation provided in the embodiment of the present application can reduce the influence of the external environment by arranging the optical lifting platform, the displacement sensing component and the acoustic excitation structure on a support platform with an anti-vibration function, and realizes non-contact acoustic excitation of the measured film through the arrangement of the sound insulation cover and the hollow body. By arranging the displacement sensing component above the measured film, non-contact measurement of the measured film can be realized. This arrangement can further reduce the influence of external factors on the dynamic characteristics of the measured film, thereby accurately obtaining the amplitude of the displacement output of the measured film under acoustic wave excitation of different frequencies. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 is a schematic diagram of the overall structure of a film vibration displacement measuring device provided in an embodiment of the present application;

[0029] Figure 2 is a schematic diagram of the structure of an incentive structure provided according to an embodiment of the present application;

[0030] Figure 3 is a schematic structural diagram of the top surface of the second cylinder provided according to an embodiment of the present application;

[0031] Figure 4 is a schematic diagram of the three-dimensional structure of a first cylinder provided according to an embodiment of the present application;

[0032] Figure 5 is a front view structural schematic diagram of a first cylinder provided according to an embodiment of the present application;

[0033] Figure 6 is a schematic diagram of a top view of the structure of a first cylinder provided according to an embodiment of the present application;

[0034] Figure 7 is a front view structural schematic diagram of a second cylinder provided according to an embodiment of the present application;

[0035] Figure 8 is a schematic diagram of a top view of the structure of a second cylinder provided according to an embodiment of the present application;

[0036] Fig. 9 is a schematic diagram of the three-dimensional structure of the second cylinder provided according to an embodiment of the present application;

[0037] Fig.10 is a measurement flow chart of a film vibration displacement measurement device provided in an embodiment of the present application;

[0038] Fig.11 It is a time domain signal diagram obtained by measuring the film vibration displacement measurement device provided by an embodiment of the present application;

[0039] Fig.12 is a power spectrum curve diagram obtained by measuring the film vibration displacement measurement device provided in one embodiment of the present application;

[0040] Fig.13 This is a time domain signal diagram obtained by measuring the film vibration displacement measurement device provided by another embodiment of the present application.

[0041] Fig.14 It is a power spectrum curve diagram obtained by measuring a film vibration displacement measurement device provided in another embodiment of the present application.

[0042] Reference numerals:

[0043] 100. Support platform;

[0044] 200, optical lifting platform; 210, adjustment knob;

[0045] 300, displacement sensing parts;

[0046] 400, acoustic excitation structure; 430, speaker; 410, sound insulation cover; 420, hollow body; 421, first cylinder; 4211, external thread; 422, second cylinder; 4221, opening; 4222, internal thread;

[0047] 500, signal generator;

[0048] 600, power amplifier;

[0049] 700, optical flat plate;

[0050] 800, adapter board. DETAILED DESCRIPTION

[0051] The following is a further detailed description of the implementation of the present application in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present application but cannot be used to limit the scope of the present application.

[0052] In the description of the embodiments of the present application, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0053] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0054] In the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0055] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0056] Vibration signals are of great reference value in characterizing the dynamic characteristics of devices, especially for small-sized thin-film devices, which have the following difficulties: light weight, easy influence of the additional mass generated by the test equipment and sensors on their own dynamic characteristics, small vibration amplitude and difficulty in measurement. The existence of external factors can easily affect the dynamic characteristics of small-sized thin films, making it difficult to obtain the amplitude of their displacement output at different frequencies.

[0057] In view of the above problems, the present invention provides a device for measuring the vibration displacement of a thin film based on acoustic wave excitation, and in particular, provides a reliable device for measuring the vibration displacement of a small-aperture thin film. Figure 1 is a schematic diagram of the overall structure of a film vibration displacement measuring device provided in an embodiment of the present application, such as Figure 1 As shown, the film vibration displacement measuring device may include a supporting platform 100 , an optical lifting platform 200 , a displacement sensing element 300 and an acoustic excitation structure 400 .

[0058] The optical lifting platform 200 is fixed on the supporting platform 100, and the optical lifting platform 200 includes an adjusting knob 210 and a scale mark; the displacement sensing member 300 is installed on the optical lifting platform 200, so that the height of the displacement sensing member 300 can be adjusted by adjusting the knob 210; the acoustic excitation structure 400 is arranged on the supporting platform 100 and is arranged opposite to the displacement sensing member 300, and the acoustic excitation structure includes a speaker 430, a sound insulation cover 410 and a hollow body 420, the speaker 430 is located in the sound insulation cover 410, and the sound insulation cover 410 has an opening on a side facing the displacement sensing member 300; wherein the hollow body 420 extends in a vertical direction, and the bottom end of the hollow body 420 is arranged at the opening of the sound insulation cover 410, and the top end of the hollow body 420 has an opening 4221, and the opening 4221 is connected to the inner cavity of the sound insulation cover 410, and the hollow body 420 is configured to carry the film to be measured and transmit the acoustic excitation energy to the film to be measured.

[0059] The support platform 100 may be a three-layer sandwich honeycomb structure. The support platform 100 of this structure has good anti-vibration function. Placing the optical lifting platform 200, the displacement sensing element 300 and the acoustic excitation structure 400 on the support platform 100 can effectively isolate vibration, thereby reducing the impact of the external environment on the measuring device.

[0060] The optical lifting platform 200 arranged on the supporting platform 100 can drive the displacement sensing component 300 to be precisely lifted and lowered in a direction perpendicular to the surface of the supporting platform 100. Specifically, the displacement sensing component 300 can be precisely moved by manually turning the adjustment knob 210 and combining the scale markings on the side wall of the optical lifting platform 200 (similar to a vernier caliper) to ensure that the displacement sensing component 300 installed on the optical lifting platform 200 works within a specified measurement range. In other words, it is necessary to ensure that the distance between the displacement sensing component 300 and the film being measured is optimal.

[0061] The acoustic excitation structure 400 is disposed as a whole on the table surface of the supporting platform 100. To facilitate the description of the structure of the acoustic excitation structure 400, the acoustic excitation structure 400 is divided into a soundproof enclosure 410 and a hollow body 420. A speaker 430 for emitting sound waves is disposed in the soundproof enclosure 410. To facilitate the transmission of sound waves from the soundproof enclosure 410 to the top of the hollow body 420, an opening is configured on one side (top) of the soundproof enclosure 410 facing the displacement sensing element 300. When the sound waves are transmitted from the opening to the outside through sound insulation, in order to achieve the continued transmission of the sound waves and attenuate the evanescent waves, a hollow body 420 is disposed at the opening, and the hollow body 420 is connected to the inner cavity of the soundproof enclosure 410. In order to directly transmit the sound waves to the film to be measured, an opening 4221 is also configured on the top of the hollow body 420 to communicate with the inner hollow area of ​​the hollow body 420, that is, the opening 4221 is directly connected to the inner cavity of the soundproof enclosure 410. Since the hollow body 420 extends in the vertical direction and has a certain length, it can achieve effective transmission of acoustic energy while also being able to attenuate evanescent waves.

[0062] In one example, the displacement sensing element 300 may be a laser displacement sensor, which can achieve displacement measurement through triangulation. The specific working principle can be understood by referring to the relevant technology, and will not be described in detail here.

[0063] When measuring, the film vibration displacement measuring device of this example firstly sticks the film to be measured to the upper end surface of the hollow body 420, and adjusts the optical lifting platform 200 so that the emission light spot of the laser displacement sensor hits the center of the film to be measured, that is, the distance between the film to be measured and the laser displacement sensor is kept within the effective measurement distance. Then the speaker 430 is stimulated to emit acoustic energy, and the acoustic energy travels along the opening of the soundproof cover 410 and the hollow area of ​​the hollow body 420 until it reaches the film to be measured at the opening 4221, thereby achieving acoustic excitation of the film to be measured. In this process, the laser displacement sensor can perform non-contact measurement of the vibration displacement of the film to be measured, and collect and process the data through the controller, etc., so as to display the vibration amplitude of the film to be measured.

[0064] In the present application, by arranging the optical lifting platform 200, the displacement sensing element 300 and the acoustic excitation structure 400 on the support platform 100 with an anti-vibration function, the influence of the external environment can be reduced, and by arranging the sound insulation cover 410 and the hollow body 420, non-contact acoustic excitation of the measured film can be achieved. By arranging the displacement sensing element 300 above the measured film, non-contact measurement of the measured film can be achieved. This arrangement can further reduce the influence of external factors on the dynamic characteristics of the measured film, thereby accurately obtaining the amplitude of the displacement output of the measured film at different frequencies.

[0065] Next, we will combine the attached Figure 1 -Attached Fig.14 The detailed structure of the film vibration displacement measuring device based on acoustic wave excitation provided in an embodiment of the present application is described.

[0066] like Figure 2 , Figure 3 and Fig. 9 As shown, in some embodiments, the hollow body 420 has a hollow area, and the diameter of the hollow area is greater than or equal to the diameter of the opening 4221; the diameter of the opening 4221 is adapted to the size of the film to be measured.

[0067] It is understandable that in order to achieve effective transmission of acoustic energy in the hollow area of ​​the hollow body 420, the diameter of the hollow area can be increased appropriately, but since the smaller film to be tested needs to be set on the upper end surface of the hollow body 420, the upper end surface of the hollow body 420 cannot be too large, and the opening 4221 of the upper end surface needs to be adapted to the size of the film to be tested. At the same time, considering the manufacturing feasibility, the diameter of the hollow area can be made larger than the diameter of the opening 4221.

[0068] In some examples, the small-pore membrane may be defined as a membrane with a diameter less than 50 mm. Then the diameter of the opening 4221 may be slightly smaller than the diameter of the membrane, so that the edge of the membrane can be fixed on the upper end surface of the hollow body 420 .

[0069] like Figure 3-Figure 9 As shown, in some embodiments, the hollow body 420 includes a first cylinder 421 and a second cylinder 422, the bottom end of the first cylinder 421 is fixed to the opening of the sound insulation cover 410, the second cylinder 422 is detachably connected to the top of the first cylinder 421, and the side of the second cylinder 422 facing away from the first cylinder 421 forms an opening 4221.

[0070] Specifically, the first cylinder 421 can be formed integrally with the soundproof enclosure 410, or can be sealed and connected to the soundproof enclosure 410 by welding or gluing. Since the sizes of the films to be measured are inconsistent, in order to adapt to the measurement of films of various sizes, the second cylinder 422 can be designed and manufactured separately, that is, the upper end surface (opening 4221) of the second cylinder 422 is ensured to match the size of the film to be measured. When measuring films of different sizes, only the second cylinder 422 needs to be replaced. This setting can effectively reduce production costs and improve the accuracy of measuring the film to be measured to a certain extent.

[0071] like Figure 3-Figure 9 As shown, in some embodiments, the first cylinder 421 is cylindrical, and the top of the first cylinder 421 is configured with an external thread 4211; the second cylinder 422 is silo-shaped, and the bottom of the second cylinder 422 is configured with an internal thread 4222 to be threadedly connected to the first cylinder 421, and the top surface of the second cylinder 422 is annular in the vertical direction, so as to fix the measured film on the top surface of the second cylinder 422.

[0072] Specifically, in order to realize the quick disassembly and assembly of the first cylinder 421 and the second cylinder 422, an external thread 4211 can be provided on the top outer side wall of the first cylinder 421. The second cylinder 422 is designed to have a cone at the upper part and a columnar structure at the lower part, and the internal structure of the columnar part is provided with an internal thread 4222, which is convenient for threaded connection with the first cylinder 421. The cone design can reduce the size of the second cylinder 422 toward the upper end surface, so as to reduce the area of ​​the upper end surface, which is convenient for the subsequent application or removal of the film on the upper end surface.

[0073] Since an area for pasting the film to be tested needs to be reserved on the upper end surface of the second cylinder 422 , the upper end surface, i.e., the top surface, is annular in vertical projection, and the center area of ​​the annulus is the area of ​​the opening 4221 .

[0074] In some embodiments, taking a film diameter of 2.5 mm as an example, in order to accurately measure the vibration displacement of the film, the height of the first cylinder 421 is between 50 mm and 70 mm, the radius inside the first cylinder 421 is between 12 mm and 16 mm, and the radius outside the first cylinder 421 is between 16 mm and 20 mm; the height of the second cylinder 422 is between 10 mm and 40 mm, the diameter of the top surface of the second cylinder 422 is between 3 mm and 4 mm, and the diameter of the opening 4221 is between 1 mm and 2 mm.

[0075] Specifically, the hollow body 420 is not only configured to transmit acoustic energy, but also to attenuate evanescent waves. Therefore, the hollow body 420 needs to have a certain length (height). For example, the height of the first cylinder 421 can be set to 60 mm, the inner radius of the first cylinder 421 is 14 mm, and the outer radius of the first cylinder 421 is 18 mm. The overall height of the second cylinder 422 in the shape of a granary can be 30 mm, and the ratio of the height of the upper cone to the height of the lower cylinder can be 2, but no specific limitation is made.

[0076] The upper part of the second cylinder 422 can be understood as a truncated cone-shaped structure with the top of the cone flattened, the diameter of the top surface can be 3.5 mm, the diameter of the opening 4221 formed on the top surface can be 2 mm, and the annular area between the opening 4221 and the edge of the top surface is used to stick the edge of the film.

[0077] In some embodiments, the film to be tested is bonded to the top surface of the second cylinder 422 by adhesive.

[0078] Specifically, the back of the film to be tested can be coated with adhesive during production. When in use, the protective film on the back of the film to be tested can be torn off, so that the film to be tested can be quickly and firmly attached to the top surface of the second cylinder 422 .

[0079] Of course, in addition to the above-mentioned form of setting adhesive on the back of the film to be tested, glue can also be coated on the surface of the second cylinder 422 and / or the film to be tested, so as to achieve the purpose of firmly sticking the film to be tested on the top surface of the second cylinder 422, so as to facilitate the subsequent stimulation and measurement of the film to be tested.

[0080] In some embodiments, the displacement sensing element 300 is a laser displacement sensor, and the center of the film to be measured is used to reflect the laser emitted by the laser displacement sensor. Specifically, the displacement sensing element 300 can use an existing laser displacement sensor. To ensure measurement accuracy, the laser displacement sensor needs to be adjusted so that the light spot it emits hits the center of the film to be measured.

[0081] The above laser displacement sensor can be directly arranged on the optical lifting platform 200, but since the base of the optical lifting platform 200 is relatively large, in order to make the light emitted by the displacement sensing element 300 reach the center of the film to be measured, Figure 1 As shown, in some embodiments, the film vibration displacement measuring device further includes an optical plate 700 and an adapter plate 800 which are fixedly connected in sequence along the horizontal direction. One end of the optical plate 700 is fixed to the optical lifting platform 200 , and the adapter plate 800 is used to fix the displacement sensing component 300 .

[0082] Specifically, the optical plate 700 can be used as an extended platform to keep a certain distance between the displacement sensing element 300 and the optical lifting platform 200. The optical plate 700 also has a vibration reduction effect, which can further improve the measurement accuracy. Of course, the optical plate 700 can be used as a component to receive the light reflected back from the measured film, but there is no specific limitation.

[0083] like Figure 2 As shown, in some embodiments, the speaker 430 is embedded in a sound box, and the sound box is disposed in a soundproof enclosure 410; the shape of the soundproof enclosure 410 is adapted to the shape of the sound box.

[0084] Specifically, the speaker 430 can be a four-inch anti-magnetic tweeter, which can be screwed into a solid wood sound box, and the sound box is placed in the soundproof cover 410, so that the sound waves emitted by the speaker 430 can be transmitted along the opening as much as possible. The soundproof cover 410 can be set to a square shape that matches the structure of the sound box, but there is no specific limitation. In order to reduce the production cost of the soundproof cover 410, the soundproof cover 410 can be formed by splicing multiple acrylic plates. Of course, the material of the soundproof cover 410 is not limited to acrylic, but can also be aluminum, steel, etc.; that is, the soundproof cover 410 can be composed of multiple aluminum plates or multiple steel plates spliced ​​together.

[0085] like Figure 1 As shown, in some embodiments, the film vibration displacement measuring device may further include a signal generator 500 and a power amplifier 600. The signal generator 500 is disposed on the supporting platform 100 and is used to generate an excitation signal of a specific frequency; the power amplifier 600 is disposed on the supporting platform 100 and is electrically connected to the signal generator 500 and the speaker 430, respectively.

[0086] Specifically, an excitation signal of a specific frequency is generated by the signal generator 500, and the speaker 430 is excited by the power amplifier to achieve acoustic excitation of the film to be tested.

[0087] In order to realize the collection of measurement data, in some embodiments, the film vibration displacement measuring device also includes a controller and a data acquisition card. The controller is electrically connected to the displacement sensing element 300 to convert the optical signal of the displacement sensing element 300 into an analog signal; the data acquisition card is electrically connected to the controller, and the data acquisition card is used to collect the analog signal and perform analog-to-digital conversion to transmit it to the computer for analysis and display.

[0088] Specifically, Fig.10As shown, during the test, the power of the displacement sensing element 300 (laser displacement sensor), the signal generator 500 and the power amplifier 600 are turned on, and the power line is connected to the two ends of the controller, and the controller can be connected to the laser displacement sensor sensing head and the data acquisition card. After the signal generator 500 is powered on, one of the output ends is set as a sinusoidal signal input and the parameters are adjusted, and connected to the power amplifier 600, and the output end of the power amplifier 600 is connected to the positive and negative poles of the speaker 430.

[0089] Place the film to be measured on the top of the hollow body 420, adjust the adjustment knob 210 of the optical lifting platform 200 so that the laser red dot of the laser displacement sensor is projected on the center of the film to be measured. At this time, the signal light of the laser displacement sensor turns green, indicating that the displacement measurement function can be correctly realized, and there is a reading on the controller display screen.

[0090] The data acquisition card is connected to the analog output on the controller, that is, the corresponding analog voltage on the controller is collected by the data acquisition card and transmitted to the host computer for display and data processing; during the measurement process, the frequency of the signal generator 500 can also be adjusted to obtain displacement values ​​at different frequencies.

[0091] This embodiment uses the provided film vibration displacement measurement device based on acoustic wave excitation to conduct two sets of experimental tests. In the first set of data, the signal generator 500 is set to have a sine wave amplitude of 5V and a frequency of 1kHz. The measured data are as follows: Fig.11 , Fig.12 As shown, Fig.11 The time domain signal diagram obtained for the test, from which the displacement amplitude of the small aperture film can be obtained, Fig.12 The corresponding power spectrum curve is shown in the figure. It can be confirmed that the film does produce a vibration with a frequency of 1kHz under the excitation of the sound wave. The second set of data sets the sine wave amplitude to 5V and the frequency to 3kHz. The measured data is as follows Fig.13 , Fig.14 As shown, Fig.13 The time domain signal diagram obtained for the test can be used to obtain the displacement amplitude of the film. Fig.14 This is the corresponding power spectrum curve. From the figure, it can be confirmed that the input frequency is indeed 3kHz.

[0092] It should be noted that the conversion between displacement and voltage can be: sensor sensitivity refers to the ratio of the output change to the input change of the sensor under steady-state operation. The sensitivity of the laser displacement sensor is 0.1mm / V. Based on this sensitivity, the voltage value can be converted into the corresponding displacement.

[0093] Finally, it should be noted that the above implementation modes are only used to illustrate the present application, rather than to limit the present application. Although the present application is described in detail with reference to the embodiments, a person skilled in the art should understand that various combinations, modifications or equivalent substitutions of the technical solutions of the present application do not depart from the spirit and scope of the technical solutions of the present application, and should be included in the scope of the claims of the present application.

Claims

1. A film vibration displacement measuring device based on acoustic wave excitation, characterized in that: include: Support platform; An optical lifting platform, fixed on the supporting platform, the optical lifting platform comprising an adjustment knob and a scale mark; A displacement sensing component is installed on the optical lifting platform so that the height of the displacement sensing component can be adjusted by the adjusting knob; An acoustic excitation structure is arranged on the supporting platform and opposite to the displacement sensing element, the acoustic excitation structure comprises a speaker, a soundproof cover and a hollow body, the speaker is located in the soundproof cover, and the soundproof cover has an opening on a side facing the displacement sensing element; The hollow body extends in a vertical direction, and the bottom end of the hollow body is arranged at the opening of the sound insulation enclosure. The top end of the hollow body has an opening, and the opening is connected to the inner cavity of the sound insulation enclosure. The hollow body is configured to carry the film to be measured and transmit acoustic excitation energy to the film to be measured.

2. The film vibration displacement measuring device based on acoustic wave excitation according to claim 1 is characterized in that: The hollow body has a hollow area, and the diameter of the hollow area is greater than or equal to the diameter of the opening; The diameter of the opening is adapted to the size of the film to be measured.

3. The film vibration displacement measuring device based on acoustic wave excitation according to claim 2 is characterized in that: The hollow body includes a first cylinder and a second cylinder. The bottom end of the first cylinder is fixed to the opening of the soundproof enclosure. The second cylinder is detachably connected to the top of the first cylinder. The opening is formed on a side of the second cylinder facing away from the first cylinder.

4. The film vibration displacement measuring device based on acoustic wave excitation according to claim 3 is characterized in that: The first cylinder is in a columnar shape, and the top of the first cylinder is configured with an external thread; The second cylinder is in the shape of a granary, and the bottom of the second cylinder is configured with an internal thread for threaded connection with the first cylinder. The top surface of the second cylinder is annular in the vertical direction, so that the film to be tested can be fixed on the top surface of the second cylinder.

5. The film vibration displacement measuring device based on acoustic wave excitation according to claim 4 is characterized in that: The film to be tested is bonded to the top surface of the second cylinder by adhesive; The displacement sensing component is a laser displacement sensor, and the center of the film to be measured is used to reflect the laser emitted by the laser displacement sensor.

6. The film vibration displacement measuring device based on acoustic wave excitation according to any one of claims 1 to 4, characterized in that: The film vibration displacement measuring device further comprises an optical plate and an adapter plate which are fixedly connected in sequence along a horizontal direction, one end of the optical plate is fixed to the optical lifting platform, and the adapter plate is used to fix the displacement sensing component.

7. The thin film vibration displacement measuring device based on acoustic wave excitation according to any one of claims 1 to 5, characterized in that: The speaker is embedded in a sound box, and the sound box is arranged in the soundproof enclosure; The shape of the sound insulation cover is adapted to the shape of the sound box.

8. The film vibration displacement measuring device based on acoustic wave excitation according to any one of claims 1 to 5, characterized in that: The film vibration displacement measuring device also includes: A signal generator, disposed on the supporting platform, for generating an excitation signal of a specific frequency; The power amplifier is arranged on the supporting platform and is electrically connected to the signal generator and the speaker respectively.

9. The film vibration displacement measuring device based on acoustic wave excitation according to claim 8, characterized in that: The film vibration displacement measuring device also includes: A controller, electrically connected to the displacement sensing element, to convert the optical signal of the displacement sensing element into an analog signal; A data acquisition card is electrically connected to the controller, and is used to acquire the analog signal and perform analog-to-digital conversion so as to transmit the analog signal to a computer for analysis and display.

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